# DOES SIZE MATTER intake and throttle body



## TxSoldier6.0 (Nov 4, 2008)

Ok so im looking to buy an intake and throttle body for my 05 does "mm" size matter and will i have to change anything or just bolt them on and go 
thanks


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## svede1212 (Nov 1, 2005)

any significant change should have a retune. your air fuel ratio is going to change


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## GM4life (Mar 18, 2007)

Most systems out there are 90mm and the newest one is 92mm from FAST. Stock is 90mm so thats not much of a differance, the intake will allow alittle better flow. I think there is a 100mm floating around for the serious drag racer types.


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## Rukee (Feb 8, 2007)

You need to have enough motor for the larger size. I believe if you just stick a 100mm throttle body on a stock motor, bottom end throttle response will suffer.


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## lukekeith (Oct 27, 2006)

I just had the FAST 92 put on my car today... here is my performance mod history in order and gains so you can understand how/why the FAST 92 helped...

stock 05 GTO = 330rwhp
LT headers + pully = 370rwhp
catback exhaust = 372rwhp (waste of money)
cam .610 = 402 rwhp
FAST 92 = 432 rwhp

Had all my install & tune done here in town at LG Motorsports, awesome crew by the way.

So in my opinion, the 92mm makes a huge difference!!! Granted, some of that added power came from opening up the cam a bit, but it's still significant. And if you are wondering why I'm not more like 450rwhp, it's because I have nitrous and the timing can't be as extreme or the engine will explode first time I engage =).... 

FAST 92 was well worth the money!


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## svede1212 (Nov 1, 2005)

something to keep in mind is a part like a TB isn't going to give xx HP necessarily. the engine is an air pump. if the TB isn't the choke point in the air's path changing it won't make any difference. if you make it breathe more thru parts that you add somewhere else then it MAY be the bottleneck that when opened up gives better performance. i think in the last example there was something else going on because at that HP level a TB won't give that big of an increase, as much as a cam.


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## GTOsarge (Oct 9, 2007)

You won't really realize any performance gains until your able to get the air out of the other end. I had the Fast 92 installed along with the cam and headers. I noticed a big change because of doing it all at once. I plan on better heads down the road but with the A4 I'm pushing the limits and any more will require the tranny to be beefed up. So in short unless you have the cam, headers and free flow exhaust the TB or intake would be a waste. Keep us posted on your decision. Good luck!


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