Funkybird

My setup consists of a forged 355 that made 423rwhp @7psi with a p1sc and twin intercoolers. Now im gettin an f1a and already have a front mount to go along with it.
My question is, is how bad is my stock throttle body hurting me at this point?

CALL911

Going from something like the P1SC, to an F1 is like going from a V6 Camaro to a Camaro SS, and then asking how much the paper air filter is going to hurt you compared to putting in a K&N.

My point is, there's a bit more you might want to consider than just the stock TB, but if that really is the only thing you want to know, I think it might restrict your boost maybe even 15%, and will cause some definate power loss over going with a 58mm.

Funkybird

Ok, what else should I consider? I know its going to be a HUGE difference between blowers. The reason i'm asking about the throttle body is cuz i'm getting a 52mm for free and was thinkin about selling it and gettin a 58mm or a monoblade. So I guess the question I should have asked is would it be worth the extra money to go bigger than a 52 or just keep it?
And for the record my heads are ported LT4's and the intake is a port matched LT4 as well. I can go into more detail if it helps.

CALL911

Concerning your TB, personally I would go with a 58mm, especially going with an F1 unit. Anything restrictive like that between the blower and the intake has got to make a difference, but that will be up to you on if the extra money for a 58mm will be worth the power gained from it.

The motor is the big thing you need to be concerned with. Heads, intake, all that stuff is nice for performance, but the thing you need to concern yourself about first is the motor. A P1SC can run on a stock bottom end just fine, but once you move to a D1SC, or especially to a F1, your motor needs to be able to survive the power that the bigger blower is going to put through it. Not sure what all is forged in your 355 but, you need to have a lower CR, a good set of forged pistons, forged internals, ect. ect. Not to mention all the supporting mods like dual fuel pumps, bigger injectors, ignition, intercooler, methanol injection, a good dyno tune. Without the motor being built for the level of power the F1 will take you to, or having the correct supporting mods done, your motor will be toast in no time. This doesn't even include the other things you need to think about as well, like having a tranny/clutch that will take the power, driveshaft, rear, ect. And then on top of that, if you want to actually use any of that big power, you need to consider suspension work, otherwise your gonna be spinning everywhere and losing races to guys with 200 less RWHP that can hook up.

Funkybird

Thanks for the help man! I had ls1 speed build me this motor with them knowing my future plans that I am now actually going through with so it's all forged with a CR of 8.75:1. The fuel system needs some work, currently I have the racetronix/walbro 255 with the hotwire kit and 42# injectors. As for the ignition I have 6AL and blaster coil. I'm running EPP's front mount and custom piping with procharger's big red bypass. Meth and dyno tune will come shortly. Stock trans with Mcleod street twin, stock rear till spring time comes. I have full BMR suspension other than torque arm but i'm gettin that in the near future as well. Should be fun
What size injectors are you running at your power level?
Here's a link to a thread I made recently. Let me know what you think!
https://www.camaroz28.com/forums/sho...d.php?t=549364

CALL911

Sounds like you are almost ready in my eyes. Get a second boost referenced 255lph in tank pump, some bigger injectors, a good methanol injection system, and for sure a new rear along with a good tune and you should be good to go.

I am running Mototron 60# injectors. They are perfect for the 15#'s of boost my D1SC is pumping out, but would probably be to weak for the fuel that the F1 would require.

Funkybird

I guess i'll have to start checking the fueling section and study up on what I need.
I appreciate the help!