Leeroy

I have a standard MY06 2.5Sti and have just acquired a prodrive back box and centre section from a bugeye PPP Sti. I want to get some of the burble back and hopefully a bit of a performance improvement!

My question is regarding the resonated centre section - is it worth swapping my centre section for the one from the older PPP'd Sti, or just sticking the b/box on my current pipe? Is there any difference between the two, other than the older design having a lot smaller resonator?

Cheers,
Leeroy

whitepilgrim

Had the same dilema a week or so back was advised that the back box alone wouldnt make much difference regarding burble on my05wrx

Leeroy

So presumably there must be some benefit in switching to the older centre section?

Luckyscoob

iTrader: (2)

Done the same thing myself, and can confirm that by just changing the rear box does give it back the flat four sound, but oddly enough not on tickover. Once you get the revs over 2000rpm, everything is back to normal tho'

Leeroy

Lucky,
When you say you did the same thing did you also replace the centre section?

Leeroy

Luckyscoob

iTrader: (2)

No, just the back box, and to be honest, for me it gives just the right level of noise. I may get a prodrive centre section later, but as the car is new i'm going to leave it alone for the time being. I would try the back box first, you may find it gives you the noise you want.

Leeroy

I fitted the backbox this afternoon and it has improved things once on the move, but as you say you wouldn't tell at idle (although saying that it is more bassy when you fire up). I wouldn't say the burble has fully returned though - although i'm comparing it to my previous 2 de-cat classics!

I didn't bother with the centre since the old one still has a resonator and is mild steel and a bit rusty. I think i'll leave it as is for the moment until i can get hold of a de-res centre!