Shredders

Here's my achievement guide for this achievement. It's done fairly early on, on the 540 Indy 540 INDY level.

1. On the 3rd and/or fourth jump, pick up speed before hand by pressing forward.
2. Hold the right trigger, right analog stick to the right, and RB just before going off the jump.
3. Let go of the right trigger to go off the jump, only holding the right analog stick, and RB.
4. A 540 is 3 half rotations. You should be able to get that fairly easily, but hold x to retry if needed.