Speed on it is great.
Faster than my 4.5v watch battery boosted bit (which makes my 1.0 faster than a 3.8 but with more torque
) Can't use it for track racing though, as the overly weighted top causes it to tip on turning. There were only a few people dragging, unfortunately. I think there were a couple 3.8's and that was about it. I didn't see any major mods, but I could be blind. My race-lightened Skyline was running stock 1.2v setup w/3.8 motor. It uses the chassis I use for my RX-7 (4-spoke rims, I cut out the other 4), sanded chassis to lose a little bit of plastic weight, and the body itself is modded to sit lower (front and rear tabs), sanded out inside so the thing is more brittle than a saltine cracker, and windows cut out. No spoiler.
Also, I was running the zip-zap radials (the ones with the funky tread pattern that looks like a real tire) on the rear to avoid rub, w/orange bit char-g gears.
The sanding on the skyline was mostly done so that I could paint it without truly adding any weight
I'm going to have to buy another 45mhz booster/chassis because out of 4 chassis, I only have 1 that actually works, and even it has a broken rear tab (the others have various things, such as broken battery tab, yes I tried resolder, didn't work, broken front and rear tabs, broken front tab and battery slot, etc. So, soon as I get a booster and a gear set, I'll see what kind of times I can pull out of it. With all these broken chassis lying arond, I kinda wanna make an AWD Bit..