Good debate, but I disagree. First off you can easily take a Terex up to nearly 800cc and stay within the rules. Secondly a Terex is an OHC four valve motor that even at 750cc can make big power. Look at the Lucas races as an example...all under 800cc. If power was the issue then the 1000cc Cats should have cleaned house; and yet they haven't, didn't and likely won't.
Did you like my idea of a 800cc and below class and a 1000cc class...plus sportsman?
If we can get BITD, SCORE and SNORE (plus others) we can continue to grow UTV racing.
I agree with Bajaxp the rzr's can not keep up with the teryx's in Lucas oil offroad and they are both under 800cc. Lucas oil is allowing the RZR'S to be 50 pounds lighter than the teryx to help them compete. I think the teryx motor is a much better platform to build up. Stock vs stock i agree the RZR has a definite advantage but after modifying i think the teryx is pretty good at 800cc even if it weighs a little more.
I also think that the weight limits should be agreed upon and checked without driver and co driver to make things more fair especially in races where there are driver and co driver changes because you could weigh in with your heaviest people. I would like to see the cars from every manufacturer be able to compete in the same class with weight regulations to keep the class competitive depending on cc's you wanna run.