Gearing and traction are both issues I've had to address as I try to run "commercial" type (1/32) cars on my home track. A lap on my track is about 45' and it's 1/32nd only with some very sharp turns.
I finished it with a marine high-gloss polyurethane that looks and feels bitchen but I just can't get sponge to perform on it (glue is banned). I've converted my cars to urethane tires from Paul Gage in Canada and have been happy with these so far.
With 64 pitch gears, I am as low as I can go with a spur that clears - that means a 7 tooth pinion and 39 or 40 spurs.