You might get 4 or 5HP across the board but don't think 10 or 11 because you will not get that. There is not one good dyno sheet that proves that yet, and I don't mean some spike when the clutch shifts. I pulled the cat and resonator off and could feel a difference in the mid range for sure, since the only dyno is 250 miles away I was not going to drive 500 miles to dyno it. So the question is, is 4 or 5HP worth 1000.00 to you? you may be money better spent putting a clutch in.