This is the second racing map a have built. It includes multiple jumps with the sheild doors. The first lap takes up half of the map Rat's Nest. After you go through the mancannons and go through the lap counter, you go around the other half. Then (After another lap usually) You will have to make a left turn and go through the middle of the map using sheild doors as shortcuts through some of the more open areas.
Pics:
Start
First jump
Cheat proof system
First ramp
Second Ramp
Later
Example of jump
Extra
Also download the Race :5: gametype to help with the map, or use your own settings with 5 laps.