what is the stock size throttle body for a 96 z28 48mm or 52mm.

 

The throttle body bores are 48mm. The holes in the intake manifold are 52mm.

 

so would a 52 mm throttle body on a stock car help?

 

i wouldnt imagine so. not a noticeable difference anyways, it would help if you were using forced air intake or had a pretty sick intake. just my thoughts

 

a larger throttlebody may actually hurt power due to the lower velocity of the incoming air.

 

No, not really, but if you do a heads/cam upgrade, then it is a different story.

 

I dont think so. I first went to a ported TB and could feel a small difference, nothing amazing, just better repsonse. Then went to a 58mm tb and could definitely tell a difference. Idle was healthier, throttle response was great, I would recommend using a larger throttle body.
I read a lot of opinions before i bought mine, it seems that people are pretty much split on the idea. Just try it, if you dont think it helped. you wont have a problem selling it most likely to make your money back.

 

I installed a ported 52mm TB on my 93 Z28. I had a hooker catback, cai, ory, and a reprogrammed chip. I got 5rwhp and 3ft lbs of torque on the dyno from one on a basically stock car.

 

The money would be better spent on something other then messing with the throttlebody. Unless you have an upgraded top end and valvetrain that flows more air a stock LT1 won't benefit much from a bigger throttle body

Oh and there is a difference between "feeling faster" and being faster. Feeling faster means spending money on a part or parts that doesn't add much real power but the brain tricks you into thinking it is faster.

 

48mm is stock size on all LT1 throttle bodies.

 

Very little difference in power on a stock car. You may feel a difference in throttle response as a larger TB will increase flow more with the same change in the angle of the throttle plates.

Rich

 

No. The plenum effectively decouples the throttle body from the intake process. It's just a "valve" that can be opened and closed. It not like a carb, where velocity is important to the fuel mix.

 

It wont benefit much from a bigger throttle body, but it will benefit from it in my opinion. My car feels a lot healthier with it on there. Get one for a good price and decide for yourself like i said.
And yeah theres a difference between feeling faster and being faster. With a bigger throttle body, i wont say ive proven it myself, but i believe it will be faster and feels faster for sure. Guess its just a mod that doesnt have true numbers gained ironed out yet.

 

There is a gain in the range of 3-5 rwhp on the chassis dyno.

Rich

 

Was that on a stock car? Slightly modded? Any idea??