The problem is, that does seem to be inherently slower. Torquey motors don't spin as fast, and generate less heat. I also can safely say that, at least for 1/10 carpet off road, a torquey motor will always be faster as newer carpet tracks have incredibly short run ups to jumps and between corners. You need the low end power to be fast in those. That's why the newer Tekin SpecR2 motors are much slower and more powerful. That all being said, I miss by old SpecR motor that had no torque and spun to the moon. I had one in my wheeler and it drove like a mod car. So fun!
17.5 is pretty much full beans everywhere, but a 13.5 car with a spinny motor would be so fun.