is it beneficial to fit a cat back 3" system rather than a 2.5" system. is the turbo spool up any different? the car is a 53 plate sti with only a stainless exhaust as mods.

 

Any reduction in back pressure on a turbo car is good, but whether you would see any major difference between a 2 1/2" to 3" is debatable considering you still have a cat in place.

Go for a sports cat or de-cat to see the best gains (as well as a 3" system).

Regards,
Shaun.

 

thanks shaun.

 

anyone else fitted a 3" system over a 2.5" and noticed any difference.

 

I ran 325 BHP on a 2.5" system .......... I only moved over to a 3" system to get up to near the 400 barrier !!

I can't see any benefit in your case IMHO

Shaun

PS have you been to the "Swan With Two Nicks" in Lymm recently ??

 

errrrm, i dont think so why am i missing something