FAST 78 vs 90mm

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Aug 22, 2006 | 01:09 PM

redtail2426

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From: Rochester,Ny

FAST 78 vs 90mm

Is the only difference the throttle body opening between the 78 and 90mm.Are the runners and manifold itself the same?

Aug 22, 2006 | 03:17 PM

Pipelayaz

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From: Home: Flint, MI Stationed: Charleston, SC

Just get the 90. Stock is 75MM going up a few MM isn't worth it to me especially for the costs of those manifolds.

Aug 22, 2006 | 04:00 PM

redtail2426

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From: Rochester,Ny

that sounds great,anyway is the only difference between the two manifolds the throttle body opening?,are the runner volumes the same??

I know to get the 90,but i am curious if its gains over the 78 are from the larger TB opening..

Aug 23, 2006 | 11:39 AM

GREATWALLTA

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Same everything except the bigger throttle body inlet hole. Very big difference in size. 78 vs 90 mm.

Aug 23, 2006 | 12:31 PM

redtail2426

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From: Rochester,Ny

Quote:

Same everything except the bigger throttle body inlet hole. Very big difference in size. 78 vs 90 mm.

[QUOT

Thanks a lot for the info,i guess we can say that the stock 75mm tb is just to small for a H/C car over 400 rwhp.

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