GP MOTO Equal length header one piece for WRX and STi. with integrated up-pipe. Made from T304 stainless steel. 6 Slip joints are used, two in the middle of #1 and #3 primaries and one on each primary prior to the merge of the up-pipe section. Up-pipe section consists of two pipes merging just prior to the turbo flange promote faster spool up which equals less lag. Welds are polished on all flange locations. Includes boss for O2 sensor and EGT sensor.

Primaries are 37” long @ 35mm diameter.
Secondary are 9.5” long @ 38mm diameter.
Collector pipe is 2.5” long @ 48mm diameter.
Up-pipe total length is 12” long.
33 hp 47ft .lb torque gain. Equal length direct replacement no clearance issues. No slip joints fully welded.

 

I'm gonna have to defer to San. That's one area I've not spent any time researching.

 

I think this is the same header that's in this kit

http://www.xcceleration.com/sti.stagekit.430.htm <---That I don't put much faith in.

 

Call San, this is the one he has.

 

Thanks!

Please don't move this Alex!

 

You may want to hold off though, pending the results of this:
http://forums.nasioc.com/forums/show...5&pagenumber=1

 

I think there is one manufacturer and a few different companies putting their stamp on it. The early versions used slip joints, and I guess a few had leaks. Now they're fully welding it. I know mine doesn't leak, as when you "slipped" the slip joints together, you could hardly force the pieces apart. I'd coat or wrap (or both) the outside, I wouldn't coat the inside as I wouldn't want particles flaking later. Seems like an optimistic hp gain, but my car seems to be a freak of nature on the stock turbo. Bob from Eurosport checked mine out when I picked it up from Hypersport, and said because of the small tubing, it should be much better than the header that powered his 376whp WRX. The inside of the flanges was ground down nicely to make the transitions smooth. Mine was $500 and change and included gaskets. I can't say yea or nay, especially for an STI. Possibly with the bigger displacement, your runners should be a hair larger. Or maybe it would kick booty. I would think it might provide great spool and midrange with a little loss up high. Might be a great compliment to the STI as it seems to run out of steam up top anyway (from whay I hear). I could be persuaded to drive the snot out of your STI to confirm that theory. This reply could be longer, but I have to go get a beer.

San

 

The only reason, I believe, that the STI runs out of 'breath' up top is because it has a VF on it.

 

about the cams and even the head ports would prove worthwhile.

San

 

until the results of this thread come out

http://forums.nasioc.com/forums/show...hreadid=455046

San