Ski-Doo took the wraps off of its 2016 MX Zx 600RS race sled this past weekend at the Haydays Grass Drags, and it has many notable changes. Most changes are directly tied to Ski-Doo’s efforts to let its X Team racers get a better holeshot at the start of snowmobile races — including changes in the engine, a new primary clutch, upgrades to the track and the loss of major weight in the exhaust system.
Also, the brand is promising a new coupling system for the rear suspension, though details on that were not released at the Haydays event. Here’s the press release from Ski-Doo, along with photos taken by the incomparable Andy Swanson.
New SKi-doo MXZx 600RS gets engine updates, New Clutch, trims weight
Valcourt, Québec, September 12, 2015 – BRP introduces the 2016 Ski-Doo MXZx 600RS racing snowmobile designed specifically to attack North American snocross tracks. The sled will feature a radically updated engine, new clutch, and suspension changes that result in better acceleration, traction and rider control.
The MXZx 600RS already has a proven track record of durability, great handling and low maintenance costs for its racers. For 2016, the Race Engineering team in Valcourt concentrated on engine, clutch, suspension and track development to deliver better starts, better drive from corner to corner and more power throughout a race.
The Rotax engine features a new cylinder design with a tight tolerance manufacturing process to maximize power and consistency. In addition, there’s a new crankshaft, drive clutch and stator that reduce inertia more than three times compared to last season’s light weight crank program. The powerpack also features a new Y-pipe shape, and tuned pipe to match the cylinder changes, plus a lightweight muffler that shaves six pounds (2.72 kg) off the sled. These changes together deliver fast revving, consistent and robust power from engagement all the way to the 8500 RPM redline.
To make the most of the additional power, the Valcourt Race Shop matched the engine with a completely new high performance pDrive primary clutch. This new pDrive is designed to reduce friction, reduce weight, tighten tolerances, allow for more consistent RPM delivery, require less maintenance and last longer. To accomplish this, the specialty racing pDrive clutch features unique elements like fast and friction-free dual rollers to transfer torque in place of traditional sliding buttons, the renowned BRP-exclusive adjustable clickers – only this time applied to flyweights, needle bearings in oversize rollers and a compact open design that’s also 11mm narrower. The new clutch and new clutch cover combine to reduce belt operating temperature by 68° F (20° C).
Another driveline component seeing change is the track. A new lightweight track that shaves an additional 2 pounds (.9 kg) of rotating weight takes the basic design from last year and reshapes the lugs down low while adding strength with towers at the ends and in the middle of each lug for both better holeshots and more durability. Late season testing shows the new track gaining a consistent one half to one full sled length advantage over last year – without considering the engine and clutch changes.
In the quest to gain every advantage possible, there will also be a new patent pending progressive coupling device that can be added to the renowned Racing rMotion suspension that’s used on the MXZx 600RS. This device aids in weight transfer and chassis dynamics to deliver the explosive holeshots every racer wants.
Recap of changes
New Cylinder: New design and manufacturing process for more power and consistent output from each part
New Crankshaft: Improved lightweight design for fast spool up
New Stator: Lightweight design for faster revving and reduced inertia
New Y Pipe: Matches new cylinder
New Tuned pipe; Matches new cylinder
New Muffler: Lightweight (-6 lbs./-2.72 kg)
New Racing pDrive Clutch: Low inertia, roller and flyweight design
New Track: Two pounds (.9 kg) lighter, stiffer lugs/paddles, more durable
Clutch Cover: Reduces belt operating temperature by 68° F (-20° C)
Progressive coupling: For explosive holeshots
New Seat shape: Lighter and more room for driver