Getting a GTR with catless downpipes and I’m sure it has a tune, any ideas what’s the HP level, I believe a typical stage 1 is around 50-80 HP but when you throw is a catless exhaust how much higher can this be? +100HP??

Exhaust is not going to boost that car by much as it’s a pretty free flowing design stock. What the tune does it’s not so much give you peak horsepower, but gives you throttle response which is ridiculously better than stock.

I have a gtr with downpipes and stage 2, makes 655 on dyno

I assume that’s crank horsepower not wheel?