redtail2426

iTrader: (10)

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

Pipelayaz

iTrader: (2)

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.

redtail2426

iTrader: (10)

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..

GREATWALLTA

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

redtail2426

iTrader: (10)

[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.