In case anyone ever wondered about putting a turbo on their RTV1100, I've had my turbo on for about 2 full years now. It's not really any faster, maybe 2-3 mph, but it gets there faster and will hold over 20 mph on the road going up steep and long inclines.
I've not noticed any difference in my oil when I change it. In other words, it doesn't look blacker than before adding the turbo. I've never had any over-heating issues, oil consumption issues or, acutally, any issues at all. My RTV almost never got used the first year. That "throw you through the windshield when you let off the throttle" pretty well prevented my wife from ever wanting to drive it and the same went for my kids. I think I installed the coast valve (original coast valve on eBay) a month or so before the turbo kit. After the turbo and coast valve, it gets used quite often. I have a special made toolbox in the bed just like in a pickup and I'm always using it to go work on something around the property. The toolbox is full of tools and the rest of the bed is generally filled with building materials. The tailgate makes a good makeshift work platform.
At my larger parcel of property there were several places my RTV900 could not get to nor would the RTV1100 (stock) because there were several long and winding hills that were really steep and roughly 100 - 150 feet rise in elevation. The addition of the turbo made this climb a complete non-issue. There is now no need to try to carry too much speed around some corners to make the climb after the corner. With the turbo on the 1100, I can easily pick up speed as I encounter these hills in 4X4 and, if needed, step on the rear diff lock. Now, if I know I'm going to be going up those hills, I just lock the rear differential when I unload. It's not like I'm worried about leaving marks in a lawn.
The turbo was relatively expensive, but I feel it was definitely worth it. The RTV1100 is actually quite heavy and the turbo makes the engine a good match. When I was installing the turbo I was pleasantly surprised that all of the cooling and oil supply and return lines were already made into the RTV1100 engine's block. All I had to do was remove the plugs and install the turbo lines. In my mind, that almost makes it a sure thing that this particular Kubota engine must be offered in some form with a turbo from Kubota. If my memory is right, I think the $1600 spent for the entire turbo kit and coast valve were well worth the money. We use the RTV relatively often now and I have no desire to own anything different. You can count this as my 3 year ownership review if you want. Except that crappy weld on the door frame, which I simply fixed and rewelded both sides since Kubota clearly wasn't going to do shit about it after I hounded them months about it, nothing else has broken and I've only done normal maintenance.
I would recommend one after my 3 years of owning one, but I'd highly suggest checking out the door frame welds on the unit before you buy it. It's too late now, but if Facebook and YouTube was as popular then as they are now, I think I could have gotten Kubota off their dead asses and made them fix the flat ass shitty welds on my door frame. I feel they owe me $300 for my time and labor to fix their piss poor workmanship that did break as I said it would, yet Kubota simply opted to ignore me when that happened. Rather than park it for months, I just fixed it myself. Hmm, I still have all the pictures....maybe I ought to put a video on YouTube about Kubota's piss poor workmanship on RTV welds and get it to go viral by having all 1200 friends or so I have on Facebook view it and have their friends view it. I've noticed that companies don't seem to like making the evening news due to a viral YouTube video pointing out their screw-ups and refusal to make good on fixing them. Obviously I'm still a bit chapped about Kubota forcing me to fix their piss poor welding job. Otherwise, it's a great machine. I just made a mistake by not taking Kubota to court for failing to abide by their own warranty and making me fix their problem. Oh well, live and learn.