Ultra4 Class Differences

This is just a brief overview of the basic class differences that race in ULTRA4. 
Please Note: If you are planning on building and racing a car, you MUST consult the rulebook for ALL requirements for your desired class! This page is just a brief overview of the class differences.



Ultra4 Unlimited
  •  These cars  are not limited on tire size, engine or chassis design, other than to meet the safety requirements for the class. Unlimited cars must have a transfer case and be able to be driven in 4WD. These cars can be straight axle, or independent front suspension (IFS). 
 Ultra4 Limited
  • Naturally aspirated engine size shall be no greater than 3.9 litres V configuration or 4.0 litres straight configuration. Forced induction engines shall be no greater in size then 2.0 litres. No boring or stroking of original engine displacement.  
  • Stock Chassis must be retained
  • Stock body must be complete. Modifications permitted but must preserve the look of the stock body.
  • Any engine permitted
  • Tyres can have a maximum outside diameter of 37.5"
  • Must utilise the stock chassis and maintain stock appearance
  • Any engine permitted
  • Maximum engine displacement is 1100cc.
  • No limits on wheels and tyres