what does it mean by clutch slip?? what's power shift??

 

Clutch slip in a nutshell is when the flywheel is attempting to spin the clutch disk, but slips due to lack of friction. There are several things that can cause this: the clutch is not rated for the engine output, the clutch disk is worn, the clutch is not fully engaged, etc.

Powershifting is the process of upshifting without releasing the gas pedal. Some say that this makes you faster when accelerating in a straight line, but I've seen back to back runs and power shifting did not yield faster times. Not to mention, power shifting is probably killer on all drivetrain components.