Great info STiLL.STiLLWILL said:hope this helps,
is this true? does an unequal length header make more topend power than an equal length header? i always thought that equal length was better all over the powerband.STiLLWILL said:That STi belongs to Hummer. He's running the Gruppe-S unequal length header with the Jet Hot 2000 black thermal coating. You will 'feel' great gains with an aftermarket header if you just have the basic mods(intake, turbo back), but the gains from an aftermarket header are more substantial with an upgraded turbo and engine management. Basically what I'm saying is you will see more gains with an aftermarket header if you have gone with more significant upgrades.
Another thing to consider is what kind of power you're looking for. Generally, unequal length headers have great top end power gains, however, this design yields an inherent turbulance at the collector causing the 'lumpy' sounding idle. On the other hand, equal length headers are generally(pipe design will vary depending on manufacturer) great for low-mid gains. This design also smooths out the exhaust flow at the collecter heading into to the up-pipe which will also result in a smoother but buzzier sounding exhaust.
The Gruppe-S header($400) has been proven to gain as much as 13hp on regular WRX's. It's a well-crafted piece:
Another header is this one made by GP MOTO ($800)which is closely based on the Blitz header made for the STi in Japan. This is an equal length pipe design. Note that this header has an integrated up pipe, making purchasing an aftermarket up pipe unnecessary. This has been known to gain as much as 33hp on a regular WRX, but it's also DOUBLE the price of the Gruppe-S piece. It's a well-constructed piece as well:
hope this helps,
My wife has said that the mod frenzy must stop until the Xmas presents are bought. The UTEC is the next big thing, but it looks like several months before it is released.blueballs said:Hummer, you are the mod king on this forum!
That's quite a list...