I think stage 2 would be more than ample for the turbo kids. If we're putting out more power than the stage 2 clutch can handle, the internals of the motor will likely be the next weakest point.

Something tells me stage 3 would be a grabby sumbeech.

For the stock folks, or people with basic intake/exhaust/tune, stage 1 would be best as drivability wouldn't suffer.

I still want hard numbers though.