Hi guys here is my set up 383 Motor forged everything with 9:1 comp w/ Stock Heads, a CC305 cam, Canton Oil Pan, P1SC Procharger w/ 2 Core Inter cooler, 12psi pulley Borla Catback, Air Foil, Street Tuned MSD 50# Injectors, AFPR, Jet-Hot Lts & "Custom" built Mufflex Y-pipe, Rebuilt Trans w/ 2800 Pro Torque converter...


The car put down about 427RWHP 5800 rpm and about 500 foot pounds of torque at about 3600 rpm but the previous trans/yank torque converter gave out and we had to stop the dyno run

so my question goes out to the sc guys what throttle body should i be running (yes i know the heads are stock will upgrade when i have the money)

 

biggest you can go on a stock unported intake is 54mm. AS&M makes them

 

A lot of people run the stock TB and are making a ton of power. I don't see a good reason to drop ~$300 on one. If you are saving for heads - then put that TB money towards the heads.

-Scott.

 

i can always grind out the manifold if i wanted to use a bigger throttle body... my question is more towards how restrictive is the stock 48mm on a supercharged engine

 

yes that's my goal is a really good set up on the heads i am shooting for an honest 500-550 rwhp and able to drive the thing everyday if i want to...

 

I'm running a 58mm. I haven't had the car on the dyno yet though. I know you are using a 12psi pulley, but what psi are you seeing? The P1SC is basically the same as an S-trim and I wasn't seeing more than 4psi with maxed out pulleys. My heads are stock, but ported, so the TB may be the difference. The more you open the motor up (TB, Heads) the less boost you will see, than you will need a bigger head unit, and on, and on, and.........

 

I would do a set of heads first, than intake and TB. Put your money where the power is made.

 

its your air filter... pull it off and see how much your making i had this same problem with my P1SC was running a 4 inch pulley only seeing 4-6psi. pulled it off and i was at close to 12

 

And something to remember is that just because you are seeing less boost on your gauge doesn't mean your motor is making less power.

The amount of psi you are seeing is the amount of air that is 'leftover' and can't get into the motor. So in other words if you were seeing 8 lbs of boost on a stock motor and then put heads and a cam and now are only seeing 4 lbs that means you are letting a lot more air into the cyc chamber which will make that much more power.

In other words don't just focus on how much 'Boost' you are seeing...there is a lot more to it than that.

If you have the money for the TB now, its not going to hurt. One less thing to buy later down the road...

 

The only way to test this would be to compare manifold pressure to the pressure directly in front of the throttle body. If the pressure in front of the throttle body is higher than the manifold pressure while in boost, then the TB is a restriction. Has anyone ever done this?

 

a quick log with datamaster will tell you if you have a restriction there too

 

i see just about 10 pounds of boost at about 5800 rpm (this is with stock heads and a cc305 cam )

 

Stock tb is just fine for your goal, I doubt you would see any gain at all with a 58mm....