What is the max BHP you could possibly hope for using a 3" sport cat downpipe and a TD05 20G turbo?

Would the sports cat badly restrict overall performance?

Anyone done this?

 

Admittedly using a bigger turbo Litchfield used to squeeze 415bhp from their brilliant T25s using an MOT-friendly Milltek system and TMIC

 

I think Steve (Gimp) is running around 450bhp on his sportscat

 

As Jamie has said mate. I'm running max of 480 bhp (well made 482 bhp) with sports cat.

Normal day to day running on car mapped to 450bhp.

Has passed every MOT (not a dodgy one) since fitted to my car 5 years ago.