Since fitting my Supersprint 70mm race system on my mk1 172 which does away with the cat ive noticed that i no longer get the power surge that you get at about 4500rpm.It definetley sees to pick up alot faster from lower down the rev range but you dont get the boost at 4500.Im not saying its slower im just wondering what the difference is,maybe its because its givin it more lowdown power that the change at 4.5k is not as noticable.I have since put a r-sport ecu and Hillpower IK on it but its not made the 4.5 surge come back.
Dogmaul did you notice this when you had the exhaust on your car?
Cheers for any help.