i am investigating putting an over size T.B. on my 1999 cav w/ 2.2L. I have intake and soon will have full exhaut w/ header. have any of you done this with a similar setup? i just want to know if i will lose any low end power with a bigger throttle body. i have auto trans so i wont be reving to high heaven

hey whats goin on man . i have a 01 sunfire with the 2200 . i have intake and full exhaust with header. i used the 2.3 HO throttle body which is 56 mm i think . and i love it .. u don't really feel much of a gain or lose lowend but u can feel it higher up ..i would say maybe 2300 rpms till red line .. its nice... i say go for it .. i would't go bigger then 56 though. my friend has the rsm 62mm and well it made his car slow.. i'm not sure about 58 mm .. but 56 is nice.

I have the RSM 62mm TB on my 2.4 w/intake, manifold, header, cat-back, mounts, etc.

1000-2500 suffers a slight loss, couldn't be more than approx. 2HP/2ft-lb but it's hard to tell
2500-4000 excellent gains, especially after 3000RPM, no loss
4000-6000 "I'm Rick James B**ch!!"

I'd still say go with the 56mm, better all around. Not to mention how EXPENSIVE the RSM TB is...

blade0604 wrote:my friend has the rsm 62mm and well it made his car slow..

LOL not even close! Feels slightly less peppy with nice easy daily driving, but sure as hell doesn't make the car SLOWER, just more pleasant when driving easy. Of course, I have a 2.4, maybe you friend has the 2.2 and they just act differently to it?

It really depends how much bigger you are going and if your stock TB is that much of a restriction on the motor. If you go with something really big like say upgrading from a 56 MM to a 62 MM throttle body...that's a bit much. What happends is velocity plays into effect. Because of the bigger throttle body, you'll need more air to build velocity than you did before. This will end up making your powerband move slightly upwards and you'll notice loss of low end power...so if someone does this and thinks their car is slower, it might be or it might be in certain areas of their powerband.

My previous statement also deals with what other modifications you have also. Modifications work hand and hand alot of times.



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NJHK (The JBO Negro) wrote:...so if someone does this and thinks their car is slower, it might be or it might be in certain areas of their powerband.

Well said. Definitely shifts power higher, so it's not necessarily taking power away, if you wanna look at it that way... just moves it to higher RPM, which is where you would be under heavy accelleration. But no matter how much I love my 62mm, I'd still say go for one of the middle-ground sizes, especially since you say that you don't expect to spend a hell of a lot of time at high RPM.

LD9 Fury! wrote:

NJHK (The JBO Negro) wrote:...so if someone does this and thinks their car is slower, it might be or it might be in certain areas of their powerband.

Well said. Definitely shifts power higher, so it's not necessarily taking power away, if you wanna look at it that way... just moves it to higher RPM, which is where you would be under heavy accelleration. But no matter how much I love my 62mm, I'd still say go for one of the middle-ground sizes, especially since you say that you don't expect to spend a hell of a lot of time at high RPM.

Same here...trust me, my setup sucks for N/A, including my 62 MM lol

It's good high end but it takes a bit too long for my tastes to get some nice pulls. I guess that's what happends when you have s**t too big...62 MM TB, 2 1/2" Exhaust, 5 angle valve job...yeah, you do the math. Great for turbocharged systems, Sucks for N/A.



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i really appreciate your input guys. out of curiosity, does anyone know the approximate size of the stock TB? also, among the mid-range sizes (56-58mm) is there a brand you would recommend?

Chase Hess wrote:i really appreciate your input guys. out of curiosity, does anyone know the approximate size of the stock TB? also, among the mid-range sizes (56-58mm) is there a brand you would recommend?

Not sure how companies do it with the OHV motors and their TBs but I'm guessing they do the same thing like they do with the 2.4s and ECOTECs. What they do is take a stock throttle body, bore it out and fit a new butterfly to fit it properly. So when you say brand, don't think more of they made the product from scratch, they just modified a stock part.

Only places I can think of are Jbody Performance and RSM Racing.



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Just out of curiosity (totally not trying to hijack here) what will the new tb mean for fuel economy? i know with some intakes, you can actually increase it

i am considering the same mod

I'm pretty sure the 2200 engine has a stock 52mm TB. Just a point of reference for you guys.



Blown.

Yea i have a 2200 im still in debate on 62mm RsM or 56mm 2.3. Friend told me to also drop down to the 56mm cus im some loss i might recieve w/ RsM at low end that i prolly wont enjoy. But im still undecided because i kinda want the high-end kick and dont know if 2.3 is bolt-on to 2200 or i have to adjust... so im still in the books and on my research til i get my ans or something i can live wit



-Man its just a Cavi Why would you?

Sam G. wrote:Yea i have a 2200 im still in debate on 62mm RsM or 56mm 2.3. Friend told me to also drop down to the 56mm cus im some loss i might recieve w/ RsM at low end that i prolly wont enjoy. But im still undecided because i kinda want the high-end kick and dont know if 2.3 is bolt-on to 2200 or i have to adjust... so im still in the books and on my research til i get my ans or something i can live wit

If Filip is right, don't go 62 MM...that's way too big N/A. That's even big for an ECOTEC N/A and we have 16 valves...the poor 8 valve OHV would suffer lol

Go 56 MM if anything.



www.kronosperformance.com / 732-742-8837

I drove a friend's Cavy the other day, a '96 with the RSM 59mm, as well as the lower intake. His head is also port matched (not a full port/polish) and fitted with 1.6 rollers, and he has a full exhaust, 2.25". Personally, I think my car has a slightly better bottom end, but his just slaughters mine in the upper RPMs. HUGE difference. It's still streetable, though.


Opfer benotigt. Keine Erfahrung notwendig.

Victims needed. No experience necessary.

A friend went from a 62mm to 57 on a 2.4 and saw better gain. It has been said the 57mm is the best size for a 2.4


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