No one seems to know yet what the xtz wet clutch will put up with over time.As far as 70 hp. to the rear wheels that should be 90-95 at the crank.And 70 at the rear wheels is only 15-20 more than stock depending on what or who's dyno you go by.I would think that it will put up with that.
As far as the dry clutch the only one I have seen so far is the comet 103 for the prowler.They are noisy but work pretty good.They have a 8500 rpm limit though.Lots of different weight and spring set ups available for them.The weights can get kinda pricey though.And the adjustable weights are pricey.Very easy to tune in my opinion with the cover off.Talking with a few snow mobile guys though that have told me the comet 103 is a toy really.But they did say they were better than what i had which was stock rotax dry style clutch.I have experienced huge gains with the comet and some other changes.Of course now that this one is almost dialed in they are coming out with a new one that is 100 times better than the comet i bought.
I will say one of the things i was getting wrong and did not understand was belt slippage.Belt slippage is why the rzr runs so good out of the hole.They are sacrificing belt longivity for the hole shot.Rzr's go through belts in the dunes if they are being pushed hard.It is funny when you go into these utv shops how many belts these guys have in stock for the rzr.The real cool thing is if you start making some horse power with your utv and you get the belt tension right to where you don't have much belt slippage how much more power gets to the ground.And the belts last much longer.And the clutch componets do not get burning hot.
I don't know if I would worry about the dry clutch yet if i was making 70 at the tire.I think I would try it first and watch the belt for wear,rubber smells,jerky starts that kinda stuff.Of course if it just does not have enough belt pressure it could over power the belt clutch set up and be on the rev limiter all the time.