streetzlegend

iTrader: (8)

Has anyone tested or seen any discussion regarding the 3.0 stock headers?

I have wondered if my stock headers would be a choke or restriction. Whats the most power we have seen via stock 3.0 headers? Didnt HLH and Mardigra run stock headers back in the day with forward ypipe?

emdot

iTrader: (4)

i wish i could find my old dyno graphs for you. Are you talking NA power, or like a supercharger setup? Also, what motor are we talking about.

As far as my old setup went, 3.5, supercharged at 11psi, AEM methanol injection 50/50 mix, stock 3.0 liter headers, Warspeed y-pipe out to 3 inch straight pipe. that made 374whp/339wtq at 6400 rpm. Dynojet, SAE corrected.

i dont know if thats what youre considering high, if it isn't, completely disregard my post lol

t6378tp

iTrader: (69)

Dont remember anything on here but on my350z a few guys in the 400-450 made decent gain going from oem to aftermarket shorties. Also a few rmt guys on ls1tech had the same results going from oem to headers but they reported slower spool times but by only a few hundred rpms. They did later say that the problem was corrected by heat wrapping them. The front mount ls1 guys are making anywhere from 600-800hp on stock truck and zo6 manifolds but these like the hr manifolds and are closer to equal lenght headers and not manifolds

Not sure how much time or money your looking to spend by there is also the option to port the stockers

Kevlo911

iTrader: (36)

Headers is the way to go son

streetzlegend

iTrader: (8)

well I don't want to change the stock headers but was worried that they might stop me from making power.

emdot, high hp meaning 500ish.

emdot

iTrader: (4)

Yeah I figured after I Typed all that you were talking 500+ lol. I'd go some sort of equal length, the oem are short and look super restrictive. I've been out of the loop, what beast you got up your sleeves this time?

streetzlegend

iTrader: (8)

3.5, hx40 20psi.

I think I am going to stick stock for now, hal had stock n he was making good power.

Nealoc187

iTrader: (23)

yes hlh and mardigras were on stock headers. hlh made 500whp with spray. i honestly can't remember mardi's max numbers. i made like 420whp without spray.

i don't believe that the headers are a restriction, personally. a lot more restriction going on on the intake side of things at least in my case.

t6378tp

iTrader: (69)

you'll hit 500hp on OEM manifolds but pretty if you were to switch to something equal length without any others changes you'll see an increase in power

t6378tp

iTrader: (69)

What's your hp goal I think that's what will determine whether it's worth the trouble

streetzlegend

iTrader: (8)

My goal is to his 10.9 ET lol. so w/e it takes to get there. Now that I got the intake part taken care of, and now that the headers arent going to limit me (by nealoc's confirmation of hlh, margi and his car), I will start pushing this thing harder!.

I really prefer not to touch the headers t6378tp, dont feel like dealing with it lol.

t6378tp

iTrader: (69)

Headers are a b!tch, I didn't swap mine till I pulled the motor

aic96max

iTrader: (12)

turn up the boost homie. max out what you got first (:

streetzlegend

iTrader: (8)

Will do, thats the plan. I want to check for boost leaks before I start bringing up the boost though. I want this existing setup to be as efficient as possible.

ajcool2

iTrader: (43)

Yup I'm never doing it with the engine in.

TurboA32

iTrader: (36)

There's no limit on the power you can make on stock headers but I don't think you will gain much or if any power from stock to aftermarket headers but i do know I use the stock headers for the quality. Aftermsrket ss headers usually crack sooner or later which is what happened to someone I know but quality is key

SmoothMax

iTrader: (2)

Absolutely right! Contrary to what a lot of people think, bigger isn't always better.

I posted in a different thread about going bigger downstream from the turbo to reduce backpressure, but it's different upstream. You don't necessarily wanna go smaller cause your turbo will run out of steam at toward the top end, but you don't wanna go bigger either. The reason being that unlike an N/A setup that relys on matching exhaust velocity to backpressure for the purpose of scavenging, a turbo setup relys mainly on the exhaust velocity in the collectors, upstream of the turbo, in order to start making boost. So going bigger reduces that velocity and can have the opposite effect you're looking for.

All in all, you should be fine with the oem manifold.

t6378tp

iTrader: (69)

Nobody said anything about going bigger just a better design

bamboomerang

iTrader: (14)

FWIW, there is a section on this exact topic in Alexander Bell's 'Forced Induction Performance Tuning A Practical Guide to Supercharging and Turbocharging' - not specific to a VQ (covers the RB though IIRC) - the general consensus was the heat retention of cast iron usually outweighs the potential design advantages of SS tubes. Worked/extrude honed stockies is generally considered the best bet in terms of high HP efficiency.....probably not in cost/effort though. ... bassically the returns of cranking up the boost on SS tubes will diminish faster than on iron.

streetzlegend

iTrader: (8)

Thanks for the feed back guys. I will consider this case closed. Stock headers it is (good because I didnt wanna get in there to change them lol). Already checked for some boost leaks, tighten some clamps, then gotta hook up the nitrous, and party starts.

t6378tp

iTrader: (69)

Must be great living somewhere the tracks never close

emdot

iTrader: (4)

seriously! we have this stupid thing called winter where it gets cold and occasionally snows. NE FTL.

streetzlegend

iTrader: (8)

"Winter?" That word does not ring a bell, what is it?