bdebde, I don't think so. I have exchanged PMs with a couple of people that are running the 1512, and the desired rpm ranges don't change.

I'm not going to try to make heads or tails of anything. I believe that I have a 1512 2.5d coming my way in the next couple of days. My truggy, since I put it on a diet, doesn't weigh much more than a buggy. The 1512 should do just fine on the track. All I should be sacrificing is a bit of torque and I know that there is a bunch of that to spare with the 1515, so the 1512 should be just fine.

We shall see.