I've personally had my Bamachip's custom mail order tunes, dyno tested by 3 different tuners..2 were on Mustang dynos, and the third was on a Dynojet..Each of the 3 tuners that did the testing ! told me that I'd be wasting both my time and money, as they couldn't guarantee they could squeeze any more power over my Bamachip's 93 race tune, even with any of their custom tunes on the dyno..That's how good they claimed Doug's tunes are ! You can either purchase a handheld programmer from Doug, that already has 3 of his tunes included ? or you can purchase the tunes from him separately (via e-mail) and then download them into you're existing programmer yourself.