TPR magazine did a pretty interesting header comparison test on a Honda B16. This is a good article. If you get nothing else from it it shows just how much of a difference that two different dynos will have. One set of tests was done on a dyno dynamics dyno and the other set was done on a dynojet. The differences were huge. If you're bored or interested click the link to see the article. http://www.tprmag.com/issue/10/10_b16_headers.shtml