LS ITB's
10 Second Club
Joined: Nov 2007
Posts: 458
Likes: 2
From: Birmingham UK
How? Given you have free reign and packaging is free choice.
You can tune your trumpet length to your camshaft, and you are not forced into compromise of somebody elses choice of runner length.
Variable ITB would be the only other way that you could do better...
You can tune your trumpet length to your camshaft, and you are not forced into compromise of somebody elses choice of runner length.
Variable ITB would be the only other way that you could do better...
To clarify my point: I am speaking more to real world space/install restrictions in certain cars in addition to the combination of the engine.
Fitting a non-optimal itb (for the engine/use) due to install constraints isn't going to perform better just because it's an itb.
Given the choice, I would choose an itb setup (and I have-twice).
Gentlemen,
Passionate discussion here...isn't it nice?
My background about ITB goes back in the early 60's when may Dad or his friends were driving me in their Alfa Guilietta Zagato, Alpine Renault and other R8 Gordini...
It was the pinacle of ITB and the OEM one's provided for those engines were nammed Solex, Del'Orto or Webber...4 cylinders engines and two double bodies carburators...the injection area was not yet arrived (except for the Alfa that was imported in USA with a mechanical injection, and a big loss of power).
I can say I was grown with the song of those engines revving above 8000 rpm on those ITB...for those that have never experienced it, let's say the music was magic!!!
I will for sure get an ITB system for my now V8 engine as soon as I will find something making sense to me.
Now, I have a lot of respect for you all mounting, elaborating, imagining, realizing, developing something that seems to not really interest a mass production company...I name the ITB for a Corvette in a daily application...but that might happen someday, and I will jump on it.
I have follow your build up since the beginning, your up and downs, watch your videos, read your commentaries, and I have to say, you are persistent with your development, the final result (for now) is great and I am glad you are happy with it.
Nonetheless, I am absolutely not convinced the fonction of an ITB is to make your power shine between 5600/7000 rpm...at all. That is easily faisable with a composite intake, and you can absolutely have a stable idle with the balanced components.
The smothness you found within your tuning or "tricks" along your way to calm down the "kangaroo" effect, is a normal behavior of a FAST mounted with an electronic management...
I know, the engine noise is not the same at all, and the beauty of the ITB is far superior to the plastic piece.
On a technical side, I still cannot agree with your comments, but one more time I am glad you are enjoying your car.
And yes, you can make an ITB electronic injection idle @ whatever "the lowest possible" revs your rotating MOI will permit...
About the sound, you are the winner (or your engine) all the way, contest doesn't exist in this area, you don't need me to say, enjoy it!!!
The torque curve elasticity is more a function of your valve events, but it's true that an ITB is permissive on some valve events you can't imagine realize with a FAST...
Hi RAMPANT,
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
Passionate discussion here...isn't it nice?
My background about ITB goes back in the early 60's when may Dad or his friends were driving me in their Alfa Guilietta Zagato, Alpine Renault and other R8 Gordini...
It was the pinacle of ITB and the OEM one's provided for those engines were nammed Solex, Del'Orto or Webber...4 cylinders engines and two double bodies carburators...the injection area was not yet arrived (except for the Alfa that was imported in USA with a mechanical injection, and a big loss of power).
I can say I was grown with the song of those engines revving above 8000 rpm on those ITB...for those that have never experienced it, let's say the music was magic!!!
I will for sure get an ITB system for my now V8 engine as soon as I will find something making sense to me.
Now, I have a lot of respect for you all mounting, elaborating, imagining, realizing, developing something that seems to not really interest a mass production company...I name the ITB for a Corvette in a daily application...but that might happen someday, and I will jump on it.
I am speaking with experience, ITB's are far superior in every way except cost...
Mine used to kangaroo and **** about at low RPMs, it is now smoooth!
And makes over 500rwhp from 5600-7000+, before it peaked and died, if you can afford them, then they are the only way to go.
Mine used to kangaroo and **** about at low RPMs, it is now smoooth!
And makes over 500rwhp from 5600-7000+, before it peaked and died, if you can afford them, then they are the only way to go.
Nonetheless, I am absolutely not convinced the fonction of an ITB is to make your power shine between 5600/7000 rpm...at all. That is easily faisable with a composite intake, and you can absolutely have a stable idle with the balanced components.
The smothness you found within your tuning or "tricks" along your way to calm down the "kangaroo" effect, is a normal behavior of a FAST mounted with an electronic management...
I know, the engine noise is not the same at all, and the beauty of the ITB is far superior to the plastic piece.
On a technical side, I still cannot agree with your comments, but one more time I am glad you are enjoying your car.
I agree, although I will add in complexity in both mechanical setup, tuning, and installing it with proper filtration that will not kill the power benefits of the itb setup.
I do agree with Christian that in certain setups it just doesn't make sense, and there are setups where it won't make any more power. If the FAST is not a restriction on the motor, the itb will likely not make much more power if at all. Plus the itb has to be of proper size and design for the combo.
The one thing it will always do is idle better. That may not be a big deal for most, but I hate living with engines that are overly loud and rowdy under normal driving conditions. I only want it loud under WOT personally, and nothing sounds better than an itb singing under WOT imo.
I do agree with Christian that in certain setups it just doesn't make sense, and there are setups where it won't make any more power. If the FAST is not a restriction on the motor, the itb will likely not make much more power if at all. Plus the itb has to be of proper size and design for the combo.
The one thing it will always do is idle better. That may not be a big deal for most, but I hate living with engines that are overly loud and rowdy under normal driving conditions. I only want it loud under WOT personally, and nothing sounds better than an itb singing under WOT imo.
About the sound, you are the winner (or your engine) all the way, contest doesn't exist in this area, you don't need me to say, enjoy it!!!
There are some manifolds that will produce a higher peak #, but not many that will produce as wide a torque curve as an itb intake. It's epic in a big motor and really almost like an electric motor (pulls from idle to 7k rpm). One has to experience it to understand. It is different.
Even though my motor was wounded, the first time I took it to an autocorss. Yes autocrossing 530rwhp/522rtq. BTW these are thee wounded numbers.
I had instant power application and modulation. My old set up was 412 LS2 with 510/490 at a little higher rpm with a FAST 90. That motor would snap out on me all the time. I constantly had to tiptoe around the corner exits. There was always the slightest little delay in the power coming ion and I had to guess if my foot was in the right location for the power I hoped the tires would hold. 90% I had too little and 10% too much. There really is a delay that I could sense, nothing like a turbo car but enough to screw you up.
With the ITB I feed into the throttle on exit and if it gives a little wiggle I just lift a hair and it hooks right up again. If you have not felt it, you will not know what I am talking about. My car is cable actuated, so the fly by wire guys, I bet it feels more like the single TB.
I was bitching about local rules that said an ITB moved me into the full on race car Paxxing, but a blown 346 was ok as a modified class. Once I drove the car with the ITB, I understood the rules.
BTW, with the 532rwhp, I raced in a heavy rain on 4 x 315 R888s, and was only 3-4 sec behind an AWD STI. In the dry I was 6 sec ahead of him, but it showed me the throttle control the ITBs gave me. It was very slick and I hardly spun a tire. Unreal!
If you ever have a chance to drive a cable version, take it, you will be impressed, I promise.
I had instant power application and modulation. My old set up was 412 LS2 with 510/490 at a little higher rpm with a FAST 90. That motor would snap out on me all the time. I constantly had to tiptoe around the corner exits. There was always the slightest little delay in the power coming ion and I had to guess if my foot was in the right location for the power I hoped the tires would hold. 90% I had too little and 10% too much. There really is a delay that I could sense, nothing like a turbo car but enough to screw you up.
With the ITB I feed into the throttle on exit and if it gives a little wiggle I just lift a hair and it hooks right up again. If you have not felt it, you will not know what I am talking about. My car is cable actuated, so the fly by wire guys, I bet it feels more like the single TB.
I was bitching about local rules that said an ITB moved me into the full on race car Paxxing, but a blown 346 was ok as a modified class. Once I drove the car with the ITB, I understood the rules.
BTW, with the 532rwhp, I raced in a heavy rain on 4 x 315 R888s, and was only 3-4 sec behind an AWD STI. In the dry I was 6 sec ahead of him, but it showed me the throttle control the ITBs gave me. It was very slick and I hardly spun a tire. Unreal!
If you ever have a chance to drive a cable version, take it, you will be impressed, I promise.
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
Last edited by miami993c297; Aug 19, 2011 at 02:46 PM. Reason: spelling
10 Second Club
Joined: Nov 2007
Posts: 458
Likes: 2
From: Birmingham UK
The cost of the second hand bodies was less than a new FAST and TB...
Hi RAMPANT,
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
As for the fly by wire being the modern way. Absolutely! Why do we have it? To allow marginal drivers to drive faster cars and not get killed. It only makes a good driver slower than he would have been. Now that said, do you honestly think today's tuners remap the traction control to optimise a 700hp motor in a car that came with 325hp? That said, I have a SRT8 that I use in the winter. The stability control on it allows me to relax more on snowy roads, but if I wanted to go fast in the snow, I would turn it off. I hate the elec TB on it too. The feel is like a dead fish.
I own an F Body that came with a near useless traction control. I turned it off constantly even when stock, since it actually upset the car in a corner if it kicked in. I have driven C5s in autocrosses and was in fact quicker than the owners by several secs, but I have to say I hated the computer nannys when I tried them. I was quicker without.
A little something to think about, how far away is the furthest intake valve from the TB. 30-36" Air takes time to react, all it does is move towards the area with a lower pressure. In the ITB they are 6-10" and they are all exactly the same.
I also would challenge any tuner to say he can tune the exact same motor and large cam to idle the same with a single TB. Mechanically they are very different. The lope or surging is due to the intake valve of one cylinder opening early and reducing vacuum in the whole manifold affecting the other 7 cylinders. With an ITB, you have 8 cylinders acting like 8 individual motors connected by a crank and not sharing vacuum signals.
Can you pick a different cam to make it idle better, absolutely, but what are you giving up and you will be giving up something.
Lastly, as for RobZ, his motor is truly amazing, it also is a whole lot different than mine, with very different expectations. His motor would not suit my requirements. I know a lot more about his set up than most. He is the only other person that has the throttle shafts I designed for the Harrrop. They picked up 12cfm alone. Rob helped me a lot with my set up. That is why I know the differences.
If you get a chance to drive one, you will see what I mean by an ITB with FI. Cable actuated will show the improvement more than a by wire set up, the wire takes away the feel it give you.
One last thing, as for the 8 x XXmm calculation of area. Make sure that you subtract the throttle shaft area, plus you have to think about the boundary layer over the throttle blade. The un ported or modified Harrop flowed very poorly. I saw only 283cfm from it. I spent a couple days on a flow bench testing things on it. We gained a total of 47cfm with our changes. I think the ported FAST or Carb intakes flow just as well or better, but you do give something up. It depends what you are looking for.
This is a very interesting thread, I like hearing the different thoughts.
Last edited by RAMPANT; Aug 20, 2011 at 07:23 AM. Reason: spelling.
Thread Starter
On The Tree
Joined: Mar 2010
Posts: 114
Likes: 0
From: Florida
Gentlemen,
Passionate discussion here...isn't it nice?
My background about ITB goes back in the early 60's when may Dad or his friends were driving me in their Alfa Guilietta Zagato, Alpine Renault and other R8 Gordini...
It was the pinacle of ITB and the OEM one's provided for those engines were nammed Solex, Del'Orto or Webber...4 cylinders engines and two double bodies carburators...the injection area was not yet arrived (except for the Alfa that was imported in USA with a mechanical injection, and a big loss of power).
I can say I was grown with the song of those engines revving above 8000 rpm on those ITB...for those that have never experienced it, let's say the music was magic!!!
I will for sure get an ITB system for my now V8 engine as soon as I will find something making sense to me.
Now, I have a lot of respect for you all mounting, elaborating, imagining, realizing, developing something that seems to not really interest a mass production company...I name the ITB for a Corvette in a daily application...but that might happen someday, and I will jump on it.
I have follow your build up since the beginning, your up and downs, watch your videos, read your commentaries, and I have to say, you are persistent with your development, the final result (for now) is great and I am glad you are happy with it.
Nonetheless, I am absolutely not convinced the fonction of an ITB is to make your power shine between 5600/7000 rpm...at all. That is easily faisable with a composite intake, and you can absolutely have a stable idle with the balanced components.
The smothness you found within your tuning or "tricks" along your way to calm down the "kangaroo" effect, is a normal behavior of a FAST mounted with an electronic management...
I know, the engine noise is not the same at all, and the beauty of the ITB is far superior to the plastic piece.
On a technical side, I still cannot agree with your comments, but one more time I am glad you are enjoying your car.
And yes, you can make an ITB electronic injection idle @ whatever "the lowest possible" revs your rotating MOI will permit...
About the sound, you are the winner (or your engine) all the way, contest doesn't exist in this area, you don't need me to say, enjoy it!!!
The torque curve elasticity is more a function of your valve events, but it's true that an ITB is permissive on some valve events you can't imagine realize with a FAST...
Hi RAMPANT,
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
Passionate discussion here...isn't it nice?
My background about ITB goes back in the early 60's when may Dad or his friends were driving me in their Alfa Guilietta Zagato, Alpine Renault and other R8 Gordini...
It was the pinacle of ITB and the OEM one's provided for those engines were nammed Solex, Del'Orto or Webber...4 cylinders engines and two double bodies carburators...the injection area was not yet arrived (except for the Alfa that was imported in USA with a mechanical injection, and a big loss of power).
I can say I was grown with the song of those engines revving above 8000 rpm on those ITB...for those that have never experienced it, let's say the music was magic!!!
I will for sure get an ITB system for my now V8 engine as soon as I will find something making sense to me.
Now, I have a lot of respect for you all mounting, elaborating, imagining, realizing, developing something that seems to not really interest a mass production company...I name the ITB for a Corvette in a daily application...but that might happen someday, and I will jump on it.
I have follow your build up since the beginning, your up and downs, watch your videos, read your commentaries, and I have to say, you are persistent with your development, the final result (for now) is great and I am glad you are happy with it.
Nonetheless, I am absolutely not convinced the fonction of an ITB is to make your power shine between 5600/7000 rpm...at all. That is easily faisable with a composite intake, and you can absolutely have a stable idle with the balanced components.
The smothness you found within your tuning or "tricks" along your way to calm down the "kangaroo" effect, is a normal behavior of a FAST mounted with an electronic management...
I know, the engine noise is not the same at all, and the beauty of the ITB is far superior to the plastic piece.
On a technical side, I still cannot agree with your comments, but one more time I am glad you are enjoying your car.
And yes, you can make an ITB electronic injection idle @ whatever "the lowest possible" revs your rotating MOI will permit...
About the sound, you are the winner (or your engine) all the way, contest doesn't exist in this area, you don't need me to say, enjoy it!!!
The torque curve elasticity is more a function of your valve events, but it's true that an ITB is permissive on some valve events you can't imagine realize with a FAST...
Hi RAMPANT,
We are here in the case where the technology seems a little bit out of age...all race cars (sorry for Nascar) are DBW (Drive By Wire) or Fly by Wire and it seems you responded to an excess of torque on throttle application with great success setting up your ITB to your needs...it took some work, research, money and time if I recall since the beginning of this story...but you have it and I am glad it is working the way you want.
Nonetheless, with a nice electronic management and a DBW orn FbW, the FAST still remains ahead of it, not in sound, not in the idling area low revving, but driving confort and power distribution is a no problem...that is without mentioning the fact that those power level your engine is producing are again attainable with a composite intake.
You will for sure continue to push the enveloppe, will make it even better...
BTW, congrats on your great race results and achievement.
There is one ITB that I find pretty much finalised on this forum here...it is the one from Robz, and his destrocked LS7 revving to 9000 rpm, having its peak power between 7000/8600rpm, and still beeing a daily driver...
Here the thing is speaking and making sense, the application is in line with the concept.
The day where air filters, air boxes and IAT will fit under the hood of a Corvette, there will be an ITB shipping to my home.
And with all you guys, working with passion on this item, that may happen before I become senile.
Christian
10 Second Club
Joined: Nov 2007
Posts: 458
Likes: 2
From: Birmingham UK
Thread Starter
On The Tree
Joined: Mar 2010
Posts: 114
Likes: 0
From: Florida
TECH Regular
Joined: Sep 2008
Posts: 425
Likes: 1
From: Scottsdale, Arizona
TECH Regular
Joined: Sep 2008
Posts: 425
Likes: 1
From: Scottsdale, Arizona
Not sure if Hilborn still makes them or not. When I raced VW's back in the day I ran Hilborn's rotary throttle bodies. They look like a ball valve opened up no throttle plate in the way just an open hole. Granted back then I was using mechanical injection, but the throttle bodies were really great!
Might see if Hilborn still makes something similar
Might see if Hilborn still makes something similar
On The Tree
Joined: Apr 2005
Posts: 167
Likes: 0
Has anybody real life experience of Inglese LS3 8 stack system? With Ez-Efi or XFI?
http://www.inglese.com/news/ing/2013...ction-systems/
http://www.fuelairspark.com/fas/self...gle-headshtml/
http://www.inglese.com/news/ing/2013...ction-systems/
http://www.fuelairspark.com/fas/self...gle-headshtml/
Teching In
Joined: Oct 2006
Posts: 29
Likes: 0
Interesting piece here on the effects of changing trumpet lengths. Look at the dyno chart comparing 40mm and 330mm trumpets.
http://www.emeraldm3d.com/articles/e...length-intake/
Suprising how much difference a couple of inches can make (Wait a minute, that's something my wife said)
http://www.emeraldm3d.com/articles/e...length-intake/
Suprising how much difference a couple of inches can make (Wait a minute, that's something my wife said)
Teching In
Joined: Apr 2013
Posts: 49
Likes: 1
Hey guys sorry to bring this back from the dead but I'm in the market for ITB's for my LS3 race motor.
Im going ITB's for 2 reasons. hood issues and most important response and potential gains.
I don't know what companies are still around from this thread but my searching lead me to these companies.
1st choices and following
Jenvey
3k$
Slp by Luxury performance
1399$
Borla
6250$
kinsler
$?
inglese
4k$
Harrop
5K$
any others?
Also IM looking for feedback on these who own them or had them etc. experience and dyno results after switching. Thanks
Im going ITB's for 2 reasons. hood issues and most important response and potential gains.
I don't know what companies are still around from this thread but my searching lead me to these companies.
1st choices and following
Jenvey
3k$
Slp by Luxury performance
1399$
Borla
6250$
kinsler
$?
inglese
4k$
Harrop
5K$
any others?
Also IM looking for feedback on these who own them or had them etc. experience and dyno results after switching. Thanks
