MPI 850 Turbo: First Ride Impressions

Hopefully by now everyone knows my story. Been riding Yamahas since 2009. Turbo Nytro, Supercharged Nytro, big boost turbo Viper. Last year decided to make the transition from boosted 4 stroke to 2 stroke, and picked up 3 brand new 2017 Ski-Doo 850s. 2 SPs and 1 Summit X.

As a general rule I try NOT to do mid season major installs as I all to frequently seem to run into problems and I HATE having to rush through an install because our season is SHORT and I don't want to lose any days of riding to a sled torn apart in my garage.

My son on the other hand doesn't see things quite the same way as his father does!:face-icon-small-hap So he went ahead and got himself one of the new Turbo kits from MPI a couple weeks ago and decided to bolt that sucker on his new 850 and start living the life of Boost once again.

While I also plan on installing an MPI Turbo on my 850, I am trading out my 2017 Summit X for a new 2018 Summit X with the new SHOT starter system on it, so my install, which WILL BE my normal HIGHLY DETAILED STEP BY STEP install and review, will have to wait till my new sled arrives in Late Summer or Fall. THIS post will be almost exclusively a RIDE REVIEW for those members who are sitting on the fence considering whether or not to boost their 850..

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The MPI Kit arrived at our house in a single large box, VERY well packed and ready to go. The kit does NOT include a printed manual, but a link to a full color PDF document on the MPI website. First thing we did was to download the PDF and PRINT IT OFF so we could have the paper manual in the garage to follow through step by step.

The installation itself was pretty darn straight forward. They estimate about 6 hours for a professional mechanic who has done this before, about 8 hours for your above average Shade-Tree snowmobile mechanic and probably 10-12 hours for your hobby enthusiast that has never torn his sled down before. We used every minute of 12 hours.

Only one specialty tool was required for this installation, and that was to crimp the fuel lines. Otherwise just normal tools for everything else.


But we did find we "wanted" a little more heat shielding tape than was included, some extra Zip-Ties, a little Loctite. Do make sure you have some replacement coolant fluid, or a CLEAN container to drain your coolant into so you can recycle it.

As I said the installtion itself was pretty straight forward, just follow the instructions in the manual step by step and it will walk you through the entire process. We started friday afternoon, and had it wrapped up by Saturday afternoon. We could have had it done late friday night BUT..

You MUST install either an AFR Sensor or an AFR SENSOR PLUG into the Turbo Housing. This one item IS NOT INCLUDED with the kit! You can order an AFR sensor from MPI when you purchase your Turbo Kit, or order it from any automotive supply shop. Because we did not have this on hand, we had to go hunting for it for several hours on Saturday. You know in advance, so you will NOT have the same problem we did!

Once the kit was bolted on we wheeled the sled out of the garage and fired her up for the first time with NO problems whatsoever. She started on the very first pull and sounded GREAT! But since it was already late Saturday afternoon we were not able to take the sled out to the snow and test ride it.
That had to wait till the following weekend.

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Weekend #2.
Loaded up the sled and headed off to Island Park for a shakedown ride.

Ran the sled down the trail about 2 miles or so, stopped and checked everything closely. Other than a little smoke coming off the turbo from the cutting oil burning off everything seemed just fine.

Continued on down the trail getting a feel for the sled for several more miles and stopped again to check the install once more time. This time we noticed the col-lent was BOILING in the reservoir. The engine temp gauge showed it was well within normal temps, but we could see the bubbles in the tank. So we SLOWLY depressurized the reservoir tank and then rolled the sled over and "Burped" a bubble out of the cooling system that we had inadvertently introduced when we drained the system during the turbo install. We added water to the system to refill the reservoir, and all seemed good.

BUT..
When we rolled the sled back onto the skis, I heard a very distinct TINKLING sound come from the clutch. Opened up the side panel and found that the two upper bolts holding on the Airbox had come lose from the threads and fallen out. Turns out all 4 of these bolts MUST BE LOCTITED into place! Failure to use Medium Blue Loctite will almost certainly result in the bolts back themselves our due to vibration.

This is a CLASSIC example of being in a rush to get a major project done and NOT taking your time to pay attention to every single little detail!.

With the two bolts out, the airbox lose, we towed the sled back to the trailer and brought her back home. Stupid Mistake, but VERY happy absolutely no damage to either the Turbo Kit nor the Sled was done!

Once back in the garage the fix took about an hour and the sled was once again ready for a good shakedown ride. Yesterday, Saturday March 18th it was my turn to take the sled out and shake her down as my son was previously committed to something else for the weekend.

We took 3 sleds with us for comparison purposes.

a 2015 MPI Stage 2 Yamaha Viper making apx. 220hp
a 2017 Summit X 850
and the new MPI 200hp 850 Turbo.

The two 850s were pretty much identicle for all intents and purposes engine/power wise in stock configuration, so I thought they would make a great side by side comparison for Boost and no Boost. The Yamaha came along for comparison to what I have been used to riding for the last 6 years.




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IMPORTANT NOTE:
Yesterday's ride was done with STOCK CLUTCHING!
The MPI Turbo REQUIRES CLUTCH adjustments to achieve anything even close to optimal performance. Clutch Weights are NOT part of the MPI Kit, and the determination of EXACTLY how to set up the clutch for the specific altitude and type of riding you will be doing is LEFT UP TO THE CUSTOMER. MPI will be happy to offer suggestions, but in the end, YOU make the final determination. This week we will add weights to the clutch and get it dialed in now that I have a very clear feel for how it runs.

The net result of having NOT adjusted the clutch was that I had to be VERY CAREFUL to control the engine RPM not to allow it to exceed 8,000rpm. And that meant I NEVER exceeded 30% throttle the entire day!
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So let me tell you about how this beast runs!

HOLY FREAKING COW!

The 850 with the MPI Turbo Kit on it is a beast.
At about 5,800rpm you begin to feel the first twitches of boost.

At 6,000rpm you know the boost has begun and the engine is starting to come to life.

At 7,000rpm you are fully into the boost and the sled is pulling STRONG and HARD

At 8,000rpm your getting 100% power from the turbo and there is a dramatic change in tone/pitch of the exhaust sound. And it is a SWEET SOUND! I don't know nearly enough about whats going on inside of this engine to offer explanation of why the huge change in sound, but the second you hit 8,000rpm, EVERYONE in our group could hear the sound change. And for the rider the moment we heard that sound we knew we were at our self imposed RPM limit and had to back off.


In stock clutch configuration, none of the three riders ever exceeded 33% throttle travel!.

Engine RPM response with this kit was nothing short of TERRIFIC.
I did not feel any noticeable "Turbo Lag" at all, and generally felt that i was pretty much always riding with some degree of boost unless I was just crawling or doing very slow precise maneuvers.


One of the FUN things we discovered was that the MPI Turbo 850 would outperform the Stage 2 Turbo Viper! The 850 engine is a GREAT engine in its normally aspirated configuration. I think anyone that owns one of these sleds already knows what a capable and FUN engine SkiDoo came up with. But with a few pounds of added boost, this engine positively EXCELS at putting a smile on your face.

This was my FIRST TIME ever on a boosted 2 stroke, so please understand the totally unexpected surprise it was for me at how well this engine worked under boost. This sled just constantly impresses me and everyone else who rides it. The 850 is a GREAT SLED in it's stock OEM configuration and has plenty of power for normal mountain riding. But JEEZ, bolt on this turbo kit and HOLD ON. It transforms this from a great sled into an absolute "E" ticket ride up the mountain and through the trees!:face-icon-small-hap:face-icon-small-hap

It was an absolute freaking blast to ride all day long!

I had NO engine issues or problems with the sled. I had NO trouble at all controlling the power delivery at low RPMs. The sled was VERY predictable and NOT touchy or jumpy under boost. I was afraid that the turbo might kick in rather suddenly and give an unwelcome JOLT of boost all at once. I was quite happy to discover that is not at all how MPI tuned their turbo. The boost rolls in nice and smooth, building in a really predictable manner from 6K to 8K rpm.

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With a little luck I will have the clutch dialed in and take the sled back out next weekend for a 2nd round of testing. Will report back on how she runs at WIDE OPEN THROTTLE then..

turboless terry said:

I can't believe you even took it out with stock clutching. Talk about a fun hater.

Click to expand...

For me its a PROCESS.
One step at a time.

The Turbo Kit was fully installed and it was ready to be TESTED.

Making sure I kept my RPMs in check was NOT hard.
This sled is SUPER PLAYFUL at 8,000rpm even with the clutch in stock mode.

I can ONLY IMAGINE how much MORE FUN it will be NEXT WEEKEND when the clutch is dialed in AND WE HAVE FRESH SNOW from a storm due in Thursday/Friday!!:face-icon-small-hap:face-icon-small-hap:face-icon-small-hap:face-icon-small-hap

Ski-doo#1 said:

Nice. So what is your plan for how you will clutch the sled?

As you said you plan to add a turbo to yours as well, have you thought about comparing kits from another manufacturer? Interesting how Silber has tapped into the Doo ECU I'm thinking that may bring interesting options for fueling as it hasn't been able to be done before for any e-tec.

Just curious and if the MPI works for you in this one I probably would be more apt to sticking with what I know works too.

Click to expand...

I have gone with both BIG boost and SMALL boost.
And right now I much prefer the low-tech small boost route. It just plays out to be sooo much less troublesome.

Honestly, I just do NOT want to screw around with the sled on weekends.
I want to pull the cord and have it RUN STRONG all day long and not worry about any problems from trying to squeeze out every ounce of possible power. Been there, done that, paid the price for being on the bleeding edge of technology.

MPI has proven themselves to be OLD SCHOOL SIMPLE.
And at this stage of my life, that is pretty much exactly what I want.
SIMPLE, IDIOT PROOF, HIGHLY RELIABLE.

As for Clutching.
I plan on giving Mac at MPI a call today and going through that with him on the phone.

I want to dial in my sled for riding at 8,000ft for optimum performance.
That is where I tend to spend most of my weekends in South-East Idaho.

I will share with everyone what MPI tells me.

mountainhorse said:

Will you be ordering your kit for the 2018 with the quiet muffler option?
Would be great to hear the diff.

Keep up the great work with this thread!!
.

Click to expand...

When I look at his page, I do NOT see that as an ordering option, but it is clearly listed in the kit specs? Under the Muffler Options, I only see the MOUNTAIN MUFFLER and a selectable choice.


http://viper.mountainperformance.com/SKiDoo-850-200HP-TurboCharger-Kit-Complete_p_92.html

If he does have a Quiet Muffler option, personally I would probably go for it. At 54, I don't have any real need for the added sound vs. a couple pounds for STEALTH.:face-icon-small-hap



Ski-Doo 200HP TurboCharger Kit
This200HP Kit is a “Turn Key” Turbocharger Kit for the new Ski-Doo 850 Snowmobile.
Factory quality, OEM SkiDoo appearance, 17 year track record of “second to none” quality & performance.

• 200HP at all altitudes - includes EABC (Electronic Altitude Boost Control).
• The Entire Turbocharger Module comes pre-assembled -- Just unbolt the OEM muffler and install the complete turbo/muffler assembly (use all OEM mounting).
• The Intake Side (AirBox, Manifolds, etc) is all Billet aluminum with o-ring seals. No hose clamps. No air boxes or throttle bodies popping off!
• Billet Manifolds houses 2 additional 35# injectors.
• The Entire Turbo Assembly is Stainless Steel. Including the High Flow Stock Sounding Muffler or the Lightweight Mountain Muffler.
• The Quiet Muffler has Stainless Steel Inner Chamber. Ceramic insulation sits between the inner Stainless Chamber and the outer Aluminum Shell.
• Uses Proven MTA / Billet GT2860RS Oil-less Turbocharger. Ceramic Ball Bearing and Billet Aluminum Turbo CHRA - Better cooling and saves weight.
• Oversized fabricated aluminum air-box provides superior throttle response
• Bolt-on installation in hours, not days. No fabrication required, all parts included.
• "Sea-Level Safe" Pump Gas. Automatic Fuel Turning and Automatic Boost Control makes this "Hands-off Safe"
• Higher HP variants & upgrades will be available.

MPI Philosophy & History:

• Before a Product is released to the customer, MPI fully tests and characterizes the product.
• This means that we will NOT offer a product such as our 240HP kit without full durability testing and tuning.
• The turbo side of our 240HP kit is exactly the same as the base 200 kit. BUT the 240HP kit may require simple motor upgrades. We let you know this in advance.
• Performance must be accompanied by uncompromising quality, design, and durability.
• All MPI products must withstand the daily use under whatever trials the enthusiast throws at us day after day without excuses.
• MPI has been manufacturing boost kits since 2003 and 2-stroke snowmobile performance since 1999. All kits have been highly successful.
• MPI is an OE supplier of Turbocharger kits directly to Yamaha Motor Corporation.

Quality & Reliability - The key is a multi-part formula: all pieces must be present (miss any one piece of the combination and the result is an inferior product).

• Top quality parts: Billet / MTA Turbocharger, In-house machined billet parts and In-house fabricated aluminum and stainless steel components.
• Non-compromising design: Drawn from years of experience, education, and use of latest design software tools.
• 17 years’ experience with snowmobiles: This is the 8th generation of our snowmobile boost products and the 4th generation of this particular 2 cylinder design.

200HP Pump Gas Kit all Altitudes:

• Sound Compliant Muffler available.
• Lightweight Muffler Available.
• “Drop-In Turbo Kit” – Installation is as easy as installing an exhaust can and reeds.
• Turn Key Kit requiring no motor modifications.
• No Tuning required on Base Kit
• Plug & Play then Pull & GO
• Consistent HorsePower and Performance across all altitudes. MPI’s Proven EABC (Electronic Altitude Boost Controller) does it all. Up and down hills. High & Low Barometric Changes.
• There are no modifications to the OEM fueling. MPI’s Boost Stand-alone controller drives a special set of Injectors specifically to fuel for the added boost. Simple, Clean and NO TINKERING across all altitudes.
  

109RMSHA said:

Please for the love of mankind quit believing this pump gas turbo story . If you want the engine to last and not overheat and not send det codes at medium elevations (under 8000)please run a little race gas . If you ride at 9000 or 10000 than you may get away with it. I would never trust pump gas in a turbo. I barely trust it in a stock sled . JMO

Click to expand...

Of note.
I had absolutely NO heating issues over the weekend, and the snow was POOR at best, and scratchers were down the entire day. In fact I was surprised at just how COOL the engine was running. Very consistently under 120.

The "KNOCK" indicator did come on ONCE, while in West Yellowstone, while riding on a flat trail at constant velocity (abt 6,000rpm) on the main route out of town. Try though I did, I was NOT able to reproduce it given identical riding conditions. I considered it a spurious warning since I had a good hour of identical riding into and out of West yellowstone trying to get it to happen again.

Gas Mix for the days testing was PUMP GRADE 91 Octane with NO ethanol Mix


[FONT=&quot]Subject: 850 tips from MPI..[/FONT]


1. Operate at or below 8000 rpm.
We have noted damaging detonation occurring at 8500 rpm.
We believe that OEM rev limiting may play a role.
Please just eliminate this potential by targeting operation at or below 8000 rpm (clearly occasionally bumping 8100 is not likely to cause an issue).


2. High quality Pump Premium fuel is required.
Use care with off brand stations. Avoid old fuel (over 2 weeks old).
Race gas is insurance, not required for operation; but we will never say no to race fuel.


3. Do not lean down the MPI GEMS fuel controller.
Do not adjust the GEMS.
We have no indication that our OEM setting are wrong or that any potential drivability issue could be corrected with leaner settings.

4. Should not operate full throttle over 180F water temp.
We cannot tell you how many “bars” this is on the indicator, but you can switch to digital engine temp readout and correlate your bar reading to 180F.
WE HAVE NOT OBSERVED AN OVERHEATING PROBLEM WITH THE VEHICLE.
Just be aware of the 180F limit – we believe the OEM warning does not occur until 212F.

5. If your screen / display show at text message “ENGINE KNOCK / OVER REV”; this is not normal! Performance at MAX boost should be avoided until the problem has been corrected. Items 1 thru 4 above could result in this warning and should be considered when diagnosing a problem.



[FONT=&quot]Regards,[/FONT]
[FONT=&quot]Mac[/FONT]

[FONT=&quot]Mac Randolph[/FONT]
[FONT=&quot]Mountain Performance, Inc.[/FONT]
[FONT=&quot]12379 South 265 West, Unit B[/FONT]
[FONT=&quot]Draper, UT 84020[/FONT]
[FONT=&quot]www.MountainPerformance.com[/FONT]

109RMSHA said:

I know from past experience that it don't take too many nock codes before you start eroding away the cylinder ( Nicasil ) not sure on plaz coated cylinders . I think Id play it safe and add 1 to 2 gallons per tank of race gas. Every time that nock code comes on it's like hitting your piston with a sledgehammer not sure how many times you want to do that?

Click to expand...

I am still doubtful about what I saw.
Engine KNOCK (detonate) when they are under LOAD. Hammer the accelerator and you get knocking.

When just cruising along with no throttle load, knocking is super rare.
I wasn't climbing
I wasn't accelerating
Just running down the trail at 45mph when I saw the indicator for a moment, then it was gone and never came back.

BUT...

I FULLY AGREE on the race gas.

The fuel capacity on the 2017 Summit X is listed at 9.5 gallons

So, if you have a 5 gallon can of VP110 laying around you can mix the following...



1.4 gallons race fuel +91 Octane Pump Gas = 94 Octane

2.4 gallons race fuel + 91 Octane Pump Gas = 96 Octane.

3.3 gallons race fuel + 91 Octane Pump Gas = 98 Octane

4.3 gallons race fuel + 91 Octane Pump Gas = 100 Octane.