I just got a 58mm ported intake manifold for my 95 z28. Before I put it in this weekend I plan on getting a ported throttle body aswell. I can obviously put in put in a ported throttle body up to 58mm that will work with the intake manifold, but I was wondering if I should even consider a 52 or 54mm one instead?

 

If you dont have any additional mods just use the stock throttle body.
If you have ported heads, cam and headers then you should also consider a bigger TB.

 

thanks for the feedback. good to know

 

Also be aware a bigger TB without retuning a A4 car for it will do transmission damage over time.

I would not bother swapping the intake.

 

Sorry for the stupidity but a4?

 

4-speed automatic transmission = A4. In 93, a 4L60, 94-02 a 4L60E

 

Also be aware aftermarket TB's are commonly designed to dump idle air into the main plenum instead of the Idle Air Plenum passages GM designed in our intakes. This screws up your idle. I would be prepared to tune if you want it acting like stock again.

 

well im not sure if makes a difference but mine is a 6 speed....not automatic

 

The A4 is shifted by the PCM, based on throttle position, etc. If you alter the throttle body, you alter air flow vs. throttle position, and that throws the shifting off, requiring a reprogram. This is not an issue with the M6 (6-speed manual).

Might want to add a "signature" with basic info about your car - year, model, engine, trans and any major mods. That makes it easier for people to help you.