I'm going to either get my OEM Headers ported or fit a aftermarket set at the same time as getting my APS CAI fitted.

What sort of experienes have people had with either ??

Looking at GTSPEC2 Headers which i've been led to belive are a good set up.

 

I think the general concensus is a Harvey ported OE set is probably best for most applications. The now defunct Scooby mag had a problem with the GTs - though yours may be an improved version.

 

I got GT Spec II replica headers on me 03WRX, ceramic coated, break my bank dogs danglies! LOL
And i now wish i had saved hundreds upon hundreds and got my oem ones ported.
From a man who knows, save your money, port the oem, and gain more boost earlier in the rev range, etc, etc.
OR like me, spends nearly a grand and get **** all worth it from it and get the boost come in at higher revs, taking your power so far up the revs it defeats the object.
And yes, i am bitter and twisted about it! As crabbit as a scrap mans dog to be exact

 

LOL straight from the horses mouth so to speak. I've been quoted £300 just to ceramic coat the GTSPEC ones & told that the boost threshold will be 300RPM higher.

I'm more after increased midrange rather than top end so thats a good vote for porting the OEM ones

Just means i can spend the money on summin else lol

 

Good man! Now who wants to give me lots of money for my used headers? LOL.

 

After more advice it looks like it's gonna be porting the OEM headers then. Unless anyone can convince me otherwise

 

Port em

 

what benefits can be had from porting oem headers? does it give more power/torque or just a smoother delivery of the power?

 

Mine are ported and i'm actually surprised how quickly the 18g spools.

 

Just what i've heard Gaz, and the 18G is what i'm thinking of for the future so cheers

 

im on oem potrted headers
jim

 

The GTSPEC headers work no question.

The graph below illustrates OEM ported headers vs GTSPEC GenII headers as recently tested on our MY05 STi running the Forced Performance Green turbo.

1st run (red) is FPGreen on OEM headers at 1.5bar to the redline
2nd run (blue) is FPGreen on GTSPEC headers with no map changes to boost control, consequently it only runs 1.38bar to the redline - same power, less boost
3rd run (yellow) is as run2 but with map changes to hold 1.5bar to the redline




Still think ported headers are the way forward

 

No doubt the GTSPEC works better thn the original Ported headers it's just i'm a tight **** and can spend the extra money on summin else Zak

 

Would like to see that kinda comparison on my WRX Zak! I bet it wont look like that when compared to ported oem ones.
That is what i was saying, with regards to my WRX and not an STI.

 

No worries Bodski, just wanted to illustrate the difference with evidence rather than speculation.

Madass, unfortunately the WRX lacks the adjustable inlet cams of the STi which can be used to improve spool up

 

That's weird, because when i posted on the GB for the GT headers, i was told it was not worth it if i liked it to spool earlier.

No-one contradicted it then.

Anyway, gonna stick with what i've got. Money is going on suspension not power.