GT headers or ported ones
 

Hi i have a chance of some gt headers with a harveys trick up pipe or would porting my standed headers and pipe be as good in terms of spool, bhp, torque ?

it depends more on your proposed turbo and spec???

I've just switched from ported with Harvey up-pipe to tubular with Harvey up-pipe. The outcome depends on what power you are running, over 400 usual route is tubular, under ported.

To give an idea I gained almost 400rpm of spool going from de-cat up-pipe and std headers to Harvey up-pipe and ported headers. I got to 440bhp on that setup, I've just switched to tubular + Harvey up-pipe and I've lost out slightly on spool (200 rpm max) but am getting the same power with .1 bar less boost.

If you want more info let me know and I'll dig out the graphs.

im looking at maybe vf34 if i can find a good one or sc38, so they wouldnt be much help at the mo on my vf24 ? what if i just the up pipe would that improve my spool ?

Up-Pipe would help spool, no question and if you're changing it you may as well port the headers at the same time.

At those levels tubular is likely to increase spool.

Alyn is the man in the know right now, it was one of his Harvey pipes I've just fitted!

so if im reading this right at my level now its best to fit harveys trick up pipe and port my standard headers and not fit the gt tubular ones

I have Ported headers with a h&s up pipe and with a bit of luck was a perfect match which I think helps bottom and mid range and at my power it works very well 352/340 on a vf34 which is not bad for a Bugeye WRX :nod:.
Headers were done by jaffacake-tone.

Stick to ported and trick up-pipe sub 400.

are ported headers somthing that we can do or is it a specailist jobbie?

You can do the basics, but porting the collector(s) is not easy.

best left for the pros then! just something worth concidering with the vf35! and will look into the up pipe, does the standard up have a cat in it?

There's a small pre cat in the uppipe on the newage wrx, but only up to a certain year I think. I have a feeling the late blobs and hawks didn't have it.

All STIs have a decat uppipe as standard.

Is the up pipe hard to fit with removing the turbo ?

Can be done!

new-age 2.0WRX cars 2001-2005 have the pre-cat in the up-pipe as std - nothing else does

Thanks Alyn, knew it was something like that :)

cheers!