Jagged X runs stock engines. We did run Kroyer built 900's in our old 900-4 up until to mid year 2013, but then went back to the 94 hp stock 900 H.O. engine and did really well with it. We did this to improve drive train reliability and the includes everything from the clutches to the CV joints. I would bet that our old XP900-4, full of fuel, tools driver/co-dog weighted around 2550. The new two seater is lighter because it is a...two seater and was built more with weight in mind.
I would say, let the turbos race if there was not another option. But there is and ALL of the Can-Am teams are currently using this N.A. option. So I really don't think I understand the 'let them race' mentality. Who is them? Nobody is racing one and it would likely entail a team building an entirely new car to race one. Cory and I discussed a while back about whether it should be 'legal' for RZR guys to put a 1000cc engine in an already build 900 chassis. We both agreed that it wasn't the right thing to do because of the engine swap rule and obviously a 1000cc engine didn't come stock in a XP900. So using the same logic, it would now require a team to build a completely new Mav to race a turbo, since engine swaps are not allowed just like they were not for RZRs. So there is no 'let them race.' It gets back to the more important issue of what the rules should be proactively. Let's make them open enough so the OEM's can grow into the rules instead of BITD/Cory having to react to every OEM nuance. Flame away!