Which 2-2 are as good or better than a 2-1?

[Reddog74usa]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

[Hoist!]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

If you're talking bottom end and mid-range performance, NONE!!!

Hoist!

[Admiral Akbar]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ.. Running a 95 Kromewerks ARIIIs do well. Bigger motors seem to like the Kromewerks AR100s but I've founf that they like a little tweaking to get the most out of them..

Max

[TOMCENTRAL]

I ran a V&H Pro-Pipe & a set of V&H tru duals w/0vals(not monster 0s) on my 07 SG & the dyno sheets were very similar.Power idenical.Regards,Tom

[TOMCENTRAL]

I like the SuperMeg the best for my application on my 09 build.Regards,Tom

[Sc00ter]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ.. Running a 95 Kromewerks ARIIIs do well. Bigger motors seem to like the Kromewerks AR100s but I've founf that they like a little tweaking to get the most out of them..

Max

Probably more to do with your cams then the pipes, don't you think?

[GoFast.....]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

I stand by the rhineharts and have the dyno sheets to prove it. Check out my stock 07 96" with true dials

[Sc00ter]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

On a basically stock motor, you may not see much of a difference either way, but on a motor with any kind of flow (bigger throttle body, good heads, decent cam), and a competent tune, a 2 into 1 exhaust will produce more torque faster than any 2 into 2 exhaust.

[Faast Ed]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ

I didn't lose any low end when I switched to a Fatcat. I have a Softail so I didn't even get the infamous dip that the Baggers are getting with that pipe.

[Hoist!]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ

I didn't lose any low end when I switched to a Fatcat. I have a Softail so I didn't even get the infamous dip that the Baggers are getting with that pipe.

The dip might be in the tune! I have none with the FatCat on (2) 110 motors. One a Hi-Po TC in a '07 SERK, and one a RevTech carb'd Evo in a '85 FXWG! The type of bike don't cause the dip. And some dips can't be tuned like with a Thuderheader sometimes. But I had no problem getting mine right. Like everything else, ALL has to be a properly matched combination. Might need to look at your headwork and TB size if you've got a dip.

Hoist!

[Sc00ter]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ

I didn't lose any low end when I switched to a Fatcat. I have a Softail so I didn't even get the infamous dip that the Baggers are getting with that pipe.

The dip might be in the tune! I have none with the FatCat on (2) 110 motors. One a Hi-Po TC in a '07 SERK, and one a RevTech carb'd Evo in a '85 FXWG! The type of bike don't cause the dip. And some dips can't be tuned like with a Thuderheader sometimes. But I had no problem getting mine right. Like everything else, ALL has to be a properly matched combination. Might need to look at your headwork and TB size if you've got a dip.

Hoist!

No dip with my D&D Fatcat here either - but I have a HPI 62mm throttle body, Wes Brown Cycle Rama heads and Cams and a John Golden "Rolling Thunder" tune...    I have about 110 ft.lbs. of torque to 2500 rpm and 120 ft.lbs of torque at 5800.  Pretty straight line in between...   

[Hoist!]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ

I didn't lose any low end when I switched to a Fatcat. I have a Softail so I didn't even get the infamous dip that the Baggers are getting with that pipe.

The dip might be in the tune! I have none with the FatCat on (2) 110 motors. One a Hi-Po TC in a '07 SERK, and one a RevTech carb'd Evo in a '85 FXWG! The type of bike don't cause the dip. And some dips can't be tuned like with a Thuderheader sometimes. But I had no problem getting mine right. Like everything else, ALL has to be a properly matched combination. Might need to look at your headwork and TB size if you've got a dip.

Hoist!

No dip with my D&D Fatcat here either - but I have a HPI 62mm throttle body, Wes Brown Cycle Rama heads and Cams and a John Golden "Rolling Thunder" tune...    I have about 110 ft.lbs. of torque to 2500 rpm and 120 ft.lbs of torque at 5800.  Pretty straight line in between...   

Wow! What a coincidence! HeHe!!! Same heads, same TB, but a REAL bottom end too!!! Perfect tune by Bean of Big Boyz with a SERT and getting very similar numbers!

















HeHe!!! But you already knew that!

Hoist!

[GoFast.....]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

On a basically stock motor, you may not see much of a difference either way, but on a motor with any kind of flow (bigger throttle body, good heads, decent cam), and a competent tune, a 2 into 1 exhaust will produce more torque faster than any 2 into 2 exhaust.

we will See if that is true in about a month

[ejk_dyna]

<<Heck most 2 into 1 seem to loose low end but pick up on peak TQ>>

On dyna's which have headpipes w/ crossover Cs slip-ons have more low end meaning 2500 and below than a good 2-1 for sure.  So I think that is what Bruce is talking about.  From 3,000 to 4500 it is no contest...the 2-1 is way stronger in the mid-range.  Don't know about other head pipe configurations.

<<The type of bike don't cause the dip.>>

Actually the bagger fatcat configuration does typically produce a dip in the 3500 rpm area.  The softail/dyna pipes never do.  It is not a tuning issue per se in that if a particular build-up has it you can't tune it out.  But I have also seen bagger builds that don't have the dip...but not as many.  There is something about the bagger pipe that is more sensitive to component make-up.  Bob (FLTRI) who is an exceptional tuner has seen this again and again.  I think he might have had a back to back where they swapped to a supermeg and the dip went away.  Too bad he is not posting here anymore...

[Admiral Akbar]

A lot of this is matching the pipe to the build.. Putting a Fatcat on a bigger build can eliminate the dip but then you are probably giving up some HP up top. Toss a Boarzila on there and you'll get the HP back plus the dip.. Trap type pipes are cool cuz they can adjust the tuning some..

No dip? lets see a dyno sheet..  Max

[Hoist!]

A lot of this is matching the pipe to the build.. Putting a Fatcat on a bigger build can eliminate the dip but then you are probably giving up some HP up top. Toss a Boarzila on there and you'll get the HP back plus the dip.. Trap type pipes are cool cuz they can adjust the tuning some..

No dip? lets see a dyno sheet..  Max

OMG, somebody gets it!!!

Hoist!

[Hoist!]

Ok, here's the final run after all the testing we did. I've subsequently gone with a SERT so I'd have an ECM that can run my bike. But no components were changed, and had similar results. Different Dyno, different technique, but the curve's the same. And with the SERT, it was tuned by combustion efficiency method, not AFR, which I'm a true believer in! Numbers don't matter to me at all. The shape of my torque curve is ALL I care about! Sorry I don't have the SERT tuned run on my computer. But it was tuned by Bean of Big Boyz, and believe me, the shape of the curve's the same! And don't go by the dip below 2000 RPM. No HD, especially a stroker, should EVER be ridden down there anyway! Didn't even really tune down there! Now try to tell me my bike don't ride the way the shape of that torque curve looks! That curve WAS MY GOAL!!!

ADDED: Joe's a PC guy and Bean's a SERT guy. I'm friends with both of em!

And yes, I travel 500 miles round trip for a perfect tune!!!

Hoist!

[attachment removed after 60 days by system]

[torque4me]

did you sit on that dyno sheet or something? all squished ... what does it look like when it isnt all compressed?
thanks

[Hoist!]

did you sit on that dyno sheet or something? all squished ... what does it look like when it isnt all compressed?
thanks

Exactly the way it came off of Joe's printer! Is there a problem?
If you're referring to the size, click on it and it'll go to full size!

Hoist!

[Twolanerider]

Have to follow on Howie's, Scott's and other's satisfaction with the Fatcats.  Have them on a 107 build that offers fair performance and a basically stock 95" on an old Road Glide.  On both bikes the torque is in early and well.  Excelling pulling baggers.  With the remainder of the builds matched up nicely and a good tune no dip problems with either of them either.

The only mufflers I ever had even close to comparable performance out of when using duals compared to 2-1 was the old White Brothers E Series mufflers.  Though they've not been available for several years now.  Too bad as they were great mufflers for anyone wedded to the true dual look.  They could be tuned to pull nearly as well as a good 2-1 and they sounded great.

Competely satisfied in the FatCats with their quiet baffle option though.  The bikes run great.  Like the sound.  And (I think I mentioned this) the bikes run great .

[Reddog74usa]

The bike is an FXR with a 113. I know the Fatcat is good performer but there a heavy pipe compared to most other 2-1's. I already have a Bassani RR but wanted to see what other options are out there. I also have a set of Cycle Shack slipon's and was thinking of running a set of later model FXD oem header pipes with them however I think I'll stay with the Roadrage. Thanks for the replies.

[metaliser]

I installed a fatcat with the quiet baffle and took a little ride and it hurt my low end but it was not tuned for that pipe, it was tuned for V&H's tru duals with rush mufflers 2" baffles, so after my little trip up the rd I came back and pulled the heads to get 10.1 comp and put in the singh grooves, I'm waiting on valcon releases and after that I will get a new tune and then I will let you know how it does, I will post a dyno sheet but it will be after it warms up a little.
So here's what it will be when it's dynoed, 95" 10.1 comp, hq 0034 gear drive's, KB flatops with 30 thous hg,BigBoyz street port, Fatcat with the quiet baffle,SE ac and a PCIII, will see how it turns out. 

[Dennis The Menace]

I'll play.  Throw in a crossover on 2-2's now.  Got it on my Bub 7's, and they have more power and TQ than true duals.  Not sure what this means to the 2-1 vs 2-1 argument, but worth mixing it up a bit.

My father raced cars back in the 70's, and even back then it was well understood that the pipe needed to be matched to the characteristics of the exhaust port for that cyclinder, as well as tuned at the header collector.  Of course, you didnt have pipes and mufflers to deal with in racing, but same principles are at work--you have to tune the flow from the cylinder and deal with the reversion and sound waves/frequencies and also gases in order to get the maximum flows...all the way down the pipe and out the outlet of the muffler!

What was often ignored except by the best equipped race teams, at least in the 70's, was that an engine could actually gain a slight amount of power from an effectively designed exhaust system.  The (properly designed) exhaust pipe acts to help evacuate all spent gases on the blow stroke, a clean cylinder will fill more effectively and with greater efficiency since the air in the cyclinder at intake is purely intake air--and not residual exhaust/spent gases.

Anyway, that is what I learned way back in the day, and have seen this explained in other articles dealing with the finer points of exhaust, but both auto racing and motorcycle racing experts.

So, extrapolating this to todays motors and builds, I think it only fair to say that what works great for one build, may not work for another.  At best, it depends.  So, one cannot say that a 2-1 is better than a 2-2, because only in certain specific cases is it true.  Or the converse.

Its about as effective as arguing that a wide tire is better than a narrow tire.  It depends on the application, and how well its applied to that use too!  But, pipes must be designed well in order to be most effective.  But, you all know that...sorry to bore everyone.

menace

[Sc00ter]

I'll play.  Throw in a crossover on 2-2's now.  Got it on my Bub 7's, and they have more power and TQ than true duals.  Not sure what this means to the 2-1 vs 2-1 argument, but worth mixing it up a bit.

My father raced cars back in the 70's, and even back then it was well understood that the pipe needed to be matched to the characteristics of the exhaust port for that cyclinder, as well as tuned at the header collector.  Of course, you didnt have pipes and mufflers to deal with in racing, but same principles are at work--you have to tune the flow from the cylinder and deal with the reversion and sound waves/frequencies and also gases in order to get the maximum flows...all the way down the pipe and out the outlet of the muffler!

What was often ignored except by the best equipped race teams, at least in the 70's, was that an engine could actually gain a slight amount of power from an effectively designed exhaust system.  The (properly designed) exhaust pipe acts to help evacuate all spent gases on the blow stroke, a clean cylinder will fill more effectively and with greater efficiency since the air in the cyclinder at intake is purely intake air--and not residual exhaust/spent gases.

Anyway, that is what I learned way back in the day, and have seen this explained in other articles dealing with the finer points of exhaust, but both auto racing and motorcycle racing experts.

So, extrapolating this to todays motors and builds, I think it only fair to say that what works great for one build, may not work for another.  At best, it depends.  So, one cannot say that a 2-1 is better than a 2-2, because only in certain specific cases is it true.  Or the converse.

Its about as effective as arguing that a wide tire is better than a narrow tire.  It depends on the application, and how well its applied to that use too!  But, pipes must be designed well in order to be most effective.  But, you all know that...sorry to bore everyone.

menace

Just curious...what type of racing did your father do?

[Sc00ter]

Ok, here's the final run after all the testing we did. I've subsequently gone with a SERT so I'd have an ECM that can run my bike. But no components were changed, and had similar results. Different Dyno, different technique, but the curve's the same. And with the SERT, it was tuned by combustion efficiency method, not AFR, which I'm a true believer in! Numbers don't matter to me at all. The shape of my torque curve is ALL I care about! Sorry I don't have the SERT tuned run on my computer. But it was tuned by Bean of Big Boyz, and believe me, the shape of the curve's the same! And don't go by the dip below 2000 RPM. No HD, especially a stroker, should EVER be ridden down there anyway! Didn't even really tune down there! Now try to tell me my bike don't ride the way the shape of that torque curve looks! That curve WAS MY GOAL!!!

ADDED: Joe's a PC guy and Bean's a SERT guy. I'm friends with both of em!

And yes, I travel 500 miles round trip for a perfect tune!!!

Hoist!

My build is essential identical to Howie's - and even though I used a different tuner - (I used John Golden - Rolling Thunder - Joplin, Mo) - our dyno sheets are virtually the same.  I have a slightly leaner overall fuel curve, but the torque and horsepower curves are much the same.  At 75 or so mph, I average about 40mpg.

[Sc00ter]

Have to follow on Howie's, Scott's and other's satisfaction with the Fatcats.  Have them on a 107 build that offers fair performance and a basically stock 95" on an old Road Glide.  On both bikes the torque is in early and well.  Excelling pulling baggers.  With the remainder of the builds matched up nicely and a good tune no dip problems with either of them either.

The only mufflers I ever had even close to comparable performance out of when using duals compared to 2-1 was the old White Brothers E Series mufflers.  Though they've not been available for several years now.  Too bad as they were great mufflers for anyone wedded to the true dual look.  They could be tuned to pull nearly as well as a good 2-1 and they sounded great.

Competely satisfied in the FatCats with their quiet baffle option though.  The bikes run great.  Like the sound.  And (I think I mentioned this) the bikes run great .

[/color]

Another John Golden tune!

[Dennis The Menace]

Hey Scooter...old man raced and built exhaust systems for local dirt track racers in Oregon in the 60's and 70's.  1/4 mile late models.  Some of the local guys went on to NASCAR involvement of some sort.  Harold Hardesty came to southern Oregon after his NASCAR career, and drove for awhile for fun.  He did real well, and was a favorite.

[Admiral Akbar]

"OMG, somebody gets it!!! Thumbs Up Thumbs Up Thumbs Up"

Shoulda known it was Joes..  Looks good.. I run a Bassani on a 116 dyna and last check it was 4 hp compared to a set of 2 into 2 I had.. I think one thing most are forgetting here is that there is a difference in performance between true duals on a bagger and those on an FXR or Dyna.. Which is what the discussion is about here.. True duals on a bagger are usually way different in length. It's harder to get them to tune well.. Cycle shack makes a stagger dual for baggers that are equal lenght.. But no on seem to run them..

Menace,

Definitely with you on the pipe tuning.. In the early 70s, I learned you build a motor best you can then spend time on the dyno cutting stuff up until you find your numbers.. Saw a 250 cc 4 stroke single go from 24 hp rear wheel to 34 HP rear wheel with pipe / intake and tuning alone.. Not bad considering that a stock 71 CB750k1 got 34 on the same dyno.. Now the water cooled 4 stroke singles regularly crank out about 34 ponies.

BTW,

RD, I'd use the Bassani sense you already got it, don't think the CSs flow enough to work well with a 113.. If you were trying to recover some low end on a 95 ci motor running the bassani.. I'd bet the CSs would do better but might not give you the top end HP. I'd bet that you could squeeze more out that motor with a good 2 into 2 than the Bassani though.

Max

[Sc00ter]

Hey Scooter...old man raced and built exhaust systems for local dirt track racers in Oregon in the 60's and 70's.  1/4 mile late models.  Some of the local guys went on to NASCAR involvement of some sort.  Harold Hardesty came to southern Oregon after his NASCAR career, and drove for awhile for fun.  He did real well, and was a favorite.

Always fun to hear from those with a racing background.   

My father raced Road Racing for almost 50 years and my god-father was one of the top midwest pavement short track guys around.  As a result, much of my life has been at one race track or another.  My father retired from road racing in the mid 90's and my god-father died of cancer a few years back (althought his son is still an occaisional Nationwide/Truck Series Nascar crew chief).

[Twolanerider]

Another John Golden tune!

Definitely.  When he's that close and that good and makes the bikes that happy it's a no brainer.  Feel sorry for the poor bastards that don't have good tuners within easy range.

[jazzman713]

i have been looking at the s&s slip on for some time and have been told a couple times they are good pipes but i never hear anyone talk about them i know they dont look good like others but im not into looks just want a good ride

[sean fxd]

<<did you sit on that dyno sheet or something? all squished ... what does it look like when it isnt all compressed?>>

Another typical Joe's sheet.  All scrunched up to make the tq curve look better.  Uncorrected power numbers, blah, blah.  And yes everyone knows he is a great tuner.

<<it was tuned by combustion efficiency method, not AFR, which I'm a true believer in!>>

OK i'll bite.  What exactly is this method of tuning?  Using a term like that I hope it is more than just tuning to best power regardless of exact AFR.

<<Sorry I don't have the SERT tuned run on my computer. But it was tuned by Bean of Big Boyz, and believe me, the shape of the curve's the same!>>

So did BigBoyz tune this exact bike in same configuration as Joe's?  I would love to see that dyno sheet, especially if it is SAE which most BB sheets are, IIRC.

Sean

[sean fxd]

<<A lot of this is matching the pipe to the build>>

Max- obviously if FLTRI was able to change the fatcat bagger pipe to a supertrapp and the dip went away it was a pipe issue...assuming that FLTRI tuned properly which is a good bet.  But you see similar (or identical) builds on softails/dyna's with fatcat that don't have the dip so it seems that there is something specific to that pipe configuration that causes this dip.

Sean

[Hoist!]

<<did you sit on that dyno sheet or something? all squished ... what does it look like when it isnt all compressed?>>

Another typical Joe's sheet.  All scrunched up to make the tq curve look better.  Uncorrected power numbers, blah, blah.  And yes everyone knows he is a great tuner.

<<it was tuned by combustion efficiency method, not AFR, which I'm a true believer in!>>

OK i'll bite.  What exactly is this method of tuning?  Using a term like that I hope it is more than just tuning to best power regardless of exact AFR.

<<Sorry I don't have the SERT tuned run on my computer. But it was tuned by Bean of Big Boyz, and believe me, the shape of the curve's the same!>>

So did BigBoyz tune this exact bike in same configuration as Joe's?  I would love to see that dyno sheet, especially if it is SAE which most BB sheets are, IIRC.

Sean

Gotta love it!!! Very passionate subject this dyno tuning chit, believers and disbelievers, and who's full of crap and who's not!!! No agenda for me man. My bike, my testing, my tunes, done by people I know and people I trust. So I'll give ya the benefit of the doubt that your post was good spirited and I'll just respond. My suggestion is that you simply ask a question instead of using a cynical tone to it with people you don't know FWIW!!!

The bike was tuned twice at Big Boyz. This is the first tune from last June, '08. I went back to visit them again in Sept, and spent some time getting her tweaked and fine tuned. That last fine tune got her perfect. This tune was good, but we were able to squeeze more out of the top end performance, which I knew felt a lil off up top. We spent a lot of time just tweaking after a day and a half building this first map. WOT numbers went up and so did my gas mileage, as well as eliminating some popping I was still getting.

Reason I say numbers don't matter is that ALL dynos are different. Rather than debating dyno tuning with you, which I'm no expert at (which is why I have an expert do it and not me), I'll defer to springer-, who I'm sure will be happy to chime in and explain the combustion tuning process for you.

That all said, the first chart is the sweep run, and the second the WOT run. Hopefully springer- at some point can get me the final runs from Sept, as I had a wedding I was running very late for in Portland that same day. But these charts give you an idea. Joe's charts are squished, so what! Look at the numbers and with 100 at 2000 and climbing, then dropping to 100 at 6000 on Joe's chart, is what I was referring to as being a flat curve. I hope you don't think I'm that lame that I was only referring to the shape without relating it to the numbers!!! I've nothing to prove and am not afraid to share, so as you asked, here's my preliminary charts from Big Boyz. All I can say is my bike pulls like a mutha! And if ya don't know me, ask around. I ride the living chit out of my bikes, break my share of chit doing it, and sometimes have more balls than brains when I'm racing. Just relax a lil and use this information, not to tear it apart, but simply from someone who's put a lot of time and effort into getting his bike to run as good as possible, and willing to share the information with you.

Hoist!

[attachment removed after 60 days by system]

[Hoist!]

Second run at WOT.

Hoist!

[attachment removed after 60 days by system]

[Hoist!]

Really wish I had the Sept run too, but believe me, I LOVE THE WAY MY BIKE RUNS AND THAT's ALL THAT MATTERS!!!

Hoist!

[GoFast.....]

I am going to test a 2 into 2. Let the pipe cool down enough to take it off and then dyno it with a 2 into 1 at the ended of this month, I do not think testing on two diffrent dynos will work as a comparesion and diffrent days on the same dyno. To many diffrent variable factors to deal with.

[ejk_dyna]

<<So I'll give ya the benefit of the doubt that your post was good spirited and I'll just respond. My suggestion is that you simply ask a question instead of using a cynical tone to it with people you don't know FWIW!!!>>

Hoist,

I don't think Sean was trying to get your goat in any way.  You seem like a really positive, committed HD guy which is great for HTT.

Because you are new to HTT you don't have the "backstory" on things...and one of those things is Joe's...LOL.  Lot of discussion about his dyno sheets, the high readings, uncorrected, squinched up tq scale which makes the tq curve appear flat.  None of that is your problem.  I think everyone acknowledges he is a hell of a tuner.  That's where that came from...no need to reopen that can of worms.

Looking at Bean's dyno sheet (it is a Factory Pro so that has it's own comparability issues with DJ250...great dyno though)  just curious what you build specifics are with a tq peak at 4500-4800rpm.

I would also like to hear exactly what the "combustion efficiency" tuning method is.

Thanks

[Faast Ed]

I am going to test a 2 into 2. Let the pipe cool down enough to take it off and then dyno it with a 2 into 1 at the ended of this month, I do not think testing on two diffrent dynos will work as a comparesion and diffrent days on the same dyno. To many diffrent variable factors to deal with.

Good news.   When I was changing baffles during a dyno playday last year, we used the mini blowers aiming at the pipes (same kind of blowers they cool your motor with) and them pipes cooled off remarkably fast! Made it conveneint to horse around with baffle changes.

[dakota224]

 python 3`s are about as good as it gets when it comes to 2 into 2 pipes for softails & dynas.. look  at  www.nightrider.com and check the Exhaust comparison chart..  Thunderheader slipons are good for baggers.

[Scramjet]

<<So I'll give ya the benefit of the doubt that your post was good spirited and I'll just respond. My suggestion is that you simply ask a question instead of using a cynical tone to it with people you don't know FWIW!!!>>

Hoist,

I don't think Sean was trying to get your goat in any way.  You seem like a really positive, committed HD guy which is great for HTT.

Because you are new to HTT you don't have the "backstory" on things...and one of those things is Joe's...LOL.  Lot of discussion about his dyno sheets, the high readings, uncorrected, squinched up tq scale which makes the tq curve appear flat.  None of that is your problem.  I think everyone acknowledges he is a hell of a tuner.  That's where that came from...no need to reopen that can of worms.

Looking at Bean's dyno sheet (it is a Factory Pro so that has it's own comparability issues with DJ250...great dyno though)  just curious what you build specifics are with a tq peak at 4500-4800rpm.

I would also like to hear exactly what the "combustion efficiency" tuning method is.

Thanks

Hoist,

I am of the same opinion as Sean.  There is a lot of history on this and I do not think EJK Dyna was trying to imply anything between the lines.

For example, my D&D Fatcat build has a 3 TQ dip at 100TQ at 3500 RPM.  You simply can not see that dip when the scale is compressed.

B

For the original post; in a moderate build the Cycle Shack slip-ons on factory head pipes with crossovers will perform well.

[Sc00ter]

My tune...  110 CI, Wes Brown Cycle Rama heads, Cycle Rama cams, HPI 62mm throttle body and air cleaner, Axtell cylinders, CP Pistons and rings, S&S limited travel lifters, SE tapered pushrods, SE roller rocker arms, Feuling camplate, Feuling Oil Pump, Cometic gaskets, D&D Fatcats with quiet performance baffles - built by me and tuned by John Golden - Rolling Thunder Dyno - Joplin, Mo.   approx. 40 mpg at 75/80 mph freeway speeds - and no torque dip...

[attachment removed after 60 days by system]

[Hoist!]

<<So I'll give ya the benefit of the doubt that your post was good spirited and I'll just respond. My suggestion is that you simply ask a question instead of using a cynical tone to it with people you don't know FWIW!!!>>

Hoist,

I don't think Sean was trying to get your goat in any way.  You seem like a really positive, committed HD guy which is great for HTT.

Because you are new to HTT you don't have the "backstory" on things...and one of those things is Joe's...LOL.  Lot of discussion about his dyno sheets, the high readings, uncorrected, squinched up tq scale which makes the tq curve appear flat.  None of that is your problem.  I think everyone acknowledges he is a hell of a tuner.  That's where that came from...no need to reopen that can of worms.

Looking at Bean's dyno sheet (it is a Factory Pro so that has it's own comparability issues with DJ250...great dyno though)  just curious what you build specifics are with a tq peak at 4500-4800rpm.

I would also like to hear exactly what the "combustion efficiency" tuning method is.

Thanks

HeHe!!! It took so long to type this that Scott already answered. We have similar builds. Here's my story!

Thanks for you explanation ejk! You're right, no idea of the history at all. I've heard people question his numbers, but like I said, it was never about the numbers to me. It's about how my bike runs , feels, and seat of the pants! My ass dyno tells me all I need to know. Were it a carb, I'd need no dyno. With this FI stuff, the only way to get it best is to make the right map for your build. So I first put a PC on and hightailed it to Upstate NY to meet Joe. Him and I subsequently became good friends. He got my bike running awesome, and I was very happy with it except for gas mileage. But I really wanted an ECM that could control my motor, not an add-on device to do it. So I wound up researching and travelled all the way to Augusta, ME to have Bean tune my bike with the SERT. Again, same result. Bean and springer_ and I also became friends as a result. I was happy with Bean's tune, but also felt like it was detuned up top, and had a lil popping. So back I went in Sept and Bean NAILED it this time. Now it runs like the same MoFo Joe made it, but with good gas mileage to boot. Not one to care about the numbers themselves, the shape of the curves are what I'm after. It was  component tested at Joe's by trying many things after it was designed a certain way by Wes Brown. Between myself, Wes, and Joe, and Wes sending us stuff to try at our request, we got that motor doing what it should. And I was very happy with the result. HeHe!!! Then Scott built his!!!

It's an '07 SERK. The build consists of Wes Brown custom made CVO 110 heads made from HD blanks! Don't have the specs as I trusted his design. But my builder spoke highly of his headwork. It was milled 0.040" and use Cometic 0.030" HG's, for a static CR of 9.8:1. It had Feuling camplate oil pump, pushrods, race lifters, TP Roller Rockers and Rocker Boxes, 4" Axtell Barrels w/CP forged pistons and I'm using Wes' custom ground CR 590G cams designed for the CVO 110 motor specifically. The bottom end is converted to a Timken bearing design with S&S forged 3/8" leg built in CVO 110 cases. It uses a 62m HPI TB w/HPI hi-flow A/C assembly. So that's the crux of the engine components. That was til I blew it up at the end of last season again! Well blown up's a lil strong. Wiped out a front intake lifter and still raced that thing all over the Smoke Mountains for a week after I felt/heard it go, and still rode the chit out of it back up to NYC. ALL with my OL on the back and loaded with luggage!!!

Now the motor is built by North Shore MC in New Hyde Park, LI, NY, by a close friend Vern, who's been doing my motors for 15 years, does our whole crews motors, and been building motors for over 25 years. I'm detuning it now per Vern's advice so it'll hold together a lil better since Vern knows my maniac riding style very well. After all, I learned it from him. Most of what I know was taught to me by hanging around Vern's shop all these years, and watching him build motors and partying til 4 AM some nights. It's what I love! It's what we all do! It's our passion, not a friggin hobby or sport. IT'S MY LIFE!!!

This build will now have Vern rebuilt heads, S&S 585G cams, S&S Lifters w/limiters, S&S pushrods, same Ps and C's-recrosshatched with new rings, and the same RB assembly. The same bottom end components with the bottom end rebuilt after a thourough cleaning including a Baker plus 1 OP and new oil cooler core. I'm not taking no chances of contamination from the failed lifter. Then back to Bean I'll go after breakin to have her retuned. I hope I'm happy with the milder build. But I have 4 other bikes I can get my rocks of with when I want. This is my Touring Bike and needs to hold together. I'll go out on my Vern built lil 514lb '89" Evo on a Boyce Pro Street swingarm frame w/5-speed trans. That bike FLIES!!! I have a '99 CVO FXR3 in Blue Flame, 1 of only 64 ever made. I have a completely rebuilt '85FXWG with RevTech 110" Evo and RT 6-speed trans, Traxxion Dynamics Suspension, and PM everything else. I used the takeoffs from my original 4-speed Evo FXWG to build a Paugho Wishbone frame Bobber out of just for S&G!!!

So yes, I'd say I'm committed, or better yet, maybe need to be committed! I thank you for noticing and appreciate the way you've addressed me. I would not have gotten so defensive had I been addressed that way from the start. But hey, I'm the Newbie here!!! Even though I'm way not a Newbie, I guess I start from scratch on this Board! So hey, give the Newbie some chit! I might have skinny arms, but got pretty big shoulders!!!

Hoist!

[Hoist!]

<<So I'll give ya the benefit of the doubt that your post was good spirited and I'll just respond. My suggestion is that you simply ask a question instead of using a cynical tone to it with people you don't know FWIW!!!>>

Hoist,

I don't think Sean was trying to get your goat in any way.  You seem like a really positive, committed HD guy which is great for HTT.

Because you are new to HTT you don't have the "backstory" on things...and one of those things is Joe's...LOL.  Lot of discussion about his dyno sheets, the high readings, uncorrected, squinched up tq scale which makes the tq curve appear flat.  None of that is your problem.  I think everyone acknowledges he is a hell of a tuner.  That's where that came from...no need to reopen that can of worms.

Looking at Bean's dyno sheet (it is a Factory Pro so that has it's own comparability issues with DJ250...great dyno though)  just curious what you build specifics are with a tq peak at 4500-4800rpm.

I would also like to hear exactly what the "combustion efficiency" tuning method is.

Thanks

Hoist,

I am of the same opinion as Sean.  There is a lot of history on this and I do not think EJK Dyna was trying to imply anything between the lines.

For example, my D&D Fatcat build has a 3 TQ dip at 100TQ at 3500 RPM.  You simply can not see that dip when the scale is compressed.

B

For the original post; in a moderate build the Cycle Shack slip-ons on factory head pipes with crossovers will perform well.

HeHe!!! I don't consider that a dip! Hell I don't even ride down there. When you talk dip, talk dip I'd feel! 3 ft-lbs at the bottom, WTF cares about that!!!

Hoist!

[Faast Ed]

   Another way to get rid of the D & D dip is to scrap the Bagger for a Softail.   
Softies don't seem to be experiencing that.   Pretty sensible idea, no?   

[Sc00ter]

  Another way to get rid of the D & D dip is to scrap the Bagger for a Softail.   
Softies don't seem to be experiencing that.   Pretty sensible idea, no?   

hehe...   

no - not such a good idea...

But like I said earlier....what dip?

[Hoist!]

  Another way to get rid of the D & D dip is to scrap the Bagger for a Softail.   
Softies don't seem to be experiencing that.   Pretty sensible idea, no?   

hehe...   

no - not such a good idea...

But like I said earlier....what dip?

HeHe!!! I like dip! Onion Dip with Ruffles please!!! Rrrrrrrrrrrrruffles Have Rrrrrrrrrrrrrrridges!!!

Hoist!

[Don D]

Hoist sounds like a hot ride and through build, details! Good job
I am sure you now know about the Feuling race lifters and issues and it might be an idea to turn the valve spring pressure down a notch too, those 585s are soft lift compared to some grinds out there. Even with big valves 175# on the seat high 300s open is adequate JMHO.

[Hoist!]

Hoist sounds like a hot ride and through build, details! Good job
I am sure you now know about the Feuling race lifters and issues and it might be an idea to turn the valve spring pressure down a notch too, those 585s are soft lift compared to some grinds out there. Even with big valves 175# on the seat high 300s open is adequate JMHO.

Thanks man! We're using single spring S&S springs, setup for the 585's. Vern uses em all thee time W/O issue. Don't think the'yre even that strong.  I'm familiar now with the whole Feuling lifter and spring pressure thing. Wes built the heads the first time. Prolly oversprung. Now we're building the entire motor ourselves-Vern's way, so everything will be the correct component selection and assembled properly. That motor was the last time I tell Vern what I want to use. I went to Wes because he designed my package SPECIFICALLY for the CVO 110. And it sure was a runner!!! Just not a laster! I'll take just a wee less of a runner if I can get a laster this time too! And I think a Vern Built 110 will get me there. All my other Vern Builts always did!!!

Hoist!

[Admiral Akbar]

You are running 585s, Fatcat and no dip? I'm impressed.  Max

[springer-]

The equipment we use to tune is different than most other tuners use.  Most (probably 99%) tune with AFR.  We don't use AFR for tuning, we can't see the AFR, have no way to measure AFR and don't adjust for AFR.

We use combustion science to tune the engine. When fuel is burned it is a chemical reaction. The chemical reaction gives off by products, these are the emissions. CO, CO2, HC and O2 are all emission in the exhaust gasses. AFR only looks at the O2, the least important in the equation. Carbon Monoxide, CO is partially burned fuel. Carbon Dioxide, CO2 is fully burned fuel. Hydrocarbons, HC is raw unburned fuel. Oxygen, O2 is left over that isn't used in the combustion process.  We look at the emissions in the exhaust gasses. The gas readings give us indications of how the timing is, if there is too much or to little fuel for the amount of oxygen available etc.

Using a 4 gas analyzer we tune the combustion process.  When the combustion process is most efficient, the engine is making best power. We tune for best power across the entire RPM and Load range.  We tune for Best power at cruise as well, and shoot for the leaner side of the scale. This yields very good fuel economy, cleaner combustion and power on tap.  

I am not saying EFI can't be tuned with AFR, it just isn't the way we do it.  

[Hoist!]

You are running 585s, Fatcat and no dip? I'm impressed.  Max

Not quite. I haven't finished that build yet. We'll see how she runs and tunes! I'll be sure to let youze know, and show ya the results!

Hoist!

[Hoist!]

The equipment we use to tune is different than most other tuners use.  Most (probably 99%) tune with AFR.  We don't use AFR for tuning, we can't see the AFR, have no way to measure AFR and don't adjust for AFR.

We use combustion science to tune the engine. When fuel is burned it is a chemical reaction. The chemical reaction gives off by products, these are the emissions. CO, CO2, HC and O2 are all emission in the exhaust gasses. AFR only looks at the O2, the least important in the equation. Carbon Monoxide, CO is partially burned fuel. Carbon Dioxide, CO2 is fully burned fuel. Hydrocarbons, HC is raw unburned fuel. Oxygen, O2 is left over that isn't used in the combustion process.  We look at the emissions in the exhaust gasses. The gas readings give us indications of how the timing is, if there is too much or to little fuel for the amount of oxygen available etc.

Using a 4 gas analyzer we tune the combustion process.  When the combustion process is most efficient, the engine is making best power. We tune for best power across the entire RPM and Load range.  We tune for Best power at cruise as well, and shoot for the leaner side of the scale. This yields very good fuel economy, cleaner combustion and power on tap.  

I am not saying EFI can't be tuned with AFR, it just isn't the way we do it.  

And as an HVAC Engineer, I understand this, fully agree, and why they do my tuning. I'm very happy with their results too. But I'd rather they speak on this since they tuned it. Thanks for the explanation for me (and the GREAT tune)!

Hoist!

[Twolanerider]

You are running 585s, Fatcat and no dip? I'm impressed.  Max

Not quite. I haven't finished that build yet. We'll see how she runs and tunes! I'll be sure to let youze know, and show ya the results!

Hoist!

Did Mike get the alignment tool off to you?

[Hoist!]

You are running 585s, Fatcat and no dip? I'm impressed.  Max

Not quite. I haven't finished that build yet. We'll see how she runs and tunes! I'll be sure to let youze know, and show ya the results!

Hoist!

Did Mike get the alignment tool off to you?

I called him today but hadn't heard back. He was supposed to ship it today, 2nd day shipment. Vern's expecting it on Wed. I'd like to be there for that, so he said he'd call me when he gets it. Thanks for your help on that one Don!!!

Hoist!

[skyhook]

and here's a cvo 110" with bathtub heads, 257 cam, supermeg, hpi t/b, big injectors, power commander, dj250...this chart is uncorrected, so subtract a few points compared to sae

pipes are kinda like cams...where do you want power?...i have a dyna and want my power 3500 to 6000...with 28 discs and open end cap it makes best hp, but tq suffers...can't have our cake and eat it, too!...size of the headpipe and baffle really affect the location of the powerband

[attachment removed after 60 days by system]

[Twolanerider]

I called him today but hadn't heard back. He was supposed to ship it today, 2nd day shipment. Vern's expecting it on Wed. I'd like to be there for that, so he said he'd call me when he gets it. Thanks for your help on that one Don!!!

Hoist!

That was an easy one.  No sweat.  I'm interested too in hearing what difference (if any) he finds between how any of us might have done it with string and straight edges versus what he'll see move with the alignment tool.  Don't know if I'd told but the old SERG was spot on.  I don't think the alignment tool moved anything a frog hair.  The SEEG was helped by its use though.  Not enough riding since to really know what difference that will make in the saddle. But it can't hurt.

[ejk_dyna]

Hoist -

When you talked about the "combustion effeciency tuning method" or however you said it...I thought you were going to say Joe had invented some new double secret method... .

Now I think you are talking about the fact that Factory Pro Dyno's (like Big Boyz) use a 4 gas EGA instead of O2 like dynojet...right?  The Factory Pro website kind of reminds me of RB Racing...they are smarter than everyone else and their competitors are dumb sh-t's 

[ederdelyi]

Before this goes "does too, does not":

Both methods can accomplish the same basic goals. In the hands of someone who truly knows what they are doing and what the equipment is capable of. One of the downsides to tuning with a gas analyzer is response time. O2 sensors have their quirks as well. I tuned with gas analyzer and EGT readings many times as well as with an O2 setup and was able to get equal results. It ain't the method, it's who is doing the tune and what they know that brings it all together.

We now take you back to regular programming. Play nice and don't hurt each other :>)

OBTW, dips are an indicator of VE, and as the intake/exhaust tune varies so will VE. VE is NOT constant in NA engines or "adder" engines either for that matter. The "dips" are there, the equipment being used to measure the output just may not have the resolution and response time to display them :>)

[Sc00ter]

You are running 585s, Fatcat and no dip? I'm impressed.  Max

My dyno printout is shown in reply #41...

Cycle Rama 595 cams and heads, Fatcat and no dip!

[Hoist!]

Hoist -

When you talked about the "combustion effeciency tuning method" or however you said it...I thought you were going to say Joe had invented some new double secret method... .

Now I think you are talking about the fact that Factory Pro Dyno's (like Big Boyz) use a 4 gas EGA instead of O2 like dynojet...right?  The Factory Pro website kind of reminds me of RB Racing...they are smarter than everyone else and their competitors are dumb sh-t's 

HeHe!!! OK? I flat out stated that Big Boyz used the Combustion Efiiciency method to tune my bike, and I believe in it. You guys love stirring the pot when it comes to tuning. Lemme guess? You have a shop and tune bikes too?

Hoist!

[ederdelyi]

Some of us just know that the wheel has not been re-invented. We've found ways to make it roll a little easier and make it to tighter tolerances, but the basic design is pretty much unchanged. A good tune is a good tune, doesn't really matter how one arrives at it. As stated in my previuos post, I've used both methods and each one has advantages and disadvantages. Neither method can eliminate the root problem(s) that cause changes in VE, only show the change and allow the tuner/builder to apply the knowledge and expertise required to address the problem. Fuel and timing alone will not be the answer to all problems. One can only attempt to maximize the use of the trapped mass that resulted from the cycle being addressed with fuel and timing adjustments.

EDIT: Don't read anything negative into this as far as individuals or methods. It's good to be enthusiastic and proud of your work. Giving an "attaboy" to those who helped you accomplish your goal is natural as well. Just remember that it can start to look like "advertising" very quickly. And no, I am not a shop owner or tuner. I don't sell anything, especially here.

[easyricer]

I'm running the S&S SPOs on my SE 95 Roadglide. With the Fatcat, I had great top end but lost some bottom end, with the modified stock pipes (BobVics Superflows) I got my bottom end back but lost the top. When I put the SPOs back on, I got both back. I love the sound and I love to power, and I'm pretty partial to the look of the wide mufflers too!
EASY

[Hoist!]

Some of us just know that the wheel has not been re-invented. We've found ways to make it roll a little easier and make it to tighter tolerances, but the basic design is pretty much unchanged. A good tune is a good tune, doesn't really matter how one arrives at it. As stated in my previuos post, I've used both methods and each one has advantages and disadvantages. Neither method can eliminate the root problem(s) that cause changes in VE, only show the change and allow the tuner/builder to apply the knowledge and expertise required to address the problem. Fuel and timing alone will not be the answer to all problems. One can only attempt to maximize the use of the trapped mass that resulted from the cycle being addressed with fuel and timing adjustments.

EDIT: Don't read anything negative into this as far as individuals or methods. It's good to be enthusiastic and proud of your work. Giving an "attaboy" to those who helped you accomplish your goal is natural as well. Just remember that it can start to look like "advertising" very quickly. And no, I am not a shop owner or tuner. I don't sell anything, especially here.

I was reffering to ej as a shop owner not you ed, but I could be wrong about that too! The pot stirrers usually have an agenda. I have none! And I will always praise those who do good work for me, and likewise, I'll let ya know when I think someone sucks too, if that was my experience with them! I don't read anything negative into it at all ed! I'm on the same page! Hey man, I LOVE my carb bikes which have never seen dynos EVER!!! Wow, what a concept, and they happen to run great too! I don't care what device you use, what dyno you use, what tuner you use! These bikes, like everything before this FI crap, need to be tuned! Just get er done!!! After all, this chit ain't ROCKET SCIENCE!!! But hey, I can stir the pot with the best of em! Lay down the ground rules, pull up to the line, and let's Rock and Roll!!!

Hoist!

[Hoist!]

I'm running the S&S SPOs on my SE 95 Roadglide. With the Fatcat, I had great top end but lost some bottom end, with the modified stock pipes (BobVics Superflows) I got my bottom end back but lost the top. When I put the SPOs back on, I got both back. I love the sound and I love to power, and I'm pretty partial to the look of the wide mufflers too!
EASY

I LOVED my SPO's on a stock motor, even a stock 110". But way too restrictive on performance builds. I wanted to keep mine after I redid my motor, but thru testing, I left WAY too much performance on the table with em! FatCats work well in performance applications, and they still have another option in the Borzilla for even bigger hi-po applications! D&D's got their chit together. This is the actually the first time I've seen so much anti FatCat sentiment. Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive? Just sayin!

Hoist!

[GoFast.....]

I'm running the S&S SPOs on my SE 95 Roadglide. With the Fatcat, I had great top end but lost some bottom end, with the modified stock pipes (BobVics Superflows) I got my bottom end back but lost the top. When I put the SPOs back on, I got both back. I love the sound and I love to power, and I'm pretty partial to the look of the wide mufflers too!
EASY

I LOVED my SPO's on a stock motor, even a stock 110". But way too restrictive on performance builds. I wanted to keep mine after I redid my motor, but thru testing, I left WAY too much performance on the table with em! FatCats work well in performance applications, and they still have another option in the Borzilla for even bigger hi-po applications! D&D's got their chit together. This is the actually the first time I've seen so much anti FatCat sentiment. Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive? Just sayin!

Hoist!

I do not think there is that much anti Fatcat feelings here. Look at the dyno section.There are plenty of Fatcats. I think we just tend to analyze everything and I do not think anyone will argue they are great at the top. The Big Fatcat dip is a well known issue

[Admiral Akbar]

"Hey man, I LOVE my carb bikes which have never seen dynos EVER!!! Wow, what a concept, and they happen to run great too! "

Well heck,,

Now I'm confused.. I've pretty much been a carb guy up until about a coupla months ago.. Bought an 02 RK classic with FI.. Thing was stage 1.. not sure it had any download.. It ran OK... Added a Tmax and it's so much eaiser to tune than the carbs. No emussion tube holes to add, no baffles on the main, no t-jets.  The thing tells you where your mixture is. All you got to do is play with the timing tables.. You need to do that with a carbed bike as well..  Not sure the bike ever needs to see a dyno cept for bragging rights...   and you don't even get gas on your hands.. Max.  

[Hoist!]

I'm running the S&S SPOs on my SE 95 Roadglide. With the Fatcat, I had great top end but lost some bottom end, with the modified stock pipes (BobVics Superflows) I got my bottom end back but lost the top. When I put the SPOs back on, I got both back. I love the sound and I love to power, and I'm pretty partial to the look of the wide mufflers too!
EASY

I LOVED my SPO's on a stock motor, even a stock 110". But way too restrictive on performance builds. I wanted to keep mine after I redid my motor, but thru testing, I left WAY too much performance on the table with em! FatCats work well in performance applications, and they still have another option in the Borzilla for even bigger hi-po applications! D&D's got their chit together. This is the actually the first time I've seen so much anti FatCat sentiment. Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive? Just sayin!

Hoist!

I do not think there is that much anti Fatcat feelings here. Look at the dyno section.There are plenty of Fatcats. I think we just tend to anylize everything and I do not think anyone will argue they are not great at the top. The big Fatcat dip is a well known issue

Just tryin to get stiuated here Go Fast! Thanks for the clarification. I tend not to try to nit pick or tear things aparts. I either like something or I don't. If I like it, I'll tell ya that. If I hate it, I'll tell ya that too. So far I've been responding to things and catching up on this wonderful site. Just like the parts though, people here prolly will either like me or hate me too after awhile!!! I hope it's the latter though!!!

Hoist!

[Hoist!]

"Hey man, I LOVE my carb bikes which have never seen dynos EVER!!! Wow, what a concept, and they happen to run great too! "

Well heck,,

Now I'm confused.. I've pretty much been a carb guy up until about a coupla months ago.. Bought an 02 RK classic with FI.. Thing was stage 1.. not sure it had any download.. It ran OK... Added a Tmax and it's so much eaiser to tune than the carbs. No emussion tube holes to add, no baffles on the main, no t-jets.  The thing tells you where your mixture is. All you got to do is play with the timing tables.. You need to do that with a carbed bike as well..  Not sure the bike ever needs to see a dyno cept for bragging rights...   and you don't even get gas on your hands.. Max.  

I will not debate the TMax with you man. Sorry. Like I said above, that's me man! And I'm not a Zipper's fan at all! Please leave that one alone!

Hoist!

[ederdelyi]

>>Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive?<<

I think you'll find that this is generally a good group with a large cross section of experience and knowledge. Most don't take things at face value, and when their own experience or knowledge differs from yours you can expect to hear about it :>) Anti-Fatcat? Nah, I don't think some dislike it any more than I dislike T-headers :>)

[GoFast.....]

"Hey man, I LOVE my carb bikes which have never seen dynos EVER!!! Wow, what a concept, and they happen to run great too! "

Well heck,,

Now I'm confused.. I've pretty much been a carb guy up until about a coupla months ago.. Bought an 02 RK classic with FI.. Thing was stage 1.. not sure it had any download.. It ran OK... Added a Tmax and it's so much eaiser to tune than the carbs. No emussion tube holes to add, no baffles on the main, no t-jets.  The thing tells you where your mixture is. All you got to do is play with the timing tables.. You need to do that with a carbed bike as well..  Not sure the bike ever needs to see a dyno cept for bragging rights...   and you don't even get gas on your hands.. Max.  

Couldn't agree more. A tmax FI does not need to ever see a dyno if thats what you want and adjusting fuel and timing is a key board and click away and no changeing jets at higher or lower elevations. Its doing it will you ride.

[Hoist!]

>>Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive?<<

I think you'll find that this is generally a good group with a large cross section of experience and knowledge. Most don't take things at face value, and when their own experience or knowledge differs from yours you can expect to hear about it :>) Anti-Fatcat? Nah, I don't think some dislike it any more than I dislike T-headers :>)

Certainly fair enough ed! Just tryin to understand the rules of engagement!

Hoist!

[Sc00ter]

I'm running the S&S SPOs on my SE 95 Roadglide. With the Fatcat, I had great top end but lost some bottom end, with the modified stock pipes (BobVics Superflows) I got my bottom end back but lost the top. When I put the SPOs back on, I got both back. I love the sound and I love to power, and I'm pretty partial to the look of the wide mufflers too!
EASY

I LOVED my SPO's on a stock motor, even a stock 110". But way too restrictive on performance builds. I wanted to keep mine after I redid my motor, but thru testing, I left WAY too much performance on the table with em! FatCats work well in performance applications, and they still have another option in the Borzilla for even bigger hi-po applications! D&D's got their chit together. This is the actually the first time I've seen so much anti FatCat sentiment. Or are most things about tearing things apart here? Either that, or you guys get too many BS'ers here, and must stay on the defensive? Just sayin!

Hoist!

I do not think there is that much anti Fatcat feelings here. Look at the dyno section.There are plenty of Fatcats. I think we just tend to analyze everything and I do not think anyone will argue they are great at the top. The Big Fatcat dip is a well known issue

hehe...  Here it is again...  Fatcat with Quiet Performance Baffle - no Dip!   

[attachment removed after 60 days by system]

[ederdelyi]

Sc00ter ... it's not just the pipe, it's how well it matches up with the rest of the build. All intake/exhaust combos have the potential to produce flucuations in the power curve when combined with certain other components such as cams and heads. If ya got a good match ... COOL!

[Sc00ter]

Sc00ter ... it's not just the pipe, it's how well it matches up with the rest of the build. All intake/exhaust combos have the potential to produce flucuations in the power curve when combined with certain other components such as cams and heads. If ya got a good match ... COOL!

Yep, I know...  That's what I have been trying to say all along...  If the Fatcat is applied in combination with the overall package, there is no dip!  With the right combination of parts, it's a hell-of-a pipe!   

[Admiral Akbar]

"Heck most 2 into 1 seem to loose low end but pick up on peak TQ.."

Scooter,

Maybe I should have qualified this. This is a common problem.. It's generally related to the system having to much flow on the low end.. It can be corrected.. As in your case.. In your case the pipe is not stock and it's on a larger motor.. Both items help the low end while giving up potential on the high end.  I was talking in general terms and at the time the displacement was unknown.  Do I think that 2 into 1s suck, heck no.. 2 of the bikes I own have them.. One is the only good looking Fatcat that DnD makes and the other is a Bassani.. Stuff a FC on a 95 with a stock baffle and you can get the dip.. As Ed says you got a good match..

Max

[Hoist!]

"Heck most 2 into 1 seem to loose low end but pick up on peak TQ.."

Scooter,

Maybe I should have qualified this. This is a common problem.. It's generally related to the system having to much flow on the low end.. It can be corrected.. As in your case.. In your case the pipe is not stock and it's on a larger motor.. Both items help the low end while giving up potential on the high end.  I was talking in general terms and at the time the displacement was unknown.  Do I think that 2 into 1s suck, heck no.. 2 of the bikes I own have them.. One is the only good looking Fatcat that DnD makes and the other is a Bassani.. Stuff a FC on a 95 with a stock baffle and you can get the dip.. As Ed says you got a good match..

Max

Right on man! It's all about the RIGHT combination and matching your components! Always has been, and always will be!!! And like I've always said, this chit ain't ROCKET SCIENCE either!!!

Hoist!

[Sc00ter]

"Heck most 2 into 1 seem to loose low end but pick up on peak TQ.."

Scooter,

Maybe I should have qualified this. This is a common problem.. It's generally related to the system having to much flow on the low end.. It can be corrected.. As in your case.. In your case the pipe is not stock and it's on a larger motor.. Both items help the low end while giving up potential on the high end.  I was talking in general terms and at the time the displacement was unknown.  Do I think that 2 into 1s suck, heck no.. 2 of the bikes I own have them.. One is the only good looking Fatcat that DnD makes and the other is a Bassani.. Stuff a FC on a 95 with a stock baffle and you can get the dip.. As Ed says you got a good match..

Max

Yep, I got a good match - and not by accident!  

I just get a kick out of those who bolt a particular part on some random combination of parts and then label it as "this" or "that" - whether it is pipes, cams, throttle bodies or some other piece of the equation.  It is the total package that gets you there - a properly applied combination of pieces.  Many parts that are "labeled" as having a particular issue perform just fine when properly applied.  

Some would (and have) comment that my 62mm HPI throttle body is to large for the application - and yet - I have great performance and great fuel mileage.  The throttle body fits the rest of the combination of parts very well - and also not by accident...  I often hear perfectly good cams or pipes or throttle bodies critized or labeled as one thing or another by the "talking about it" crowd - when the "doing it" crowd can apply those very same parts with fine results.

Just trying to make a point and having some fun!  

[Hoist!]

"Heck most 2 into 1 seem to loose low end but pick up on peak TQ.."

Scooter,

Maybe I should have qualified this. This is a common problem.. It's generally related to the system having to much flow on the low end.. It can be corrected.. As in your case.. In your case the pipe is not stock and it's on a larger motor.. Both items help the low end while giving up potential on the high end.  I was talking in general terms and at the time the displacement was unknown.  Do I think that 2 into 1s suck, heck no.. 2 of the bikes I own have them.. One is the only good looking Fatcat that DnD makes and the other is a Bassani.. Stuff a FC on a 95 with a stock baffle and you can get the dip.. As Ed says you got a good match..

Max

Yep, I got a good match - and not by accident!  

I just get a kick out of those who bolt a particular part on some random combination of parts and then label it as "this" or "that" - whether it is pipes, cams, throttle bodies or some other piece of the equation.  It is the total package that gets you there - a properly applied combination of pieces.  Many parts that are "labeled" as having a particular issue perform just fine when properly applied.  

Some would (and have) comment that my 62mm HPI throttle body is to large for the application - and yet - I have great performance and great fuel mileage.  The throttle body fits the rest of the combination of parts very well - and also not by accident...  I often hear perfectly good cams or pipes or throttle bodies critized or labeled as one thing or another by the "talking about it" crowd - when the "doing it" crowd can apply those very same parts with fine results.

Just trying to make a point and having some fun!  

HeHe!!! Your welcome for the free testing Scott!!!

Hoist!

[Sc00ter]

"Heck most 2 into 1 seem to loose low end but pick up on peak TQ.."

Scooter,

Maybe I should have qualified this. This is a common problem.. It's generally related to the system having to much flow on the low end.. It can be corrected.. As in your case.. In your case the pipe is not stock and it's on a larger motor.. Both items help the low end while giving up potential on the high end.  I was talking in general terms and at the time the displacement was unknown.  Do I think that 2 into 1s suck, heck no.. 2 of the bikes I own have them.. One is the only good looking Fatcat that DnD makes and the other is a Bassani.. Stuff a FC on a 95 with a stock baffle and you can get the dip.. As Ed says you got a good match..

Max

Yep, I got a good match - and not by accident!  

I just get a kick out of those who bolt a particular part on some random combination of parts and then label it as "this" or "that" - whether it is pipes, cams, throttle bodies or some other piece of the equation.  It is the total package that gets you there - a properly applied combination of pieces.  Many parts that are "labeled" as having a particular issue perform just fine when properly applied.  

Some would (and have) comment that my 62mm HPI throttle body is to large for the application - and yet - I have great performance and great fuel mileage.  The throttle body fits the rest of the combination of parts very well - and also not by accident...  I often hear perfectly good cams or pipes or throttle bodies critized or labeled as one thing or another by the "talking about it" crowd - when the "doing it" crowd can apply those very same parts with fine results.

Just trying to make a point and having some fun!  

HeHe!!! Your welcome for the free testing Scott!!!

Hoist!

What's next?   

[Don D]

Many parts that are "labeled" as having a particular issue perform just fine when properly applied.  

Very good point!

Personally I read a lot of these forums and look for trends. That way these is an element of probability to the proposed combination.

The posts that kill me are titled "the best ...."

Oh come on it is all about constraints and combination of parts.

[Sc00ter]

Many parts that are "labeled" as having a particular issue perform just fine when properly applied.  

Very good point!

Personally I read a lot of these forums and look for trends. That way these is an element of probability to the proposed combination.

The posts that kill me are titled "the best ...."

Oh come on it is all about constraints and combination of parts.

and donuts! 

[ederdelyi]

>>What's next?<<

Active intake/exhaust tuning, VVT ... lots that hasn't even been touched yet. Oh, I forgot, we aren't talking rocket science here, just putting a pearl necklace on a dinosaur :>)  

[Sc00ter]

[
Oh come on it is all about constraints and combination of parts.

and donuts! 

No donuts here.
Just a good running 110 that has the right combination of parts.
58mm TBW Harley T/B in and a Fatcat out.
But I do like the donut holes!


[/quote]

Do you "dip" your donuts?  Just wondering?

[Spiderman]

[
Oh come on it is all about constraints and combination of parts.

and donuts! 

No donuts here.
Just a good running 110 that has the right combination of parts.
58mm TBW Harley T/B in and a Fatcat out.
But I do like the donut holes!

Do you "dip" your donuts?  Just wondering?
[/quote]


Plain, no dipping.
I'm a purist.

[ejk_dyna]

spiderman - what type of bike - bagger, softail or dyna?

[Twolanerider]

No donuts here.
Just a good running 110 that has the right combination of parts.
58mm TBW Harley T/B in and a Fatcat out.
But I do like the donut holes!

Cool dyno chart.  How often does it break and where's the JATO mounted.

[Don D]

Spider
So what is between the pipe and the TB? Parts combination? TIA

[ejk_dyna]

<<HeHe!!! OK? I flat out stated that Big Boyz used the Combustion Efiiciency method to tune my bike, and I believe in it. You guys love stirring the pot when it comes to tuning. Lemme guess? You have a shop and tune bikes too?>>

No not really stirring the pot.  I read your posts too quickly and thought you were talking about a tuning method you used generally.  Did not catch the Big Boyz connection.  Then when Springer posted I remembered Factory pro uses EGA not AFR.  No don't have a shop...just a gearhead who works out of my garage...like lots of people here.  Done a lot of builds for friends...and friends of friends...and cousins of a friend of a friend...LOL.

And I like the Fatcat.  I have a Fatcat and a Bassani Road Rage and a White Bros E-Pipe and 2" CS tapers...all for my dyna.

[Hoist!]

<<HeHe!!! OK? I flat out stated that Big Boyz used the Combustion Efiiciency method to tune my bike, and I believe in it. You guys love stirring the pot when it comes to tuning. Lemme guess? You have a shop and tune bikes too?>>

No not really stirring the pot.  I read your posts too quickly and thought you were talking about a tuning method you used generally.  Did not catch the Big Boyz connection.  Then when Springer posted I remembered Factory pro uses EGA not AFR.  No don't have a shop...just a gearhead who works out of my garage...like lots of people here.  Done a lot of builds for friends...and friends of friends...and cousins of a friend of a friend...LOL.

And I like the Fatcat.  I have a Fatcat and a Bassani Road Rage and a White Bros E-Pipe and 2" CS tapers...all for my dyna.

It's all good here man! We're all after the same thing! Passion drives us and we want to know who's who and who's FOS!!! Thanks for that reply ej!

Hoist!

[Spiderman]

spiderman - what type of bike - bagger, softail or dyna?

Bagger!

[fuzznut5197]

>>What's next?<<

Active intake/exhaust tuning, VVT ... lots that hasn't even been touched yet. Oh, I forgot, we aren't talking rocket science here, just putting a pearl necklace on a dinosaur :>)  

You pot stirrer you. 

Active exhaust, hmm. The metrics use a servo, but they have a big rpm window to cover. A H-D's diesel-like rpm window could probably get away with just a butterfly valve and a solenoid.

While I appreciate a good exhaust shootout, I would think that the results are only truly valid for the engine that did the tests. Everyone else- YMMV. I would like to see some data where you look past the chrome and focus on the design. There are so many collector designs (da muffler part  ) that mess up the primary wave tuning, gathering and applying data might be an exercise in futility, so.. back to cut & try!! 

Am I stirring an empty pot? 

[Don D]

with just a butterfly valve and a solenoid.

HDI and Buell are already there and the exhaust is tied to the ECU for control.

[fuzznut5197]

with just a butterfly valve and a solenoid.

HDI and Buell are already there and the exhaust is tied to the ECU for control.

I saw the Buell patent, thought it was a servo but yeah, it switches between 2 differently tuned chambers to minimize the midrange torque dip. The HDI I thought was for noise control purposes.

Hey Don, I would like to roll my own 2-1, what do you think, 1 7/8" or 2" primaries?

[Twolanerider]

with just a butterfly valve and a solenoid.

HDI and Buell are already there and the exhaust is tied to the ECU for control.

I saw the Buell patent, thought it was a servo but yeah, it switches between 2 differently tuned chambers to minimize the midrange torque dip. The HDI I thought was for noise control purposes.

Hey Don, I would like to roll my own 2-1, what do you think, 1 7/8" or 2" primaries?

Don't know what's in front of the pipes or intended riding styles well enough to make a suggestion.  But.....   Last time I saw John Golden (Rolling Thunder Dyno) he had as an intended winter project creating a new set of pipes for baggers.  Had a mftr lined up for when the effort was complete.  John is pretty proficient where producing power is concerned.  He hoped to have at least a prototype done by spring sometime.  So any interest in as yet unpurchased new pipes might be worth sending him a message to ask "what's up?".

[Don D]

Right you are about the HDI stuff but with a little tinkering.......

I think the 1 7/8" would be the best for you. Burns Stainless does offer some design help if you need that, I think. Would really be nice if Rich Products would get the big motor TH done.

[PanHeadRed]

>Cycle shack makes a stagger dual for baggers that are equal lenght.. But no on seem to run them..<

I ran them. 

[fuzznut5197]

Twolanerider, I have a Dyna, (the HTT pic). I adjusted the pic to reflect what Don's headwork will do to my bike. 

Don, that's good, I was running a 1 7/8" boarzilla primary for a couple of weeks last fall. I got it *real* cheap, but it's for a softail, and I would need a I-beam to support the muffler from the tranny, as it would be so far back. I'm afraid to shorten it, and ruin the tuned lengths, but maybe I'll cave in and do it anyway. 

Would really be nice if Rich Products would get the big motor TH done.

That would be awesome!!

[ederdelyi]

>>I ran them<<

Did ya win? Oh, you likely meant you used them --- DUH, too much street racing :>)

Fuzz,
I don't know how deep you want to get into designing exhaust, but there is some info in Dennish's V-Twin series, A.Graham Bell's "Four Stroke Performance Tuning", Smith and Morrison "Scientific Design of Intake & Exhaust Systems" as well as both Burns and Flowmaster have design software available. Burns will run some calcs for you if you purchase one of their collectors or other pieces to build a system. I used both Dynomation and Engine Analyzer Pro to do  "what if's" and then test the prototypes on the dyno. One hint: Make things longer than you think you need and trim as needed for best tune, 'cuz even the best simulation will likely be off even after you refine the model with real world data feedback. Once you get the head pipe/collector done, the "can" is mostly about volume and contributes little if any to the overall result.

Good luck with it if you decide to take it on, it can be fun and rewarding as well.

EDIT: I thought that Burns was offering their X-Design package, but it appears that is not true. They do offer design service using their X-Design software and have a form you can fill out on their website. I do know of some sources for "affordable" design software if you are interested. Flowmaster is high end and geared to automotive but can be adapted to most anything if one wishes to put in the time and effort.

[Reddog74usa]

Wow, Thanks for all the replies but I think I'll just do as Max said and keep my Bassani Road Rage   

[ederdelyi]

Seems we might need an "Earl" equivalent for exhaust discussions :>) I can hear the wheels turning and the gears meshing out there right now ...

[Faast Ed]

Shoot, I have not even seen Earl in a while. I sure hope that he's okay,.....

[lee]

He's well.

[attachment removed after 60 days by system]

[fuzznut5197]

Fuzz, I don't know how deep you want to get into designing exhaust,

Right now, I'm deeper than I ever wanted to go. Curiosity does that. For a component that can kill 20ft/lbs of torque and 10hp in a hearbeat, I just wanted to know why. You know, why does pipe A work better than pipe B and C on this motor, but not as good as pipe B and C on this other motor? I just wanted the Pop Mech version of what's going on. Actually Ed, this is all your fault, with your "sometimes off the shelf solutions don't work" comment in a post several years ago. Be careful what you write, somebody might learn something.  

"Scientific Design of Intake & Exhaust Systems"

Got it, boy is it dated! But the fundamentals of wave tuning are there, so it's a good read.

both Burns and Flowmaster have design software available

Yeah but I would think that they would be good for race-only situations. Unless they have specific sound attenuation models for street pipes.

I used both Dynomation and Engine Analyzer Pro to do  "what if's" and then test the prototypes on the dyno.

I had played with EAP for a bit, then the demo expired.  No 315/405 exhaust simulation going on there. And since a Haley 2-1 muffler is the collector, how do you simulate that?

Once you get the head pipe/collector done, the "can" is mostly about volume and contributes little if any to the overall result.

Yeah but on a H-D, the can is the collector. By what you're saying, I should be able to remove the muffler from any 2-1 exhaust, and still have the same power curves. If I plug some specs into pipemax for a hp peak at say 5,700, I'll get like 37-40" primary and 20" collector length.  What, 20" of collector pipe andthen the can? Where am I going to put that? No problem under a car but...
I guess what I'm saying is, when the collector has to do double duty as a muffler too, on a weird fire V2, normal calculations get "icky".

Ahh, headache  

[ederdelyi]

>>I had played with EAP for a bit, then the demo expired.   No 315/405 exhaust simulation going on there. And since a Haley 2-1 muffler is the collector, how do you simulate that?<<

As shipped, that's somewhat true. That's where refining the model comes into play. And, the collector is not the "can" Take a closer look. Where the pipes merge, and in fact, any point where a diameter or pressure change can occur becomes a tune point. That short piece the "can" mounts to is the collector. The "can" needs to have the volume to allow the gases to expand and exit the system with low restriction and to house the baffle needed to attenuate the noise. Contrary to popular belief, the exhaust does not flow thru the attenuation material in a properly designed baffle, only sound waves. The final tune point can be the can's exit, but it's effect on overall tune is small in comparison to the length/diameter of the primaries and the collector. A reverse megaphone is a good example of end exit tuning. Supertrapp discs are another. Besides changing backpressure (which is what you don't want) they alter the tune point slightly by changing the opening to the pressure differential between the gases exiting and the atmosphere ... that alters the reflected wave and it may be a different harmonic then the one the primaries and collector are tuned to and usually is.

Packaging an efficient system for a motorcycle is not easy for lots of reasons. That is one of the drawbacks to many of the existing tools out there as they are not MC specific and require some "tweaking" to be of use.

Sheesh, buy 'em books and they eat the damn pages :>)

[Admiral Akbar]

"that alters the reflected wave and it may be a different harmonic the the one the primaries and collector are tuned to and usually is."

I figure that was the way 2 into 1 have the potential fore making a broader power band than a 2 into 2.. 2 into 2 with stepped head pipes do the same thing except the tq peak is not as high.. Max

[ederdelyi]

Max gets it. Tuning the exhaust is all about timing the negative pressure waves to arrive at the right time in the overlap period. The trick is to spread that timing over the greatest range of RPM and with sufficient amplitude to be of use.

[fuzznut5197]

Haha Ed, I read your post last night and am still trying to absorb it.    But anyway:

And, the collector is not the "can"

Yes I know, when you said "can" I immediately thought sportbike canister.

Where the pipes merge, and in fact, any point where a diameter or pressure change can occur becomes a tune point. That short piece the "can" mounts to is the collector

This is where my error was. I was thinking "collector" in terms of collector+extension. For example, the RB pro stock pipe. I was jumping ahead and adding secondary tuning effects, where the wave from the extension "assists" the specific primary low pressure wave that's going to arrive at overlap. From what I understand, it only affects torque on the left side of the torque peak.

But yeah, what's going on when we just look at the primaries and collector? Why do we get more midrange torque when we join the 2 primaries with a collector? Is it the tuning waves or is it the effect of mass flow? Is the exiting gas mass from the active primary pulling the other cylinder's primary below atmosphere, assisting the flow when the other cyl's exhaust valve opens?

The final tune point can be the can's exit, but it's effect on overall tune is small in comparison to the length/diameter of the primaries and the collector.

I sorta agree with that, but we're talking street H-D here. What's connected to a H-D 2-1 collector has a HUGE effect on 50% of the power band. Drag racers don't care, they got their 2-1 with collector and stub, or maybe an open megaphone to give the tuned point a little more bandwidth. But they could care less that their motor is dead below 4,500rpm. When we talk about a street 2-1, things get a little blurry. The goal is to "gussy up" the left side of the torque curve as much as you can, without messing up what you've established with the primary pipe tuning. I know, you can't have it all. 

Besides changing backpressure (which is what you don't want)

I might want a little backpressure, since there is no room for a proper size exhaust on my bike.
On a car, no problem, plenty of room to have a zero backpressure exhaust and full muffler system. Even a sport bike has room, the tuned length requirements for a 12Krpm are a lot shorter. Backpressure bites, because you are surely going to rob Barney to pay Fred, but it might be useful to "make the torque curve look pretty". This is where an active exhaust would be really cool!!! Prop up the low end with a little backpressure, and then let 'er rip unobstructed until redline!

they alter the tune point slightly by changing the opening to the pressure differential between the gases exiting and the atmosphere ... that alters the reflected wave and it may be a different harmonic then  the one the primaries and collector are tuned to and usually is.

See, this is where the confusion lies, and I have an example. A while ago there was a post on the old HTT, the guy had a crate 124" and a RB 124 challenge pipe. The tuner thought the numbers could be better, so he stuck either a thunderheader or supertrapp collector at the end of the RB pipe. The engine gained 10-12hp and like 20ft/lbs of torque. WTF! The RB pipe was designed for that specific motor, to get as much hp as possible for drag racing. Sticking things at the end of it should kill horsepower, not add to it! I have an idea, but what do you think?

Sheesh, buy 'em books and they eat the damn pages :>)

That explains the stomach ache... 

[GoFast.....]

Haha Ed, I read your post last night and am still trying to absorb it.    But anyway:

And, the collector is not the "can"

Yes I know, when you said "can" I immediately thought sportbike canister.

Where the pipes merge, and in fact, any point where a diameter or pressure change can occur becomes a tune point. That short piece the "can" mounts to is the collector

This is where my error was. I was thinking "collector" in terms of collector+extension. For example, the RB pro stock pipe. I was jumping ahead and adding secondary tuning effects, where the wave from the extension "assists" the specific primary low pressure wave that's going to arrive at overlap. From what I understand, it only affects torque on the left side of the torque peak.

But yeah, what's going on when we just look at the primaries and collector? Why do we get more midrange torque when we join the 2 primaries with a collector? Is it the tuning waves or is it the effect of mass flow? Is the exiting gas mass from the active primary pulling the other cylinder's primary below atmosphere, assisting the flow when the other cyl's exhaust valve opens?

The final tune point can be the can's exit, but it's effect on overall tune is small in comparison to the length/diameter of the primaries and the collector.

I sorta agree with that, but we're talking street H-D here. What's connected to a H-D 2-1 collector has a HUGE effect on 50% of the power band. Drag racers don't care, they got their 2-1 with collector and stub, or maybe an open megaphone to give the tuned point a little more bandwidth. But they could care less that their motor is dead below 4,500rpm. When we talk about a street 2-1, things get a little blurry. The goal is to "gussy up" the left side of the torque curve as much as you can, without messing up what you've established with the primary pipe tuning. I know, you can't have it all. 

Besides changing backpressure (which is what you don't want)

I might want a little backpressure, since there is no room for a proper size exhaust on my bike.
On a car, no problem, plenty of room to have a zero backpressure exhaust and full muffler system. Even a sport bike has room, the tuned length requirements for a 12Krpm are a lot shorter. Backpressure bites, because you are surely going to rob Barney to pay Fred, but it might be useful to "make the torque curve look pretty". This is where an active exhaust would be really cool!!! Prop up the low end with a little backpressure, and then let 'er rip unobstructed until redline!

they alter the tune point slightly by changing the opening to the pressure differential between the gases exiting and the atmosphere ... that alters the reflected wave and it may be a different harmonic then  the one the primaries and collector are tuned to and usually is.

See, this is where the confusion lies, and I have an example. A while ago there was a post on the old HTT, the guy had a crate 124" and a RB 124 challenge pipe. The tuner thought the numbers could be better, so he stuck either a thunderheader or supertrapp collector at the end of the RB pipe. The engine gained 10-12hp and like 20ft/lbs of torque. WTF! The RB pipe was designed for that specific motor, to get as much hp as possible for drag racing. Sticking things at the end of it should kill horsepower, not add to it! I have an idea, but what do you think?

Sheesh, buy 'em books and they eat the damn pages :>)

That explains the stomach ache... 

The gain in Hp suprises me but each engine has its own flow charaistics and that is a example of the populaity that is growing with the supertrapp. I wish you knew which one it was. He would have had to cut the thunderheader in half or use one dual slip ons

[ederdelyi]

>>But yeah, what's going on when we just look at the primaries and collector? Why do we get more midrange torque when we join the 2 primaries with a collector? Is it the tuning waves or is it the effect of mass flow? Is the exiting gas mass from the active primary pulling the other cylinder's primary below atmosphere, assisting the flow when the other cyl's exhaust valve opens?<<

The collector, if designed properly, should allow the other cylinder(s) exhaust pulse(s) to add to the negative going pulse(s) of the primary wave(s) generated by the other cylinder(s). Just like primary tuning, this effect has a limited range over which it is effective. As you know, there are both positive and negative going pressure waves in the system. For what we are trying to accomplish here we want the the negative going pulse with the largest amplitude to arrive at the cylinder of interest at the right time in the overlap cycle. On a low RPM motor and especially one in a motorcycle it may not be possible to use the 2nd (and strongest) pulse due to the length required for the primary and collector. Use of the 3rd, 4th, and even 5th pulse is often used to keep the size of the system to reasonable size. Also, many tend to forget that there are positive going pulses in the system and those are counter productive for our purpose. So what happens when the timing is off and/or those positive pulses arrive during overlap? We get things commonly referred to as TQ dips, reversion, being off the cam, etc. By the same token, we can get things like like over scavenging, short circuit losses, and so forth if the negative going pulse arrives at the wrong time or amplitude to assist cylinder fill to the optimum. Lots of stuff going on in there, it ain't like yer toilet flushing a ...


>> might want a little backpressure, since there is no room for a proper size exhaust on my bike.
On a car, no problem, plenty of room to have a zero backpressure exhaust and full muffler system. Even a sport bike has room, the tuned length requirements for a 12Krpm are a lot shorter. Backpressure bites, because you are surely going to rob Barney to pay Fred, but it might be useful to "make the torque curve look pretty". This is where an active exhaust would be really cool!!! Prop up the low end with a little backpressure, and then let 'er rip unobstructed until redline!<<

Actually, active exhaust works on the principle of altering the effective length of the system and thus altering the tune point(s) to a lower or higher RPM as the case may be. Backpressure is a no no, it's a parastitic loss that costs you power. For a street driven vehicle (that won't attract the LEO or piss off yer neighbors) the trick is to come up with a system that has the lowest possible noise, backpressure, and best overall performance that will fit in the physical constraints and look good ... piece of cake, right?

>>See, this is where the confusion lies, and I have an example. A while ago there was a post on the old HTT, the guy had a crate 124" and a RB 124 challenge pipe. The tuner thought the numbers could be better, so he stuck either a thunderheader or supertrapp collector at the end of the RB pipe. The engine gained 10-12hp and like 20ft/lbs of torque. WTF! The RB pipe was designed for that specific motor, to get as much hp as possible for drag racing. Sticking things at the end of it should kill horsepower, not add to it! I have an idea, but what do you think?<<

Where did it add power? What did it do the the shape of the curve? Hard to say without a lot more info, but I don't doubt that it's possible. Sometimes making a change like that can alter the system to make use of 2nd vs 3rd wave tunig or add a tuning element not considered in the original design. When I was doing a lot of intake and exhaust prototype work I woulld make primaries, runners, and even plenums with adjustable pieces and move things around to find the best possible combination. It was very interesting to see how things would interact and the effect on the power curve at diffeent RPMs.

It's a complex subject. Modeling/simulation is getting more sophisticated and lots more is being discovered as the search for increased efficiency, economy, and reduced emissions continues. Some of the high end stuff in use by the big boys that I have seen is mind boggling ... most likely beyond most of our budgets.

EDIT: So, now you likely have a headache and a pain in the a$$ to go with that stomach ache, eh? :>)

[fuzznut5197]

The collector, if designed properly, should allow the other cylinder(s) exhaust pulse(s) to add to the negative going pulse(s) of the primary wave(s) generated by the other cylinder(s). Just like primary tuning, this effect has a limited range over which it is effective. As you know, there are both positive and negative going pressure waves in the system. For what we are trying to accomplish here we want the the negative going pulse with the largest amplitude to arrive at the cylinder of interest at the right time in the overlap cycle. On a low RPM motor and especially one in a motorcycle it may not be possible to use the 2nd (and strongest) pulse due to the length required for the primary and collector. Use of the 3rd, 4th, and even 5th pulse is often used to keep the size of the system to reasonable size. Also, many tend to forget that there are positive going pulses in the system and those are counter productive for our purpose. So what happens when the timing is off and/or those positive pulses arrive during overlap? We get things commonly referred to as TQ dips, reversion, being off the cam, etc. By the same token, we can get things like like over scavenging, short circuit losses, and so forth if the negative going pulse arrives at the wrong time or amplitude to assist cylinder fill to the optimum. Lots of stuff going on in there, it ain't like yer toilet flushing a ...

Thanks Ed. I'm slowly getting a better understanding of what's going on. I think 

Actually, active exhaust works on the principle of altering the effective length of the system and thus altering the tune point(s) to a lower or higher RPM as the case may be. Backpressure is a no no, it's a parastitic loss that costs you power. For a street driven vehicle (that won't attract the LEO or piss off yer neighbors) the trick is to come up with a system that has the lowest possible noise, backpressure, and best overall performance that will fit in the physical constraints and look good ... piece of cake, right?

I know the Buell uses 2 separately tuned chambers, but with regards to backpressure I was just going with what I had read. Here:

"The exhaust ultimate power valve (EXUP) is a device fitted to selected Yamaha motorcycles (FZR, YZF, XV1900, R series) that constantly adjusts the back pressure within the collector of the exhaust system to enhance pressure wave formation as a function of engine speed. This ensures good low to mid-range performance.

At low engine speeds the wave pressure within the pipe network is low. A full oscillation of the Helmholtz resonance occurs before the exhaust valve is closed, and to increase low-speed torque, large amplitude exhaust pressure waves are artificially induced. This is achieved by partial closing of an internal valve within the exhaust â€" the EXUP valve â€" at the point where the four primary pipes from the cylinders join. This junction point essentially behaves as an artificial atmosphere. The alteration of the pressure at this point controls the behavior of reflected waves at this sudden increase in area discontinuity. Closing the valve increases the local pressure, inducing the formation of larger amplitude negative reflected expansion waves. A servo motor controlled by the ECU opens and shuts the valve. The EXUP valve operation goes from being almost fully closed at idle speed, through to being fully open at 9000 to 11000 RPM (2500 RPM for XV1900)."

Where did it add power? What did it do the the shape of the curve? Hard to say without a lot more info, but I don't doubt that it's possible. Sometimes making a change like that can alter the system to make use of 2nd vs 3rd wave tunig or add a tuning element not considered in the original design. When I was doing a lot of intake and exhaust prototype work I woulld make primaries, runners, and even plenums with adjustable pieces and move things around to find the best possible combination.

I don't know, never saw a dyno sheet. But the pipe was made specifically for the 124 challenge class, which allows SA/B2 heads and 675 cam. So I doubt the pipe was designed on a "crate" motor.

It was very interesting to see how things would interact and the effect on the power curve at different RPMs.

Yeah, it would be cool to do the dyno shootout where you run the header only and then the full system, just to see! GoFast... how much money ya got? 

It's a complex subject. Modeling/simulation is getting more sophisticated and lots more is being discovered as the search for increased efficiency, economy, and reduced emissions continues. Some of the high end stuff in use by the big boys that I have seen is mind boggling ... most likely beyond most of our budgets.

Tell them boys to hurry up before the only H-D I can buy is an electric one. I don't fell like rewinding armatures for more power just yet... 

[ederdelyi]

>>At low engine speeds the wave pressure within the pipe network is low. A full oscillation of the Helmholtz resonance occurs before the exhaust valve is closed, and to increase low-speed torque, large amplitude exhaust pressure waves are artificially induced. This is achieved by partial closing of an internal valve within the exhaust â€" the EXUP valve â€" at the point where the four primary pipes from the cylinders join. This junction point essentially behaves as an artificial atmosphere. The alteration of the pressure at this point controls the behavior of reflected waves at this sudden increase in area discontinuity. Closing the valve increases the local pressure, inducing the formation of larger amplitude negative reflected expansion waves. A servo motor controlled by the ECU opens and shuts the valve. The EXUP valve operation goes from being almost fully closed at idle speed, through to being fully open at 9000 to 11000 RPM (2500 RPM for XV1900)."<<

AYuupp :>) The use of the term backpressure (or implication of same) in that description is unfortunate. If you read a little closer, what's happening is the same type of thing we were discussing concerning end exit tuning. Changing the shape or size of the opening will have an effect on the tune point. The "pressure" they are actually referring to is the pressure waves that cause the reflections both good and bad that utimately end up as the tuning pressure(s) we are trying to capitalize upon. Think about how a Hemholtz resonater works and what factors can alter it's characteristics ... you'll get it.

>>Tell them boys to hurry up before the only H-D I can buy is an electric one. I don't fell like rewinding armatures for more power just yet... <<

Man , I hear ya on that. It's a race to see which happens first ... no fuel to run 'em or the greenies getting them banned outright :>( I hear superconductor technology is supposed to boost low end grunt, but the cryogenic generator required is a big problem!

[Twolanerider]

the Helmholtz resonance

Man, blast from the past.  Haven't heard that term since a physics prof walked in to class one day, made that noise you get when blow across the top of a soda bottle and announced "you all have just learned how to produce the Helmholtz resonance."  Pretty sure I zoned out for the rest of the class though. 

[fuzznut5197]

The use of the term backpressure (or implication of same) in that description is unfortunate.

Well yeah, especially after I cite the source....   Wikipedia!!! 

If you read a little closer, what's happening is the same type of thing we were discussing concerning end exit tuning. Changing the shape or size of the opening will have an effect on the tune point. The "pressure" they are actually referring to is the pressure waves that cause the reflections both good and bad that utimately end up as the tuning pressure(s) we are trying to capitalize upon. Think about how a Hemholtz resonater works and what factors can alter it's characteristics ... you'll get it.

I think I'm getting it! Backpressure implies something static, like a baseline pressure that exists in the pipe at all times. The above never states that, I mean, you can have higher transient pressures that alter the wave tuning but who cares as long as the next pulse is happy. 

I hear superconductor technology is supposed to boost low end grunt, but the cryogenic generator required is a big problem!

No problem! Ln2, not cold enough, but with all those He atoms being made in those fusion reactors, liquid helium will be cheaper than the dollar menu at McDonalds!   

[Jeffd]

No problem! Ln2, not cold enough, but with all those He atoms being made in those fusion reactors, liquid helium will be cheaper than the dollar menu at McDonalds!   

[/quote]

There's a dollar menu at McDonalds? mmmm.

[ederdelyi]

Backpressure is "static" and not good ... methinks the fella just upchucked one of them "pages" :>)

[fuzznut5197]

Ok, I gots a book with a million unsteady gas flow formulas, and not one mention of "backpressure".
I'll read that one! 

[easyman]

Just saw a post on exhaust and wanted to know which 2-2's work as well as a 2-1 just to have more choices. I just always thought the 2-1's were the hot lick.

Any of the V&H pipes that have the power chamber perform well, I had the big shot longs for dressers and loved them. The blue line is the V&H the red is the D&D fatcat 2 into one.

[attachment removed after 60 days by system]

[Reddog74usa]

LOL!!!!!!! And all I wanted were some opinions on what would be a good set of 2-2's for a FXR with a 113.

[ejk_dyna]

<<LOL!!!!!!! And all I wanted were some opinions on what would be a good set of 2-2's for a FXR with a 113.>>

Cycle Shack 2" tapered, stepped headers, 2-2

PHD232T  Talk to Ron or Chaz at axtell or Bobby Woods.  These are the best for high output, big inch.  You need to modify/remove the baffles...can you say LOUD.

[Don D]

Would agree with that, plus
Basanni Pro Street

[BrianK]

Um, scuse me guys, but by "2 into 2" don't you really mean two one-into-ones?  That's what I see most Harleys running.  Not sure I've ever seen a 2 into 2 for a Harley.  Could be wrong....

[iclick]

If you're talking bottom end and mid-range performance, NONE!!!

Actually, the Dyno-Tuned Jackpot mufflers from Fuel Moto emulate a 2-into-1 and provide performance that's equal or very close using stock head pipes.  The trick is their asymmetrical design with a 3/4" reversion cone in the left muffler, which reduces exhaust flow through that side.  The beauty of this setup is the cost compared to 2-into-1's.

[Admiral Akbar]

Well these are 2 into 2 as far as I can figger..




Set of these will cost you about $140 and some welding time.. They flow real well and give a flat curve.  Max

[txtech]

Well these are 2 into 2 as far as I can figger..




Set of these will cost you about $140 and some welding time.. They flow real well and give a flat curve.  Max

where did you hide the crossover max???

[Admiral Akbar]

where did you hide the crossover max???

No crossover?? Do you mean a way to connect both exhaust flows together? what do you need a crossover for?? Max

[txtech]

where did you hide the crossover max???

No crossover?? Do you mean a way to connect both exhaust flows together? what do you need a crossover for?? Max

so you dont overexhaust it.

[L-]

Hahahahahaha...... now I do think that is funny!  So, final verdict on 2 into 2's performing like a 2 into 1 goes to???

L-

[Admiral Akbar]

so you dont overexhaust it. Hysterical

\
Nope cross over makes it worse... Kept finding the airfilter gone from under the cover and sticking out the end of the exhaust pipe...

Hahahahahaha...... now I do think that is funny!  So, final verdict on 2 into 2's performing like a 2 into 1 goes to???

L-

That's easy.. The one, either 2 into 2 or 2 into 1, that works best for the motor wins..

Max

[txtech]

so you dont overexhaust it. Hysterical

\
Nope cross over makes it worse... Kept finding the airfilter gone from under the cover and sticking out the end of the exhaust pipe...

   your throttlebody was too big and you blamed it on the exhaust.


Max

[Admiral Akbar]

your throttlebody was too big and you blamed it on the exhaust.

Well I guess if I went smaller on the TB, it wouldn't eat my air filter..    It's probably choke on it..  Max

[FLTRI]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ.. Running a 95 Kromewerks ARIIIs do well. Bigger motors seem to like the Kromewerks AR100s but I've founf that they like a little tweaking to get the most out of them..

Max

Probably more to do with your cams then the pipes, don't you think?

[Admiral Akbar]

Heck most 2 into 1 seem to loose low end but pick up on peak TQ.. Running a 95 Kromewerks ARIIIs do well. Bigger motors seem to like the Kromewerks AR100s but I've founf that they like a little tweaking to get the most out of them..

Max

Probably more to do with your cams then the pipes, don't you think?

Ok Where's the gloves??  Max