Excel worksheet for some of my speed runs

[MetalMan]

I have to say that there is definately something wrong with your setup. In my Rustler, I have a Feigao 540 size 12s. When I did speed runs with 4s Lipo, the motor was only pulling about 40,000RPMs MAX at full throttle. I got up to 56.5mph... And that was with 25/87 gearing (or something like that). I am sure I could have gotten it to go faster, but the space I had was VERY limited (as in I have about 100-150ft. for acceleration, and 50ft. for braking).

That said, your motor on 12 cells should be spinning at about 56,000RPMs at full throttle. With high gearing and with enough space to accelerate to full speed, you should be hitting pretty close to 60mph. But if you don't have at least 300ft. for acceleration, you aren't going to do it. For the car, the difference between 50mph and 60mph is HUGE, and so it will take a lot more time to go from 50-60 than from 40-50 (air resistance). Also, if you run with a body, take it off and then run it. The body is actually more likely to slow it down. When I did my speed runs, I never ran with one. Another thing to check is your slipper clutch. For speed runs, you want it tightened down completely. Also, if your tires aren't getting good enough traction, they could be slipping from the enormous power.

Now, if none of this helps, than I am dumbfounded. The only other thing it could be is gears/bearings.