Originally Posted by the shreksta

would a set of gt spec headers really alter the sound of the car? its the only thing thats different.

Originally Posted by HonestIago

I've had the following exhaust setups:

1. MY00 UK Turbo (OE headers throughout):
a) standard DP, 2.5" non-reasonated centre pipe and the original Prodrive backbox
b) standard DP, 2.5" non-reasonated centre pipe and a Ninja 2 backbox
c) sports cat DP, 2.5" non-reasonated centre pipe and a Ninja 2 backbox

2. Version 6 STi:
a) GT spec headers, de-cat DP and 3" Apexi N1 system
b) GT spec headers, sports cat DP and 3" Apexi N1 system
b) ported OE headers, sports cat DP and 3" Apexi N1 system
d) ported OE headers, sports cat DP and 3" Blitz Nur Spec system

Thoughts:
1. a) Pleasant but far too quiet (a de-cat with this system might have been nice)
b) Lovely - just what I was after in all honesty!
c) A slight(!) improvement over b)

2. a) Obscenely loud and raspy...embarrassingly so! Really didn't like the GT spec header sound.
b) Moderated a) slightly
c) Huge improvement, generally very nice but lacking the lowdown burble of my previous car (sounded better further up the rev range though!)
d) Very deep burble but annoyingly loud, boomy and intrusive - nowhere near as bad as a) or b) though

It could just be me but IMO, based on my experience, 2.5" sounds nicer than 3". With the right system you can get a lovely low down rumble that's loud enough to sound good and get some looks but without being embarrassing or off-putting on longer runs.