[MetalMan]

I don't think the 12s makes for a good comparison right now. The rear endbell is beaten up, and at one point the front bearing seized and I replaced it with a 5x11x4 (needs 5x11x5) bearing and a 1mm washer. It sounds different now, so I'm sure it isn't running like it used to.

The 4600 is geared with an 18/87, where the 12s would be geared 22/87. At this voltage the 4600 is spinning at about 63,000RPM, which is a ways off from the point of highest efficiency. The 12s would be spinning at about 42,000RPM, much closer to being most efficient. That said, I've recorded the temp. on the 4600 up to 200 deg. before I stopped, and it has ranged anywhere from 150-180 for other runs. This is all on the street using Proline Road Rages, and with these tires I am able to get wheelies (before using them I didn't know street tires could hook up so well).

I may have to try a 16t pinion and see if that will keep the temps lower no matter how hard I drive it.