Did you read the by-line on that paper? Enthalpy and Mattback.

They used a the nastiest of nasty, weld-els, 90's and T's, log manifold. In fact, that info is probably on TR. The paper also has absolutely zero to do with what we're talking about or external wastegates. Allow me to digress....

Hey, no one mentioned pushrods and long tubes. You don't get to chime in on technical stuff! So here's the deal with that test. With a huge turbo at 13psi and a free-flowing motor with medium cams, that log is easily the biggest restriction. What you're seeing is the removal of a restriction that is far and away limiting the power. The low boost level really shows this off. On my brother's 2871 car, it only made 30whp more at 19psi with HKS cams over stock, but made 50+whp more if you compared them at 15psi. This car makes 350whp at 1 bar on stock manifolds.

So yeah, 2871 makes 350-360 at 1 bar. At 2psi more on the tubular/3082 would have made 375-380whp (10whp per 1psi is generally accepted on 2.0L). My 3071TS made 370-380whp at 1 bar on 2 different setups. Notice a trend here? It's not coincidence. It's math. Barring restrictions, if you fill the same 2.0L with 13psi worth of air and 93 octane it'll make the same power regardless of what's supplying that boost. Without flow restrictions like small exhaust housings or compressor going inefficient, the main variables are down to compression ratio and VE. That 2871 doesn't make the power that the 3082 and 3071 did in my example because of the slight VE difference from the stock manifold and the tubular (among other smaller things). The log/3082 didn't make nearly the power the tubular/3082 did because the log absolutely kills the VE of the engine.

So maybe it is like headers after all.

 

I dont doubt the tubular made more power, my sarcasm was on the completely mismatched setup, like you said, they took the shittiest manifold they could create, and compared it to their $1200 ? piece. When I see a back to back for a stock manifold, maybe ported ? vs their manifold, on a similar engine, but with a 2871, or 3076R, and it make a 20+ hp difference, i'll recognize it as an upgrade, but still wouldnt run one. I'm pretty certain that 3076R with the housing for the tial wastegate, which doesnt require the cut down wheel like the 3071R T25 flange version, on a stock S15 manifold, would more than keep me happy for a daily driver setup. Hell a 2871R 52T with that exhaust housing and greddy install kit would do it too

Ah hell, theres technical discussion going on around here. Someone needs to hurry up and change stuff back to shitty suspension arms, and how the less offset you have, the cooler your wheels are, no matter the width.

 

everytime we argue about tubular manifolds vs stock im going to point to this. haha

 

When you step up over a 60mm compressor wheel, you might have a leg to stand on.

Oh and did you completely miss the part where they compared a shitty hackjob log manifold, NOT a stock manifold ?

Your point is now invalid.

 

DICK! Hahahahaha

 

See ya went all ADD on me, and didnt fully read everything, and now your comparing log manifolds, to $1200 tubulars, and somehow bringing stockers to the comparison when they werent included.

 

It's worse than that. The manifold in question was an off the shelf unit that you can currently buy at Enjuku as a kit. 100's of people run this. The FR manifold back then was closer to 1400, I think. This was in 2002-2003ish. Not many parts were around back then.

Oh yeah, by the way Vapor, a former Admin, had a 2540 (2876 in Garrett numbers) back 5-6 years ago on his SR. It made 400whp. That was before the big migration to the 2871r started.