Just to let you know, we would likely NOT be running Super Unlimited with the PDG GTM except for the center steer modification. This was done to increase fuel capacity and to make the car a bit safer by moving the driver to the center where the roof is higher, but if we didn't have to do that we could have qualified for a few different classes that would have been much easier to compete in. For the endurance stuff, we probably still would have been in ES class though. You should be able to compete with everything but the fastest sports racers in Super Unlimited with 630 HP. We do, and we only have a bit over 500...but if a real Grand Am car or Trans Am car shows up, it's another story. There ARE some pretty fast purpose built race cars out there. We end up running frequently with NASCAR Cup cars and although they definitely have a HP advantage and a tire advantage, we run with them and beat many of them pretty easily depending upon the track. You might want to look into the other NASA classes available as it is really nice to run close to someone else in times and that doesn't usually happen in SU.