Not if they are properly constructed headers.....so yes.....because all the headers currently on the market other than the full race stuff are junk.
Yeah from what i have heard the wrap does a great job of insulation, but they hold moisture in. Moisture + High Temperatures = corrosion.
The stock header unit with the stock heatsheilds are perfectly fine. The stock units make over 600 wheel hp.
You don't really belive that the stock header is a good design do you? Just because you can make power with it doesn't mean its good.
It absolutely does...it works there is no denying it. That doesn't mean that it is not a horrible design. Un equal length is not ok....especially not on a turbo car. Its amazing that it works as well as it does. Matt
I've not seen any other aftermarket header make more power than the stock unit....all else being equal. Please do prove me wrong, I would like to find something that is lighter, and outperforms the stock one in ALL AREAS. So far the *ONLY* area that the stock one rates low is weight. It is kinda heavy...but it sure does excel in all other areas. The engineers certainly did an awesome job with this piece over the previous one.
Full-race makes good stuff. Great results on EVO's from the stuff I installed a long time ago. Interesting that the power drops off at 6400 for the FR manifold... I'd like to see a C16 fuel'd 35R car that makes 550~600 with the stock headers swap to the FR pieces and see what kind of gains can be had. *must search nasioc for possible results* Still....35hp and 20tq is a good gain in the other RPM ranges. Dunno if its really worth the nearly $2g's....unless you've got the $ and are building a pure race car.
http://forums.nasioc.com/forums/showthread.php?t=1235702 Interesting read. I also found a few threads on ported stock manifolds. The ported one on my car sure is a hell of a lot faster than the stock one that was on it.:naughty:
Even if its ported its still a bad design. They way subarus sound isn't a good thing, despite what people think. That sound is exhaust gasses hitting the turbo in an odd sequence...it should be nice and even. They made all the power in that graph with out retuning. There is way to much exhaust back pressure, too much egr in the cylinders, with all that crap going on they won't run the timing that they should. Bad engineering on SUBARUS part, all they had to do was throw the twinscroll lower on there and it would have been better. Matt
http://forums.nasioc.com/forums/showthread.php?t=974977&page=3 Another good read...showed the Perrin equal length making a substantial gain over stock. This was also independent testing.
Does anyone know if the '08 STi has an equal length header? I thought I saw a spy video on here a few weeks ago and I could have sworn it sounded equal length.