HOW BIG OF TB DO YOU NEED FOR YOUR MOTOR? INFO HERE.......

[uglyDougly]

  Welcome Hoist, I'm not your official greeter but I'd like to take a look at your big-throttle example and try to shed some light. Since this thread is about throttle sizing.

 Hoist said; 'it was designed for a 58mm HPI TB' and then; 'going to a 62mm HPI TB with their hi flo A/C. Not much difference on peak numbers, but it cleaned up the whole bottom, and raised TQ substantially'

 I don't accept that increased velocity across the TB has any beneficial effect on cylinder fill, (and there are many who will disagree) but the opposite, decreasing velocity, most certainly, isn't true.

 The only reason for an increase in torque at low RPM is tuning. One of your dyno results had to have been incompletely/improperly calibrated. I'm not attacking your tuner either, it's just that the torque characteristics of your build is the result of everything after the TB/manifold and the only thing the TB.
/manifold can do is take away power. TB restriction starts at the power peak (maximum, total air flow) and increasing restriction will take away farther down the RPM band. (Such as closing the throttle.)

  If you look at 20%, 40%, 60%, 80%, & 100% throttle dyno charts (after the AFRs are finalized) you will see that the torque is exactly the same at the lowest RPM, and each increasing throttle position will extend the same torque curve out to a higher RPM. If opening the throttle doesn't increase the low RPM torque, how can installing a larger throttle increase the low RPM torque?
 I've attached a dyno chart as an example.

 Doug

[attachment removed after 60 days by system]

[Admiral Akbar]

Good stuff Doug.

I'm not sure if you can get the injector timing from the fuel system but did the spray time also appear the same? Max

[Hoist!]

 Welcome Hoist, I'm not your official greeter but I'd like to take a look at your big-throttle example and try to shed some light. Since this thread is about throttle sizing.

 Hoist said; 'it was designed for a 58mm HPI TB' and then; 'going to a 62mm HPI TB with their hi flo A/C. Not much difference on peak numbers, but it cleaned up the whole bottom, and raised TQ substantially'

 I don't accept that increased velocity across the TB has any beneficial effect on cylinder fill, (and there are many who will disagree) but the opposite, decreasing velocity, most certainly, isn't true.

 The only reason for an increase in torque at low RPM is tuning. One of your dyno results had to have been incompletely/improperly calibrated. I'm not attacking your tuner either, it's just that the torque characteristics of your build is the result of everything after the TB/manifold and the only thing the TB.
/manifold can do is take away power. TB restriction starts at the power peak (maximum, total air flow) and increasing restriction will take away farther down the RPM band. (Such as closing the throttle.)

  If you look at 20%, 40%, 60%, 80%, & 100% throttle dyno charts (after the AFRs are finalized) you will see that the torque is exactly the same at the lowest RPM, and each increasing throttle position will extend the same torque curve out to a higher RPM. If opening the throttle doesn't increase the low RPM torque, how can installing a larger throttle increase the low RPM torque?
 I've attached a dyno chart as an example.

 Doug

Thanks for the welcomes gang! Interesting reply and certainly some valid points, and not unexpected at all. It's the typical response when I mention this approach to performance mods on CVO 110's. However, that consistent dip in that dyno chart is EXACTLY what we removed with the larger TB on my bike. No other way til we tried it. My engine was designed by a fairly reknowned builder that worked with HD FI engineers to help develop performance modifications specific to HD's oddball 110 CVO engine. Thru their testing, then our own afterwards, we determined that the CVO 110 needed to get them crappy EPA 255 cams outta there ASAP and get that motor GOBS of flow. The motor's kind of an anomoly, if you would. 2 methods are being used to increase performance. One is the traditional method you guys all speak of here by changing the design, shrinking things, and increasing velocity that way. The other approach utilizes the size and increases velocity by increasing the flow thru the fixed openings. Adding more CFM thru the same size opening also increases velocity, does it not? Well we found that by doing it that way, yields better streetable hi performance than doing it the traditonal way you guys are used to. I've had many discussions about this with engine guys around the country. Some agree, some try to tear that theory apart. All I know is, that by going that route, a very hi peformance motor can be built, while still being very streetable, lower CR, good gas mileage, and lower operating temps. After testing many things, and beating this to death over at CVOHarley.com, many are starting to see this as another valid approach to the 110 engine design. Without going radical, which I certainly didn't want on my touring bike, none over there have acheived my numbers without higher CR's and worse gas mileage. Works for me!

And now I've just started a monster discussion here just tryin to explain it again. But I'd be very interested to see how it's received here as well. Awright lemme have it now!

Hoist!

[uglyDougly]

  I only take offense at the comment about typical response but we need to define the variables then.

  You're saying that there were no engine changes, exhaust changes (including back-pressure), cam changes, cam timing changes, compression ratio changes, inlet or exhaust port changes. The engine was completely re-calibrated for each variable (I would suspect that the top end of the VE tables wouldn't have to be adjusted.)
  Finally, are you talking about differences in low RPM torque at WOT or throttle angles below that?

  Maybe it's time for data?

  Doug

[Hoist!]

  I only take offense at the comment about typical response but we need to define the variables then.

  You're saying that there were no engine changes, exhaust changes (including back-pressure), cam changes, cam timing changes, compression ratio changes, inlet or exhaust port changes. The engine was completely re-calibrated for each variable (I would suspect that the top end of the VE tables wouldn't have to be adjusted.)
  Finally, are you talking about differences in low RPM torque at WOT or throttle angles below that?

  Maybe it's time for data?

  Doug

Hehe!!! Oh no, not all! Everything was modified to get the desired results. Many exhaust tests, much cam and head modelling on the computer by the engine designer, etc. This is by no means a stock HD CVO 110 anymore. I'm not a designer or builder. Just a very passionate owner who wants what he wants, and is willing to be a Guinea Pig if I think it makes sense. A different approach was taken to the traditional modifications with good results. The increase in TQ at low RPM was at both WOT and other TP's as well. We spent hours and hours on the dyno at Joe's Cycle and with Bean at Big Boyz, with both a PC and a SERT. I lost my hard drive last year and all my stuff was gone. But I'll try to scan some the tests done at Joe's which is all I have hard copies of, besides a few final runs from Bean after final SERT tuning. Thanks for your interest on this Doug. Haven't I seen you at CVOHarley too? Same screen name and Avatar for me there. You should be familiar with what I've been playing with over the past 2 years and 2 blown motors!

Hoist!

[uglyDougly]

  I don't have time for two foraa (is that the Latin plural for forum?) so usually I only lurk on others.

  To be clear, are you saying that a whole bunch of stuff was changed to get that low RPM torque increase?
  If that is the case, the throttle change may not have had any part in the torque increase. I would say that the increased throttle size wouldn't hurt or help low RPM torque. That could launch another discussion entirely.
  And yes, everything else is what changes/changed the engines torque characteristics.

  Is that a fair assessment?

  Doug

[geezerglide]

Hey guys,

Since this TB topic is on going I would like to ask a question.

Have an 04 SEEG c/w an SE 103" with some mods, Vortec headwork done by SBC Short Block Charlie), Dave Mackie 590 Cams, Stock TB and injectors, Supertrapp Supermeg 2:1 c/w 25 discs, rest engine stock. Dyno at 103 hp and 116 lb. ft. tq.

I have a Zippers 50 MM TB. As a guess would my performance increase and if so what size injectors should I try?

Doug you may be able to chime in on this as a few year back when I had a Jims 120 you recommended the Kuraykyn 57 MM TM c/e 6.63 injectors and I ended up with 131 hp and 134 tq. Again, Vortec Headwork, that time S&S 625 cams I think and V&H pro Pipe.

thanks to all in advance,

geezerglide

[se]

stock inj will work with your motor just fine .. a read some where that you can also install v-rod inj. i run yelow inj in my 120 and have no issues.

[uglyDougly]

  Yes, the stock injectors will work to just over 115HP. Actually, they will probably go over 120 but the duty cycle is usually above 80% around 115.
  With 0.590" cams the potential is there for over 120HP but that depends on everything else about the build.
  The 50mm TB should help make more HP but if it's a 103HP build, the larger TB won't do squat. (won't hurt either JMO.) If you're over 115HP you should go to larger injectors, which would be, as the previous poster offered, V-rod injectors or the same IWP069 Weber Picos that you used on your 124.

  Doug
 

[uglyDougly]

Hoist;
  Now I get it! You're a contrarian just like myself and a lot of other cranky old farts.

  I really did focus on the 'It's the typical response when I mention this approach to performance mods on CVO 110's.'

  I imagine the typical response is something like; 'it can't make more torque with a larger TB!'

  That's assuming that 'typical' folks think small throttles will create torque.

  I don't agree with that nor do I think that a larger throttle will increase the torque.

  The point I tried, (perhaps clumsily) to make was that the throttle size wasn't the reason for the torque increase, and now that I see what you did, everything else you did to the combination is why it gained low RPM torque. The larger throttle just didn't have any effect on it, good or bad.

  I didn't mean that it can't make more torque with a larger throttle, I meant that it won't make more because of a larger throttle body.

  Doug

 

[Hoist!]

Hoist;
  Now I get it! You're a contrarian just like myself and a lot of other cranky old farts.

  I really did focus on the 'It's the typical response when I mention this approach to performance mods on CVO 110's.'

  I imagine the typical response is something like; 'it can't make more torque with a larger TB!'

  That's assuming that 'typical' folks think small throttles will create torque.

  I don't agree with that nor do I think that a larger throttle will increase the torque.

  The point I tried, (perhaps clumsily) to make was that the throttle size wasn't the reason for the torque increase, and now that I see what you did, everything else you did to the combination is why it gained low RPM torque. The larger throttle just didn't have any effect on it, good or bad.

  I didn't mean that it can't make more torque with a larger throttle, I meant that it won't make more because of a larger throttle body.

  Doug

 

HeHe!!! I knew you'd see it my way Doug!!!

















J/K!!!

Hoist!

[GoFast.....]

Hoist;
  Now I get it! You're a contrarian just like myself and a lot of other cranky old farts.

  I really did focus on the 'It's the typical response when I mention this approach to performance mods on CVO 110's.'

  I imagine the typical response is something like; 'it can't make more torque with a larger TB!'

  That's assuming that 'typical' folks think small throttles will create torque.

  I don't agree with that nor do I think that a larger throttle will increase the torque.

  The point I tried, (perhaps clumsily) to make was that the throttle size wasn't the reason for the torque increase, and now that I see what you did, everything else you did to the combination is why it gained low RPM torque. The larger throttle just didn't have any effect on it, good or bad.

  I didn't mean that it can't make more torque with a larger throttle, I meant that it won't make more because of a larger throttle body.

  Doug

 

HeHe!!! I knew you'd see it my way Doug!!!

















J/K!!!

Hoist!

If the signature at the bottom says Doug, list to the man

[Hoist!]

Hoist;
  Now I get it! You're a contrarian just like myself and a lot of other cranky old farts.

  I really did focus on the 'It's the typical response when I mention this approach to performance mods on CVO 110's.'

  I imagine the typical response is something like; 'it can't make more torque with a larger TB!'

  That's assuming that 'typical' folks think small throttles will create torque.

  I don't agree with that nor do I think that a larger throttle will increase the torque.

  The point I tried, (perhaps clumsily) to make was that the throttle size wasn't the reason for the torque increase, and now that I see what you did, everything else you did to the combination is why it gained low RPM torque. The larger throttle just didn't have any effect on it, good or bad.

  I didn't mean that it can't make more torque with a larger throttle, I meant that it won't make more because of a larger throttle body.

  Doug

 

HeHe!!! I knew you'd see it my way Doug!!!

















J/K!!!

Hoist!

If the signature at the bottom says Doug, list to the man

I listen to EVERYONE and take it all into consideration. And I see he's got his chit together. But ya gotta read the small print too man! It says J/K! Just Kidding!!! Hit the Quote button to read the small print, not find the magnifying glass!!!

Hoist!

[GoFast.....]

Hoist;
  Now I get it! You're a contrarian just like myself and a lot of other cranky old farts.

  I really did focus on the 'It's the typical response when I mention this approach to performance mods on CVO 110's.'

  I imagine the typical response is something like; 'it can't make more torque with a larger TB!'

  That's assuming that 'typical' folks think small throttles will create torque.

  I don't agree with that nor do I think that a larger throttle will increase the torque.

  The point I tried, (perhaps clumsily) to make was that the throttle size wasn't the reason for the torque increase, and now that I see what you did, everything else you did to the combination is why it gained low RPM torque. The larger throttle just didn't have any effect on it, good or bad.

  I didn't mean that it can't make more torque with a larger throttle, I meant that it won't make more because of a larger throttle body.

  Doug

 

HeHe!!! I knew you'd see it my way Doug!!!

















J/K!!!

Hoist!

If the signature at the bottom says Doug, list to the man

I listen to EVERYONE and take it all into consideration. And I see he's got his chit together. But ya gotta read the small print too man! It says J/K! Just Kidding!!! Hit the Quote button to read the small print, not find the magnifying glass!!!

Hoist!

sorry that is small print

[mayor]

gofast, were the flow numbers that you listed in the first post a bare TB attached to the flow bench or were they run through a head?  

[GoFast.....]

Doug, The 107" is finally coming together but got to leave town for a week, I always bolt the TB on to check it right after torquing the heads down to make sure it lines up perfect. One time I put a whole bike together and last thing I put on was the TB and it would not fit because the heads were shaved to much and I to tear it all down after I threw a could of wrenches around the garage. Doug you going to fly to denver and help me dail it in on the Dyno since you know so much about the WT





The 55 HPI Fits perfect. Now take it off a starting putting together the rest of the top end. I like the feeling of knowing what the parts togther did on the flow bench, We will see later if it translates into to power later