fill me in on spoolup, and wastegate issues. just put on a 4" exhaust and someone mentioned that i should notice faster spool??? thanks in advance

 

Spoolup is how fast the turbo builds boost. The wastegate releases excess boost.

You won't notice much of a change in preformance from just an exhaust change on a stock truck.

 

With a new intake AND exhaust including a four inch down pipe you will notice a much quicker spool up than with the restrictive stock systems. By un-restricting your intake and exhaust you can move air much easier resulting in building boost much easier and faster.