Ok, have you TOTALLY missed the concept of 1/4 mile racing? This means no running start. How fast does it do the scale quarter from a dead stop? I feel ya on the traction problem. The sandpaper may wear out those grips of yours, I use spit on mine.

I'm impressed with the top speed of your car. My 3cell zap goes from a dead stop in 1.9 seconds. You must be running a higher rpm motor than me, cause I get about 8mph with red gears. My quad cell Epoch only goes 10 mph. Did you check it on a treadmill, or just a bit of stopwatch guesswork? A tenth of a second is hard to see with a stop watch in hand. When I calculated my times, I used a time counter on a digital vid camera in super slo motion. See if you can borrow one. I would love to see the car that waxed my Zap.
Good job, man. I gotta do a 4cell mod now too. I feel my testosterone elevating. Grunt, burp, fart...