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"A 2-stroke twin with 151 stock horsepower? I've got to see this!" That was my reaction when first introduced to the 2-TEC 800R engine in the new Ski-Doo Summit Adrenaline. Cc for cc, a 151 hp, 800cc powerplant would be the strongest stock motor available. We had to check out this advanced 2-stroke technology for ourselves, so we had Rich Daly at Dynoport strap one on his dyno and put it through the paces.
The hypeThere has been plenty of hype around this sled and its new liquid engine, and for good reason. The 151-inch Summit with this 800R engine only weighs 483 lbs. (489 lbs. at our weigh-in, p. 12). That is astounding for a stock vehicle over 10 feet long, and the best stock power-to-weight ratio (dry) in its class of mountain machines. The long-term jury is still out on whether or not it will perform better than its competition in the mountains, but on paper it is certainly a head above the rest in the engine bay.
This is a cool running engine with water-cooled crank that we were told sees its best power between 70 and 80 degrees running temperature. Yep, you heard right, this is not a hot running machine - from a temp standpoint - and there is no thermostat on this engine. There's some Rotax engine mastery here!
This engine idles at 6,200 rpm and the 800R comes with the new 3-D
R.A.V.E. exhaust valves with 42% larger R.A.V.E. bellows. It also has a throttle position sensor, knock sensor, crank position sensor and ambient temperature sensor.
The pullBefore we get to the data, we should note, that there is a specific sensitive sensor built into the electronics on most Ski-Doo engines that retards the timing and does not allow them to run at their highest potential for approximately the first 8 hours of use. Exactly how many miles that is, obviously varies, but most owners usually put on 200-300 miles before they start to see the performance of the new Doos really take shape.
We ran our 800R a little warm, from 80-90 degrees running temp, and jetted down slightly. On the official run, our Summit 800R engine snarled up to 155.7 hp at 8,100 rpm. That's more horses than any current 800 from Cat and more than Cat's old ZR 900. It's also more than the recent Polaris Fusion 900 and it edges Yamaha's biggest stock 4-strokes. We dynoed the 800R to be 15 hp more than the standard Ski-Doo 800 Powertech engine on the same day with the same dynomometer.
We also talked to some of the mountain folk who have had this engine on their dynos at higher elevations than our basically sea level start. They report solid 151 hp pulls too.
Torque from the 800R engine showed best at 8,100 rpm too. The 101 foot-pounds is about 8 more than the standard 800 engine delivered. The 800R simply out-does its 800 and 1000 4-stroke competition in the torque department too.
Comparing the 800R with the next highest 2-stroke cc level is what we would have to do to really keep the competition close. The torquey 2006 Arctic Cat ZR 900 pulled 110 ft.-lbs. at 7,200 rpm, and the Polaris Fusion netted 103.2 ft.-lbs. at 7,200 rpm. To be fair, the 800R is slightly less torquey than these bigger 900s, but meets or exceeds them in horsepower.
Gotta have it While we are excited for the guys in the mountains to get to spend the winter playing on this lightweight throttle thoroughbred, us Midwestern riders are saying we gotta have this engine in a trail machine!
How about this engine in the new X-RS trail package? It would humble any terrain in the crossover Renegade set-up too!
We definitely expect to see this engine in other applications next season. For this year, only the Western riders - and probably a few lucky gear-heads who will drop one of these engines into a short-track model - get to enjoy it.
Ski-Doo Summit 800RRPM, Horsepower, Torque (ft-lbs.)
6,500 100.2 80.9
6,600 101.9 81.1
6,700 107.2 84.1
6,800 111.1 85.8
6,900 114.1 86.9
7,000 118.2 88.7
7,100 121.9 90.1
7,200 125.7 91.7
7,300 128.8 92.7
7,400 133.0 94.4
7,500 136.4 95.5
7,600 140.1 96.8
7,700 144.0 98.2
7,800 146.4 98.6
7,900 150.3 99.9
8,000 153.1 100.5
8,100 155.7 101.0
8,200 155.3 99.5