GTM Twin SC. How to not destroy my car?

Originally Posted by dmhenderson

600+ hp on the stock block? Laffo.
You'll put your eye out kid.
HO HO HO

(You are going to blow the motor)

So anyway, without building the motor I would not take it above 550whp. I stopped at 500 to be "safe":
-Oil cooler is a must. The bigger the better.

-I had massive traction issues (1 wheel peel etc) after the upgrade so I sprung for a Quaife diff and some meatier tires (275f/305r) and that solved most of the problem. OS Gaiken makes a better diff but they're noisy and require rebuild periodically.

-Your exhaust is fine but if you want better numbers, you will need something more suited to FI (free flowing)

-After 6 months, my stock clutch is still hanging in there but I can feel it starting to slip in 2nd on occasion so it's on the "probably needs to be replaced at some point" list.

-Get rid of your cats if you can get away with it.