He'll tell you that it is a MULTIPLE-ANGLE with curves between the angles and he won't tell you the start and finish angles because that's his trade secret. If you want to get in the ball park....it is a very wide spread multi-angle....like a 55-30. I ran a Doo race dept helix years ago in my 01 that was a 53/37 and it worked pretty good. Joe's QR11 is a VERY good piece though....you won't get the same results from a helix that just transitions from one angle to the other.