I currently have a stock wrx and I am waiting for my Perrin Turbo back exhaust and my TurboXS UTEC computer to come in the mail. In about a monthe or so I am probably going to be installing a header, although I am unsure about which header will be best to install in my WRX 02.

I was thinking about either the Cusco Header or the GT Spec Header. These two "apear" to be at the top, but I am not sure. The reason I can't just decide is because the GT Spec is $499 and the Cusco Header is $1149. If they are about the same HP gains I will just get the cheaper one.

Please help, and any advice will be greatly appreciated.

 

I wouldn't even recommend getting one. Just get a down-pipe and up-pipe instead with what you are going to pay for an exhaust manifold. It isn't only they are really expensive (most of them), they aren't really that great on a stock turbo and even many aftermarket turbos.

 

why arnt they good with the stock and some aftermarket turbos

 

This has been talked about before, but it basically has to do with the physics of exhaust flow and temperature. I think I get a little long winded when I try to explain it. It would be better to just get an up-pipe and down-pipe with that money instead of a header. Or, get the up-pipe and engine managment.

 

Thanks I appreciate the help. I hope that some time in the future I can help you two out as well.

 

What you get will vary wuite a bit between the designs. For instance, people with the GT Spec headers have reported lower boost threshold (more lag) but more power in the top end.

I have the MRT headers, which have pretty small primaries (smaller than stock, actually) and is a 4-2-1 design like the GPMoto and I saw very little change in peak HP, but about 15-20 ft/lbs of torque in the low end accompanied by significantly improved drivability. Above peak horsepower, torque/power drop off a little faster than wih the stock setup. This directly compared to the stock manifold + Vishnu up-pipe. Quite a different result than the GT Spec owners are reporting.

Different designs will yield very different results, and there's very little REAL data available. As was said many vendors compare a stock WRX vs one with headers & uppipe. Of course you'll make big gains everywhere if you remove the cork before the turbo.

Primary size is probably the largest influence on your turque curve. For the most part headers will SHIFT your powerband up or down, and really only broaden it slightly.

 

I'm not saying that a header will do absolutely nothing. I'm just saying for what it costs for one with what it will do for you isn't worth it. I guess you could call it a cost : power gain ratio. I have an aftermarket exhaust manifold on my car with the stock turbo and I didn't get much out of it. Sounds cool, though. I got it, though, because eventually I'm getting a different turbo. The stock manifold is good for the stock turbo. As I said before, going into the physics of it is long winded.

 

I just installed the gt spec header/uppipe. It is awsome my car now pulls to redline instead of falling on its face ~6k rpm only paid like 500 for header/uppipe. uppie alone is like 200 or more for a high quality one. the header/uppipe fit perfectly. i would recomend it to anyone.

 

Yes, but very soon I will be replacing the stock turbo with a IHI-34. This is the reason I am looking for an upgraded exhaust manifold.

Thanks for all of the responses people. Really helps.