[bxracer69]

I have the official rules:

2006 DESIGNSERIESTM BUILD RULES
Under each required criterion, XGR mandates certain measures.

GRAVITY RACERTM DESIGN RULES
 Weights and Measures
 Max volume of 9' x 4' x 4'
 Max weight 350 lbs. car and driver.

 Stability
 (4 wheels min)

 Performance and Handling
 Performance and handling to negotiate up to 3mile-long courses with sharp turns and road gradients up to 25% Optional for Hill Climb: Ability to climb hills unaided (see Energy requirement below.)

 Energy
 Gravity is the only source of energy to be used for the downhill races. No stored sources prior to race (must be proven to race officials). No driver input externally during the race, downhill or uphill Optional for Hill Climb: Capability to store emission free energy on each downhill run for use only during a return trip uphill as far as possible. Pit crews may be used to reverse direction and position the car at the finish line, but thereafter unaided for the start of the hill climb. All stored energy must be completely dissipated before starting another race downhill.

 Driver Safety
 Driver head protection through the use of a full racing helmet
 Appropriate safety harnesses and/or belts
 Engineered rollover protection (above helmet)
 4-wheel brakes

 Racing Safety
 Mandatory Braking and Steering test to be completed to achieve race eligibility
 Optional: Adequate measures taken to prevent wheel interlock during side-by-side racing

XGR Teams will be required to demonstrate driving, performance, and safety proficiency prior to race day. XGR reserves the right to amend the build rules as conditions demand and maintains the right to preclude teams should there be any question of safety.