SHR 860
I will make this as objective and unbiased as possible. I can respect Idaho Slims post. I have owned a SHR 860 and Big John builds a very solid kit tha is a very consistent performer. I now own a turboed xp...same chassis as the 860. The turbo has been a labor of love as there was no one out there that had refined a kit for the XP at the time( 3 years ago ). The concept of a turbo kit utlizing carbs is a fairly straight forward design. It is all the little things surrounding the kit that will make it perfom the way it should. Ie clutching, fuel pressure and blow off signals, charge tube sizing, cold air intake, functioning exhaust valves, did I say clutching.
With all this being said at the end of the day it is physics. 170 hp is 170 hp....230 hp is 230 hp ( depending on boost levels) and that doesnt take into consideration corrections for both NA and boosted applications as you rise in elevation. 230 un-rideable ponies, ie ...no bottom end ( improper clutching, jetting, signal references, etc) is no fun and will were you out....and not to mention the 860 will spank you for the first 100 yds. If you have a rideable turbo set-up..ie proper fueling, signal references, clutching, etc you will have a system that works together in and out of boost and it will be ridiculous.
So, unless you have some mad tuning skills from clutching all the way to fueling and where to pull signals,making your own turbo kit and having it run properly will be a challenge.
If you want a turbo for your xp,and you ride high elevations,i would not hesitate to call Rick at peak power sports in Aurora, CO. He is a wealth of knowledge, builds an affordable kit, and will more than likely also sell you components if you choose to make your own. I havent worked with turbo boyz but have a friend that is also a snowester and has had good luck with them. He also ran a big bore prior to his turbo kit and would second my opinion.
If you ride low elevation and/or live out east Gus Bohne would be a good choice. He also is a wealth of knowledge when it comes to 2 stroke carbed turbos.
If you want a pull the rope very consistent solid performer that will out perform most sleds on the hill Big Johns 860 will definately put a smile on your face. John is also a wealth of knowledge when it comes to clutching weather it is NA or turboed.
I hope i dont offend anyone with this post as i have tried to relay my experiences and opinion for what its worth.
Good luck