Jump design

[mole2k]

Well basically im planning to build a few new jumps for my club as the current ones we have are a bit boring and easy to jump.

My idea is initially to build a tabletop that can be fairly easily stored away. We have the entire bottom of a stage to store stuff so as long as it can be packed relatively flat and slid in its no problem.

Dimentions is the main part of my query. For a tabletop what do people feel it should be in width/length and height for the tabletop bit and what sort of angle on the ramps. I have some plans drawn up for what the general idea I have in my mind is that it splits in two so that it folds to half width and full length then the legs also fold down. Ideally I would like it modular so I can have a straight table top or have the up and down ramp at 90 degree's to each other.

Im more concerned with what angle to have the ramps so they arnt too steep to cause the car to bottom out and bounce off the jump upsetting its flight or too shallow so you dont really get any airtime from it.

A picture of my concept for the tabletop


I'd just really like any pointers as to problems anybody else has encountered or any design adjustments you think would improve it.