Eversince I upgraded my trans after my live tuning I'm having major surging especially when it shifts to 2nd gear and the converter locks. It also does it in 4 high when racing. But here's the weird thing if the road is wet or when I loose traction,it shifts perfect every single time. Only when i have good traction with no tire spin it surges a lot on the shifts. Any ideas? Could it be in the tuning and things change since I have a stronger converter.

 

Could you be over powering the turbo? When the tires are spinning on the wet surface, you are not putting as much of a load on the turbo as you would with the tires on a dry surface. Just thinking out loud.