STi Backbox - info wanted
 

Hi all,

I have just bought a MY00 classic wagon. The back box has been modded, has a 3 inch diameter and is branded STi.

Looking into it with a torch, you can see right up it to the back. It seems to simply have only a perforated 3" tube in it (sweeeet!).

Anyone know from the description what type it is and what sort of power gains this would normally dish up? I really can't complain about the performance of the car, but I have no frame of reference as it's my first Impreza.

Looking at the dyno site, standard UK cars start at around the 230bhp mark and go up to around 240 if you are lucky. Would it be safe to assume 240bhp would be about right for my car?

I'd like to dyno it one day, just to know for sure :)

Sounds like the exhaust from an STi (or possibly P1) car. The exhaust was fitted to these cars as standard, not sure on power gains above the standard twin peashooter, but certainly is a better sound!

As standard, the figures you have quoted sound a bit high! A standard UK car (factory spec) supposedly put out between 208-215bhp (dependent on year)

Just going on the Dyno link at the top of this page. Mines a MY00 so is supposed to be 215 odd, although I keep hearing (even from the dealer) that these figures are conservative. The Dyno numbers seem to back that up.