Factory ported throttle body vs 80mm bbk

[cv8 munro]

I have got my standard throttle body ported and polished and have justbeen given a 80mm BBK throttle body which would give the best results

[lowhsv]

80mm bbk its bigger

[VXXXSS]

out of curiosity, what size is the inlet into the actual intake manifold itself compared to the diameter of the throttle body??

and therefore what effect does a larger bore throttle body have when used with a stock intake manifold with standard restriction???

chris

[white lie]

Not sure how big the original manifold size is, but you can open them up with a little bit of work. If you take the throttle body off, you can take the o-ring out and open them up to that size and use a gasket to seal it instead. I'm sure there's more info/photos on how to do it on here somewhere.

[klink]

74mm i believe but it tappers down slightly again inside the manifold


working the standard manifold does make a difference on a before and after dyno run.