Video tape the launch from the side with an I-Pad/phone and replay the launch frame by frame. If you can see the tire driving down before the car starts moving you need to tighten the extension. You want the cars first movement to be forward. The compression for my car has always been an assomoter thing. If I can feel that it's too tight while driving through the pits, I loosen it up a tad. My car is more than 50% weight on the rear and is slammed to the ground though. I would tighten the extension from 5 clicks from tight the first time that you hit it. There really isn't a heavy shock to the ring gear foot braking. With a trans. brake the ring gear is hit and immediately wants to hit the ground.