cookstar

iTrader: (6)

Hi i have complete H&S decat system on my 02WRX, i believe it is a 2.5 ince bore throughout.

My question is... what would be the benefits of having 3.0 inch bore and are there drawbacks?

Thanks

Cookie

shifty (chris)

oi oi m8ty 3 inch may give a little more but u not notice prob about 2bhp may not give any change but thats wot the bloke told me when i had my custom made done he said the 2.5 is better but other people may think differant

DaveW

The 2.5" system will start to become a restriction above about 330-350 bhp after this you would benefit from a 3" system.

On your car with a 3" system you may notice higher power at higher revs, but less torque lower down the revs. So if you find a 3" system you want then don't be put off buying it.

Dave.

V5-APS

iTrader: (1)

What if the downpipe is 2.5", but the exhaust is 3"??
Any benefit having 3" over 2.5" in that scenario??

jasonius

iTrader: (1)

On my 05 wrx I have 2.5" throughout and after remapping the low down torque and turbo spool up are fantastic. As said if you're looking to go much beyond 300bhp then you may want a 3" system, for me I'm very happy with the response and drivability and ~270-280bhp I have..!