1)Engine had 280HRS. on it with the HO polaris kit installed (HO kit by the way worked great… my machine would run with the two seat 1000’s down the sand drags in Glamis )
2)Got the Aerocharger kit used and it needed refreshed… so on with the story
3)Ditched the aerocharger supplied fuel controller and went with Power commander V PTI and also swapped out the 3 bar map sensor for a 2 bar G.M. style map sensor for the purpose of the voltage resolution it would provide to the PCV. Incidentally the "temperature part of the PC PTI" that is used in there sales is purely a gimmick as there are no tables to allow for "temperature" compensated fuel mixtures.. This currently can only be used for Startup fuel enrichment and when to turn on Auto tune functions…. So don’t purchase thinking you are getting the greatest controller out there…not the case they need more R&D and better hardware/software to make our turbos work more better….
I spared no expense with PCV as purchased the AutoTune and also the LCD-200 display to make sure i "did it right".
4)Had the Water cooled intercooler plenum checked for leaks and welded aluminum bung on top for the trapped air (factory has it just tapped into the aluminum tank)
5)Added a coolant purge tank for the water intercooler (factory has it plugged off)
6)Used High quality silicone hoses for a water transfer and turbo connections (eBay is a good source for these) also used Header wrap anywhere i could to reduce heat transfer to the aluminum intake plenum… Once again eBay does well for this header wrap cost has come down to a cost that is cheap and reasonable
7)Used the orig Exhaust muffler for my first "shakedown" trip but soon realized the sound was too loud to deal with so I then cut up my SLP dual outlet muffler that was on the car for the polaris HO kit and began the addition of that back on the car….. That turned out great Nice addition…
8)Fuel injectors were the "yellows" that were in the aerocharger kit (gasoline) not E85)) but found that one injector was suspect in that one cylinder went lean and burned up leaving me with regret and why did i do this turbo kit…. I replaced both injectors with a set from 5 0 Motorsports (630CC set) there website makes it easy for the RZR community to buy injectors.. check them out if your in need of injectors.
First trip out and well the car was bad ass!! I was beating three new turbo XPT’s by a car length up COMP hill at buttercup dunes….. great feeling that the "old 900" still was bad ass…
The engine was stock compression 10.5 to 1 and 280 hrs with polaris HO/Stage II cams installed and pushing 6-7 PSI of boost at 14.7 seal level, and 91 gas
However as i said the cars bad ass life was short lived… I burned up a piston and not exactly sure how it happened (injector problem, Top compression ring end gap was lined up with the valve relief cut into the top of the piston (very thin distance from top of piston to the ring gap opening, detonation, Or THE UNKNOWN)
So on with the REBUILD….
engine now has:
1) 9.0:1 turbo specific pistons The only way to go as they are build to better deal with the demands now placed on the combustion chamber
2)ARP head studs now available to torque to 85# yes 85Ft Lbs.
3)New WEB cams "beehive valve springs" #81 seat pressure (stock HO springs 41# as i have read) This will allow higher boost pressures but moreover the bigger issue with the Prostar engines and stock valve springs is its easy to "float and drop a valve" the cam profiles other than polaris’s have steep ramps and could leave you walking back to camp…. and a lot of damage .. along with the cam story please realize that with heavier springs its mandatory to replace the cam followers (buckets) as thy are a soft metal and the 81# seat pressures will tear them up (I had this happen also……)
4)Aftermarket chain tensioner replacment (i used ALBA racings Automatic one that uses a yamaha auto tensioner and a a aluminum adapter ) NICE JUNK!!!! I did this due to the extra force on the cam chain opening the heavy bee hive valve springs…
5)Billet (K&T) intake manifold so i could add boost and not be concerned of the stock manifolds cracking and causing tuning issues
6)50 motorsports 630CC injectors as i mentioned
7) WEB CAMS #516 grind camshafts for turbo engines (small valve overlap) Valve overlap in N/A engines allows for a scavenging effect to help draw in the next intake charge… with forced induction overlap is not required and effectively pushes wasted charge out the tailpipe!!
8) Exhaust modifications : Didn’t care as i said with the stock muffler from aerocharger and modified my SLP dual outlet muffler to fit machine again….. along with that i was not happy with the fit of the exhaust pipe to the turbo inlet… Those who are aware of the two aerocharger header designs would recall the first design had a flex joint in the header to allow for thermal expansion and movement for the turbo housing that is mounted directly to the frame of the XP9 (good idea, necessary idea) the second design used a "donut gasket" and a solid pipe connection the header to the turbo housing,….. Not good in my mind….. so i fabricated a hybrid design I added a flex joint to the second design and we’ll its bad ass!!!! Now on to the O2 sensor location… I was not thrilled with the location of the stock mounted O2 sensor from aerocharger it was Post turbo and i understand the concept… its so the O2 sensor in not in a pressure environment however due to the donut gasket and other possible air leaks i chose to relocate to a more conventional location … Up on the header where the two cylinders combine…. This will allow a perfect place to sample the heat generated from the combustion chambers… So far so good pressure PRE turbo have not caused issues with sampling.
