If I am running an LS/VTEC and planning to make roughly 185-200whp, do I need to upgrade my stock 240cc injectors, or stock LS fuel pump for that matter? The only fuel flow modifier I have is a fuel pressure regulator which can only go so far, or would it suffice alone?

 

GSR's and ITR's come with 240cc injectors, so I think they should be sufficient for an LS/VTEC, at least until you start to heavily modify it. As for the pump, I'm not sure if there are any flow differences between the VTEC and non-VTEC cars, but I don't think you need to worry about that if you're going to remain close to stock. If you look at (JDM)ITRs that make about 170 whp stock on 240cc injectors and the stock pump, you probably don't need to upgrade the fuel system that much if you're aiming for slightly higher whp, unless the LS pump differs from ITR one, which I don't think it does. Further on down the line, you may want to up your injector size to maybe 310cc and get a high-volume intank pump, but they probably aren' necessary right now. You should be able to work with your FPR to get enough fuel for 185whp.

 

Well I heard from sources that my injecotrs will be maxing out just after a few boltons around 7500 and up... So i'm in the market for injectors and may go with 350cc, but now the question will be if the stock LS fuel pump can run with that...but then again, i wouldn't have to run as high a fuel pressure with the higher flowing injectors, so maybe the pump can hang...damn, it's not like i can dyno these things b4 I have them in to get everything running well... so frustrating at times I say.

 

Easy way to test to see if your fuel pump can hack it is to get a remote fuel pressure guage, if the pressure drops under hard acceleration, the pump can't keep up. If it stays at the fuel pressure you're looking for, you're fine, simple.

 

That seems simple. Now what about the injectors? I know guys running 12s with stock injectors and others saying that just having an ITR intake manifold and headers maxes out their injectors around 7500 to 8500 depending on mods?

 

Injectors will just limit your power output if they aren't big enough, which is easiest to notice on a dyno or with a standalone fuel system.