Some dosey chuff has spent alot of money on the 97 WRX I have bought.

New ECU, Freeflow Downpipe, Up-pipe etc


And then they have fitted a standard system from the downpipe back.

I mean, its like 3" to 2". Now thats got to be very restrictive in my book.

So how much BHP is it losing over having a straight through centre and decent backbox?

 

Not as much as you might imagine, is it not 2.5" standard?

It is also going to be quite refined. If I could only change parts of the exhaust I would start at the downpipe and work back.

 

Thanks John!!

I have measured the bore and it does seem to be a little smaller than 2.5". I was thinking that the ECU must have been set up with a full 3" system fitted and that the car will not be running correctly without one. Going to change the centre and backbox anyway in the near future.

Any recommendations of exhaust? I was thinking of the ScoobyMania 3" centre with resonator and their backbox, V2 is it?