With the arrival of the 4th generation REV chassis, Ski-Doo has announced a new evolution of the concept of mass centralization. Both on the trails and in the powder, the Valcourt manufacturer promises a new riding and handling experience. Combined with an all-new 2nd generation E-TEC engine, it’s an entirely new vehicle that is presented to us with the test of the 2017 Ski-Doo Summit 850 E-TEC 154.
Although I had the privilege of testing it at the 2017 Snowshoot last spring, the team at TY Moteur, a well-known BRP dealer in the greater Quebec City area, gave me a nice gift for the holiday season by offering me the opportunity to test this new Summit for a few days. Having received good amounts of snow on the Valin Mountains, we managed to find a suitable playground to relive the spring experience but this time in the conditions of the Quebec backcountry. Not having the vast, expansive landscapes seen in the Canadian Rockies where the trees are more distant, we were faced with very dense forests with little room to maneuver between obstacles. So I wanted to see how the Summit would perform in these difficult conditions for the rider, as well as the snowmobile.
Right off the bat, I recognized the distinctive response of the new 850 E-TEC engine. When I tested it last spring, we were at nearly 7,000 feet and still impressed with this aspect of the engine. But at 2,000 feet, it’s a real “wow” in my headset every time I step on the throttle. Combined with the 15x154x2.5-inch Powdermax FlexEdge track, the response of the new Rotax is explosive at all rpm and is a major asset for this type of vehicle. Several technological improvements explain this performance, including the addition of new booster injectors, the new E-TEC electronic system processing twice as much information per second, the reduction of inertia induced by the engine’s internal parts as well as the reduction in weight of the new P-Drive pulley. There is a slight vibration at certain engine speeds, but this is often the price to pay for a more responsive engine.
The other striking feature compared to the XM chassis is how fast the Summit climbs on the snow at the touch of the throttle. There’s a very light front-end feel, as the front-to-back balance of the snowmobile is truly optimal. Engineers reworked the centralization of the drivetrain towards the center of the vehicle. For example, they placed the snowmobile’s battery at the back of the vehicle’s seat, a 15-20 pound shift from the front to the center. This balance reaches another level when you start maneuvering from left to right in the powder. The REV G4 chassis reacts as soon as the rider presses a step and in the same way on the left and right. This probably has something to do with the left-right centralization of the drivetrain, which is almost 50-50. Naturally, the t-Motion suspension is well suited to the new chassis, being one of the last “remnants” of the old Summit generation.
After several hours of riding in 3 to 4 feet of powder, I realize that my impression of the spring was correct. The hyper handling of the new Summit 850 E-TEC 154 and the power of the new Rotax are major assets for the tight maneuvers we do in Quebec. Moreover, you become very adept with this snowmobile in just a few minutes, which shows that the people at Ski-Doo have succeeded in their gamble.
