New dyno numbers, 415 WHP

[IsaacHayes]

On a roots style blower that sucks in air through a TB and pressurizes after it, a larger TB is a must however. Same for N/A.

[HayesPerformance]

I assume that As appose to a "Custom" intake that the 96+ intake would also suite as a good intake upgrade over the 91-95 intake in a turbo setup.

So from what is being said, Would it harm any if I already had a 70mm TB and put a turbo?


Matt, Where did you get, or put your oil feed???

I want to know all the details cause I'm building a engine for a turbo setup.

[BlueFlame]

I would assume that, like exhaust, too much cross section has a detrimental affect on performance. Air, like liquid, increases speed when you shove it through a smaller opening (think thumb over the garden hose). By using a larger throttle body, you would slow the air down, thus lowering your torque numbers, and, with a turbo, increasing spool up time, correct? Don't get me wrong, yes you can shove more air through a larger opening, but at some point it makes no difference. Just what I've read, as I have no physical experience, but Matt's setup makes sense to me.

[Joseph Upson]

I would assume that, like exhaust, too much cross section has a detrimental affect on performance. Air, like liquid, increases speed when you shove it through a smaller opening (think thumb over the garden hose). By using a larger throttle body, you would slow the air down, thus lowering your torque numbers, and, with a turbo, increasing spool up time, correct? Don't get me wrong, yes you can shove more air through a larger opening, but at some point it makes no difference. Just what I've read, as I have no physical experience, but Matt's setup makes sense to me.

You are correct, to much or to little flow area can have an adverse effect. Formulas with appropriate numbers entered would help diffuse the debate. A particular runner or throttle body apature does not become a restriction until you attempt to move more air through it than it can flow without resistance. For example no two of us can blow enough air through a 52mm hole to benefit from moving up to a 60mm hole, so bigger can in some cases be more overkill than benefit.

[Guest]

Ben I don't know much about Matt's setup but Chris West also used a stock fiero TB on his older engine which was a 3.4tdoc (turbo)...and before he sold his setup it was about a 400hp engine @ about 12-13psi.

HAHAHA no freaking way was his setup making 400 hp on a bone stock buick grand national T3 turbo on 12-13 psi. Turbo won't support that airflow at that boost level.

Not only that but I have personally talked to people that drove the car when it was at Wheatstock a few years ago. It was taken out onto the street and a mildly modified if not stock Grand prix GTP 3800 supercharged car whooped up on Chris West's car. Now that is definately NOT 400 hp.

If tb size doesnt' matter too much then put a 30mm tb on all the boosted setups here because it obviously doesnt' matter.

Yes going too big can be bad and hurt response. But come on a dohc had a larger tb then that stock. How can putting on a smaller tb from a factory motor make more power? Putting an 88 mm tb on a 3.4 dohc might not make more power and cause more lag, but not a 60 or a 62 or hell even a 64 or wahtever a stock size tb is.

I dynoed a stock 52mm vs a ported DM 57 mm on a pushrod 3.4 with a turbo. I spooled quicker, and made more torque. I didnt' make any more peak power, but its my guess the stock intake, and the heads were now becoming a larger restriction. But according to you guys here that is impossible. Just think what it would do when its bolted to a dohc motor that is already sucking more air then a 2 valve pushrod turd.

And Ben I recommended Matt going to a 57 mm ported unit because then nothing has to be refabricated on his intake manifold. The DM version is just a ported out version of the stocker so its easy to swap.

A smaller tb is going to hurt transient response from vacuum to boost because the motor has to work that much harder to suck in the air through a 52mm tb then say a 57 or even a 62. See what I am saying here people? THe longer and harder it is for the motor to suck air through a smaller tb, the longer its going to take for the motor to spool the turbo because their won't be any exhaust gasses to do so.

I guarantee it will make more power, and spool quicker, and make more tq. I guarantee it!!! If you have time Matt I recommend it. Hell I have a DM ported tb I will give it to you if you want to dyno test it.

[ForcedFirebird]

CFM is CFM, no matter which way you look at it. In a NA engine, though, velocity is just as important as flow. There is guy I know that built a nice motor, but over ported and has no power until the boost kicks in, really lame on the bottom end. I will be experimenting with TB's and boost once my motor is up and running. Testing will be done with a stock 3.1 TB, a stock 3500 TB, and a 75mm TB. I plan on making passes with all three configurations both NA and boosted, just because of curiousity that I have.

[IsaacHayes]

3500 TB is electric BTW. I look forward to your testing!!!
On a boosted turbo app, a larger TB I don't think would matter going WOT under boost, as the air expands when it enters the plenum anyways...

[ForcedFirebird]

3500 TB is electric BTW.

Thanks, I was unaware of that. Either way, I have the 3.1 and N* TB's to test with, and will get one off any car I can to get to work. It will be easier for me to swap between "standard" GM TB's with throttle cable and TPS's. (Not concerned as much with IAC since I will be using MegaSquirt1 that doesn't support stepper motors).

[nocutt]

That is cool as long as the data is interpreted scientifically...pk power is not always everything...the whole usable band should be analyzed...

[IsaacHayes]

Right, who cares about 8peak hp increase at redline when you could have 5 over the whole band.

Running in the 1/4 though should tell which is more beneficial, as long as the conditions are the same. Hopefully FF can do it in one day, and have all the stuff needed to swap the TB's right there for each pass.

[ForcedFirebird]

That's kind of the plan. With MS, I can tune both on the street, then bolt on each one at the track and change the tune instantly before the next pass. Either way I'm still a couple of months away to be N/A, and a couple more for boost (I'm guessing). And you know as much as I like to blab, you guys surely will know the results

[Guest]

Happy Birthday matt