Pontiac G8 Forum banner

102mm intake to 90mm throttle body adapter?

6.8K views 4 replies 3 participants last post by  Lukes_g8  
#1 ·
Hey guys thinking about getting a TSP 102mm intake manifold (anyone have any thoughts on this manifold?) but want to keep the stock throttle body so I can keep my same intake. It comes with an upgraded 102mm throttle body but figured a 102mm manifold to 90mm TB adapter would be more common. If anyone knows of a 102 to 90 TB to intake adapter that would be helpful as well. Thanks in advance
 
#2 ·
You don't need any adapter. Same bolt pattern and seal between the TB and manifold.
 
#4 ·
Is a 90mm TB a restriction? Only if the heads and cam and exhaust ALL outflow the TB . Your tuner will be able to tell you by the peak MAF signals. If the engine doesn't outflow the intake and MAF system then the TB is not a problem.
From Accufab site a 90mm – 1369cfm. From F.A.S.T. on a 427 cu with ported heads made 11 more HP over the 90mm TB