[Matthew_Armeni]

Did you enter everything into the calculator correctly? (voltage drop?). That setup is probably better for about 60-70 mph or so, but thats flat out, straight line, pavement running. Also remember that the calculator doesn't take wind resistance ino account, which really does come into play bigtime. And as far as racing setups it would depend on the track, but anywhere from 30-40, on the straight, and it would need to be a smooth straightaway, they get tossed arond more then the 1/8 scale buggies. A guy at the track I race at runs 3S and either the 5700 or the 6900 in his T4, it runs great, so I wouldn't worry too much. If you do want a lower kv motor the 4600 would probably be a better choice, or traxxas's 3500. But it's great to do a speed run every once and a while, especially when new people to R/C are around.