This brings up an interesting point of discussion: would it be possible to move the center of mass during the run of your vehicle? In the ready to run position, Id estimate wanting about 90% of the mass in the rear, but after the vehicle has descended down the ramp, it is more advantageous to have about 60-70% of the mass in the rear to prevent significant understeer and to aid in uniform braking. Perhaps it is possible to actually have the center of mass MOVE during the run. This could potentially be done near the end of the run (after 6-7 meters have been traveled) as a means of reducing vehicle speed. I envision a simple string wrapping around an axle after a certain distance has passed that moves the center of mass forward.
Food for thought. Id be interested to hear others' perspectives on this.
Legality aside, this seems a bit complicated from a technical perspective, because you'd need to have some sort of latch that starts off closed (otherwise the mass would simply slide down when in the ready-to-run). I think it definitely can be done, though. (also I don't know about the legality of this, but could it perhaps hit part of the ramp on the way down that opens the latch? Even if legal, I'm not sure it would be viable because it would take out a large chunk of momentum if not executed very well down, and have to be able to accomodate the dowel, which would likely mean assymetry, in which case any imperfection would mean the car could slightly swerve, causing some major accuracy issues)
The other issue is how much friction the moving mass would have. I wonder if you could build the whole vehicle around a linear slide as a chassis.
IDK how rational this is, but I think that much mass shifting on a vehicle should be pretty scary. OTOH, it would be pretty epic lol.
These thoughts are not fully fleshed out but I'm sort of sleepy, so we'll see what sort of glaring mistakes I've made tomorrow...