meilers

I just watched an interesting TV program over the weekend where a mechanic added a new set of headers and a fuel system to an older-model V8 N/A engine and saw a whopping 100 HP increase. Yet I never see anyone here mention headers as a must-do engine upgrade... Does the boxer configuration not benefit from increased header flow volume? Or are the stock headers good enough that no one has a better alternative?

Daredevil

iTrader: (5)

from what i've seen (and i am most likely wrong) headers dont' do much for wrx's

the gt spec 2 headers claim 25 HP and 35 TQ, but i wanna know on who's dyno...

oldmansan

iTrader: (4)

GPMoto header/uppipe, and my car is running good on the stock turbo. I'm running with or better than STIs at the track. I've seen some negative posts about the GTSpec. I also wrapped my header/uppipe and part of the downpipe.

San

Kevin M

iTrader: (12)

The flaw with aftermarket headers is heat loss- the stockers aren't so great, but they have heat shields and insulation, so they lose very little heat. That means that almost all of the exhaust energy leaving the cylinders is reaching the turbo. When you put aftermarket headers on, they do 2 things bad- they usually have larger runners, which reduces the pressure of the gas as it reaches the turbine wheel, and they lose lots of heat, which further reduces the pressure and energy transfer at the turbine. Wrapping/coating them goes a long way towards remedying this problem, but at a price- Stainless steel tends to crack or warp when it is forced to hold a lot of heat for long periods of time. These are the reasons why I'm using stock headers on my RS-T swap with an STi shortblock and VF30.

oldmansan

iTrader: (4)

larger diameter tubing is detrimental. My tubing is small. Although the WRX is fairly new, I've seen no threads concerning stainless pipes cracking or warping. Please point me to any pertinent threads.

San

porkchop

if you ever looked at the GT spec headers, they use slip joints, which prevents cracking and warping. The heat lost going from stock headers with shields to stainless steel headers are minimal, but what it does reduce is turbulance which allows for better flow.

we have seen many cars with GT spec headers making 15 to 20 more tq on the dyno. Power is definitly felt in the mid and higher range. Like all the other performance parts, the power it makes depends on what it's used in conjunction with.

Tommy
www.mpjperformance.com