headers, 3" exhaust, p&p heads

[JohnnyC]

so I finally took the dive... I have a pair of p&p heads, more than 50% better flow than stock, headers, and a 3" full exhaust with carsound cat and summit turbo single in/out muffler going on the car, replacing my stock log manifolds and S-pipe dump after a 2 1/4" high-flow cat. I'm seeing mid 14s on average with my stg. 3 clutch, flywheel, cold air intake and solid driveshaft with a best run of 14.3 in 68* weather nice and dry and dead hooking my tires. Should I go to 24# injectors and tune? I'm also considering some rockers as well. My eventual plan is a stroked cammed monster, but for the short run, i figure I can use the heads/rockers on my next project.

my question is, can anyone give me a guesstimate on what kind of improvement I can see? I'm too excited to wait :)

figuring if I pick up injectors cheap and rockers used, could be an easy add, and hptuners to tune it all right.

[kristen]

Re: headers, 3" exhaust, p&p heads

i would steer you away from the rockers. only because with what you have done your not really going to see a difference. maybe 6-8 hp. and for the price that they are, it's insane. but now if you where to build the whole engine or even cam it you "could " do the rockers. when i cammed my camaro i ended up p&p my heads, cammed it, stock everything went back in with a 3 angle valve job. i upped my fuel injectors and put an adjustable fuel pressure reg in there too at the same time.

you will need a tune if you up the fuel injectors. the car won't really get that far depending on big the injectors are.

as of right now you might want to think about a tune just to get the best hp for your buck.

[JohnnyC]

Re: headers, 3" exhaust, p&p heads

I will get on that. Possibly a stupid question, I do consider myself technologically able and somewhat knowledgeable about my car and very much so about computers overall, but how hard is HPtuners to figure out?

[kristen]

Re: headers, 3" exhaust, p&p heads

to tell you the truth. i hate computers. so i got it. and had other people use it on my car. never really got indepth with it. i ended up selling it cause i had a guy who could use his hp tuner on my car ne ways. my car has a pretty comp. set up so i only trust dyno jets to tune my camaro now.

all in all i was too ignorant to try to learn it.

[Bird_Of_Prey]

Re: headers, 3" exhaust, p&p heads

You want to do heads, with no cam? My bet is that you will kill performance and actually go slower. A pair of hogged out heads will do you no good without the right amount of lift. Most ported heads lose velocity anyway. You would see a much bigger gain with a cam for MUCH less money. I put down 218rwhp untuned on a DynoJet with cam/lid/headers.