Knotty_

iTrader: (5)

As above, for my bug WRX. Turbo back ofc.

Is there much performance difference, and/or sound?

Thanks,

Knotty

B0DSKI

iTrader: (17)

If the car is standard then 2.5" is fine. I found going to full 3" on my STi lost some of the shove in the back when coming on boost when running the standard VF35.

allsop83

iTrader: (9)

What he says- 2.5 is better for standard power.

legacy_gtb

iTrader: (3)

2.5" is good for up to 480bhp ish before it starts to restrict, it drops where peak torque sits in the rev range and makes a nicer raspyer noise which is also quieter for getting on track.

I think im right in saying its the downpipe that needs to be a larger bore! but having that tapering from 3" to 2.5" at its tail is fine.