HarleyTechTalk

      Are you saying the 2-1-2 will out perform (Horsepower wise) a good 2 into 1 pipe? I new the 2-1-2 performed well but better then a 2-1 on the top end?

Quote from: gabbyduffy on August 12, 2015, 08:01:37 PM
      Are you saying the 2-1-2 will out perform (Horsepower wise) a good 2 into 1 pipe? I new the 2-1-2 performed well but better then a 2-1 on the top end?

Me thinks not...

Judges ruling please? .........Bzzzzzzzzzzt, nada...

Quote from: gabbyduffy on August 12, 2015, 08:01:37 PM
      Are you saying the 2-1-2 will out perform (Horsepower wise) a good 2 into 1 pipe? I new the 2-1-2 performed well but better then a 2-1 on the top end?

Off the shelf pipe
Maybe not outperform in all cases.  but equal 

Quote from: 1FSTRK on August 12, 2015, 04:56:57 PM

Quote from: q1svt on August 11, 2015, 10:48:20 AM
The old style head pipe are dated.

Most 2-1 are design for mid-to-top end

True duals for stock to mild builds are good option

2-1-2 are good for stock, mild and performance builds

Great post
The old school thinking went out the window when the 2-1-2 and x pipes came out.
The key is the additional muffler volume of these new systems.

👍🏼 Good info right there!
Bob

Quote from: strokerjlk on August 13, 2015, 08:30:43 AM

Quote from: gabbyduffy on August 12, 2015, 08:01:37 PM
      Are you saying the 2-1-2 will out perform (Horsepower wise) a good 2 into 1 pipe? I new the 2-1-2 performed well but better then a 2-1 on the top end?

Off the shelf pipe
Maybe not outperform in all cases.  but equal

Need to look at the specific pipe in question:

Most 2-1 tend to have stepped pipe sizing and or a larger collector (that is generally good for mid-top end performance, simply by design)

The V&H/Kury 2-1-2, Fuel Moto (w/larger cross under), etc, do not have the steps and have a smaller diameter collector. Helps the bottom end and middle, but the dual mufflers help the smaller collector, at lower RPM's the pipe works like a 2-1 that had a small collector, as RPM increases the added flow increases out the left muffler (like a 2-1 with a larger collector).

Think of a Y collector verses an X    (the narrow section of an X is only about 1-1/4" long)

So it really depends on the specific pipe and over all build...

these are two dealer built stage 4 103's
one has a boss zilla 2-1 and one has power duals with crusher mufflers.

Quote from: Nowhereman on August 11, 2015, 11:49:50 PM
Every time I have had the bug to swap out pipes, I always keep going back to a 2 into 1 for the best performance.
Low end to high end, nothing works better for the street or almost all racing applications.

Nothing??? What about these here true duals?

[attach=0]


Then again, these are the "original" true duals: Cycle Shack dual shorties. With that nice big wide torque curve and no saggy dip in the low end, no way I've put a 2:1 set up on it. And the sound, oh the sound....   

-JW

Quote from: JW113 on August 13, 2015, 07:41:13 PM

Quote from: Nowhereman on August 11, 2015, 11:49:50 PM
Every time I have had the bug to swap out pipes, I always keep going back to a 2 into 1 for the best performance.
Low end to high end, nothing works better for the street or almost all racing applications.

Nothing??? What about these here true duals?

[attach=0]


Then again, these are the "original" true duals: Cycle Shack dual shorties. With that nice big wide torque curve and no saggy dip in the low end, no way I've put a 2:1 set up on it. And the sound, oh the sound....   

-JW

pull the baffles and it will swap hp for tq. probably bust 130 hp

Quote from: strokerjlk on August 13, 2015, 06:33:38 PM

these are two dealer built stage 4 103's
one has a boss zilla 2-1 and one has power duals with crusher mufflers.

Jim, wow never would of thought they would be that close... I'm thinking the D&D extra length used on the bagger pipes helped the bottom end, and a little surprised the HP for the PD didn't fall off a little on top.  Well they are both made by great companies, hats off the their R&D teams.

Quote from: q1svt on August 13, 2015, 08:00:13 PM

Quote from: strokerjlk on August 13, 2015, 06:33:38 PM

these are two dealer built stage 4 103's
one has a boss zilla 2-1 and one has power duals with crusher mufflers.

Jim, wow never would of thought they would be that close... I'm thinking the D&D extra length used on the bagger pipes helped the bottom end, and a little surprised the HP for the PD didn't fall off a little on top.  Well they are both made by great companies, hats off the their R&D teams.

blew my mind too.
IMO both pipes are letting the cam dictate the curve

Which exhaust on the graph makes +5hp and +12tq @ 1250rpm?
Bob

Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

If your going to base things on information that has nothing to do with Harley engines why not just bolt on a nice two stroke expansion chamber.
You may want to research the power curve of the F1 engine in the 2-6000 rpm range and then re think your conclusion.

Quote from: FLTRI on August 11, 2015, 10:23:53 AM

Quote from: KaritheFinn on August 11, 2015, 10:19:48 AM
Ladies and gentlemen,

my question today is if everything else is to be kept the same but only exhaust is changed from

OEM headers with slip-ons to true dual headers with same slip-ons
or
OEM headers with same slip-ons to 2-1 exhaust such as Supermeg
or
true dual headers with same slip-ons to 2-1 exhaust such as Supermeg

How does torque and hp change with each change, increase or decrease? Will true duals and/or 2-1 bring or lose numbers compared to OEM headers?

I'm after info of which exhaust would give me the most torque in my FLHR.

Freeflowing (open) slipon mufflers with the stock headpipe (w/cat) will preserve bottom end torque and power increase all running areas. That's the most economic way to get to where you want to be.
Don't forget to get it tuned for best running (cooler) as well.
Bob
Bob

FLTRI..... just to be clear. The stock 2009 (catless) head pipe will out perform the newer stock head pipe with the catalytic converter still inside rite? (with equal free flowing mufflers of course)?
                            Your comment about "stock head pipe (w/cat)" is throwing me off a little.

Quote from: 1FSTRK on August 14, 2015, 01:38:30 AM

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

If your going to base things on information that has nothing to do with Harley engines why not just bolt on a nice two stroke expansion chamber.
You may want to research the power curve of the F1 engine in the 2-6000 rpm range and then re think your conclusion.

FWIW, a 2-1 and a 2-1-2 BOTH have a '1'.... the '1' is a collector

What happens after the 1 has less overall effect than the design, length and pipe sizing of the [ '2', '3', '4' '5', '6' ] & '1'

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

The dyno doesn't lie! Just ask Bob, he tuned it.

I guess I'm not all that concerned about what race engine tuners do, since I don't have one of those. Don't those motors spend most of their (short) life in the upper rpms? This bike is more of an urban assult lane splitter. For the look, the sound, the wide power band, dual shorties seem to work just fine for my application.

-JW

Quote from: 1FSTRK on August 14, 2015, 01:38:30 AM

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

If your going to base things on information that has nothing to do with Harley engines why not just bolt on a nice two stroke expansion chamber.
You may want to research the power curve of the F1 engine in the 2-6000 rpm range and then re think your conclusion.

Todays F1 engine formula is for V6 1.8 liter engines that are turbo charged so that is a different ball game.
In the past, though, V8s were the formula and they were naturally aspirated.
Their exhausts were things of beauty, Inconnel steel wonders that were developed after millions of spent dollars.
Power bands were from 8000 to 16000 rpm.
Almost no flywheel to speak of, using multi disk small diameter clutches.
Those engines were all using 4 into 1 per bank.
They made torque in gobs and high end HP.
I never seen any pipe design that went from 4 to 1 to 4, or 4 into 1 into 2.
Headman did for many years have a 4 into 2 into one that won quite a few pro stock records back in the 70s though.
I've read lots of books on free energy extraction in the world of exhaust.
Smoky Yunick's book should be required reading.
I respect all who post here, don't get me wrong.
Some things being said though go against the law of physics.
All well designed exhaust pipes for four cycle engines have collectors just slightly larger than the primary tubes.
At no time have I ever read that it would be advantageous to do something like a 2 into 1 into 2 as the spent energy / exhaust is so cold that getting it out of the system is best.

Theory is great, but there are so many variables that effect the quality of power and how different exhaust designs effect it that to focus in on one type of exhaust as the "best" is really not very valid. The rest of the engine design greatly determines what effect different pipes are going to have. One example is cam design. Generally the mild, short duration, little or no overlap cam designs aren't going to show much difference in exhaust design as far as "OEM headers vs true duals vs 2-1". I doubt that F1 engines EVER used this type of cam as it would REALLY limit an engine's ability to even reach 8k-16k RPM. Engines designed to run at 8k-16k RPM require a lot of duration in cam timing with a lot of overlap...and maximizing the effect of scavenging in the exhaust will be very rewarding. In addition, styling is important to a lot of people including the sound, neither of which is much of a consideration in F1 racing, so never much of a reason for them to test exhausts with that in mind...therefore I'm not surprised that you've not seen 4>1>n except where n=1...no reason for them to even consider it. I've never seen any data on 2>1<8 either...why would there be? The cool thing about StrokerJ's graph is that it's VERY useful to someone who is making a decision about his essentially stock Harley that's designed to live in the 2k to 5k RPM range. It says that there is essentially no difference in performance so don't let that determine the choice. The OP can make his decision based upon other criteria like sound or looks. However, if you're building an engine to perform in the 8k-16k RPM range, then yes...his graph is useless info.

Quote from: Nowhereman on August 14, 2015, 09:34:27 AM
I never seen any pipe design that went from 4 to 1 to 4, or 4 into 1 into 2.

Need to look at some of the current American factory performance V8's

4-1\
        into an x pipe back out in to two exhaust...
4-1/

here is one that at the x pipe splits out to 4...

http://www.americanmuscle.com/boss-quad-exhaust-2015gt.html

edited: here is a exhaust by Smokey for T/A racing he did for Ford Racing 302 Boss, 2-1, 2-1, with an H pipe between them... the other half that I cannot find pulls the right/left banks together and back then out each side. 

Don't forget the 2-1-2  X pipe Carl wegner designed for Cup cars  . Still using that same technology 40 years later .
Willie G commissioned him to design a pipe for the 120 motors .
Like he told me . No reason to change what works . So thus the X pipe .

I run Wegner's 2-1. When I asked Carl if it would make more power than the X pipe ? He smiled and shook his head No.

Quote from: Bigbluff on August 14, 2015, 11:35:25 AM
Theory is great, but there are so many variables that effect the quality of power and how different exhaust designs effect it that to focus in on one type of exhaust as the "best" is really not very valid. The rest of the engine design greatly determines what effect different pipes are going to have. One example is cam design. Generally the mild, short duration, little or no overlap cam designs aren't going to show much difference in exhaust design as far as "OEM headers vs true duals vs 2-1". I doubt that F1 engines EVER used this type of cam as it would REALLY limit an engine's ability to even reach 8k-16k RPM. Engines designed to run at 8k-16k RPM require a lot of duration in cam timing with a lot of overlap...and maximizing the effect of scavenging in the exhaust will be very rewarding. In addition, styling is important to a lot of people including the sound, neither of which is much of a consideration in F1 racing, so never much of a reason for them to test exhausts with that in mind...therefore I'm not surprised that you've not seen 4>1>n except where n=1...no reason for them to even consider it. I've never seen any data on 2>1<8 either...why would there be? The cool thing about StrokerJ's graph is that it's VERY useful to someone who is making a decision about his essentially stock Harley that's designed to live in the 2k to 5k RPM range. It says that there is essentially no difference in performance so don't let that determine the choice. The OP can make his decision based upon other criteria like sound or looks. However, if you're building an engine to perform in the 8k-16k RPM range, then yes...his graph is useless info.

I agree with your statement.
My motor makes it money just about the same way with all useable power coming in at 2500 and being done realistically by 5500 to 6000.
Still, the tune of it makes it real sensitive to pipe design.
So it sounds like cam design is the crucial variable here as long as you can supply fuel to it.
A radical cam design is more sensitive to exhaust pipe design than a mild bump stick.

Quote from: Nowhereman on August 14, 2015, 09:34:27 AM

Quote from: 1FSTRK on August 14, 2015, 01:38:30 AM

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

If your going to base things on information that has nothing to do with Harley engines why not just bolt on a nice two stroke expansion chamber.
You may want to research the power curve of the F1 engine in the 2-6000 rpm range and then re think your conclusion.

Todays F1 engine formula is for V6 1.8 liter engines that are turbo charged so that is a different ball game.
In the past, though, V8s were the formula and they were naturally aspirated.
Their exhausts were things of beauty, Inconnel steel wonders that were developed after millions of spent dollars.
Power bands were from 8000 to 16000 rpm.
Almost no flywheel to speak of, using multi disk small diameter clutches.
Those engines were all using 4 into 1 per bank.
They made torque in gobs and high end HP.
I never seen any pipe design that went from 4 to 1 to 4, or 4 into 1 into 2.
Headman did for many years have a 4 into 2 into one that won quite a few pro stock records back in the 70s though.
I've read lots of books on free energy extraction in the world of exhaust.
Smoky Yunick's book should be required reading.
I respect all who post here, don't get me wrong.
Some things being said though go against the law of physics.
All well designed exhaust pipes for four cycle engines have collectors just slightly larger than the primary tubes.
At no time have I ever read that it would be advantageous to do something like a 2 into 1 into 2 as the spent energy / exhaust is so cold that getting it out of the system is best.

Consider this, the reason for the 2:1:2 is for the value of a proper 2:1 design but there's the problem of these big V Twins need big volume exhaust systems meaning they really work better with less restriction than 1 muffler.
Once the tuned portion (2:1) of the exhaust is done (after collector) the engine doesn't care where the exit volume comes from.
This also means should be able to make same power with less db.
Bob

Quote from: FLTRI on August 14, 2015, 11:04:18 PM

Quote from: Nowhereman on August 14, 2015, 09:34:27 AM

Quote from: 1FSTRK on August 14, 2015, 01:38:30 AM

Quote from: Nowhereman on August 13, 2015, 11:51:14 PM
Impressive plots but, don't mean squat to me.
Not sayin your not telling the truth and all but, When the best engine designers on earth who have all the money they need to produce a race engine use 2 into 1s or  4 into 1s ala F1, then that tells me something else.

If your going to base things on information that has nothing to do with Harley engines why not just bolt on a nice two stroke expansion chamber.
You may want to research the power curve of the F1 engine in the 2-6000 rpm range and then re think your conclusion.

Todays F1 engine formula is for V6 1.8 liter engines that are turbo charged so that is a different ball game.
In the past, though, V8s were the formula and they were naturally aspirated.
Their exhausts were things of beauty, Inconnel steel wonders that were developed after millions of spent dollars.
Power bands were from 8000 to 16000 rpm.
Almost no flywheel to speak of, using multi disk small diameter clutches.
Those engines were all using 4 into 1 per bank.
They made torque in gobs and high end HP.
I never seen any pipe design that went from 4 to 1 to 4, or 4 into 1 into 2.
Headman did for many years have a 4 into 2 into one that won quite a few pro stock records back in the 70s though.
I've read lots of books on free energy extraction in the world of exhaust.
Smoky Yunick's book should be required reading.
I respect all who post here, don't get me wrong.
Some things being said though go against the law of physics.
All well designed exhaust pipes for four cycle engines have collectors just slightly larger than the primary tubes.
At no time have I ever read that it would be advantageous to do something like a 2 into 1 into 2 as the spent energy / exhaust is so cold that getting it out of the system is best.

Consider this, the reason for the 2:1:2 is for the value of a proper 2:1 design but there's the problem of these big V Twins need big volume exhaust systems meaning they really work better with less restriction than 1 muffler.
Once the tuned portion (2:1) of the exhaust is done (after collector) the engine doesn't care where the exit volume comes from.
This also means should be able to make same power with less db.
Bob

Potentially yes.
If sound is the factor your trying to manage.
If not, then the spent gasses, (energy) is depleted by going into atmosphere better by less restriction and that would out to the lowest pressure point... open atmosphere.
So, if we are in agreement on that, then the 2 into 1 into 2 cannnot be superior to a 2 into 1 for power generation purely based on exit restriction of spend gasses.
To some, maybe esthectics, certainly not weight.

Sorry, can't decipher your English:
"If not, then the spent gasses, (energy) is depleted by going into atmosphere better by less restriction and that would out to the lowest pressure point... open atmosphere."

Then:
"... then the 2 into 1 into 2 cannnot be superior to a 2 into 1 for power generation purely based on exit restriction of spend gasses."

Are claiming the 2:1:2 has less exit restriction so it will not outperform a 2:1 with more exit restriction?

Bob

The only person who posted comparative data is StrokerJLK.

Comparing an F1 engine to a valve motion limited Harley is silly.