BRP reveals future engine and drivetrain refinements at Hay Days
Mountain Sledder | On 14, Sep 2015
Last Saturday, at the much anticipated “Official Start of Winter” Hay Days snowmobile event in Minnesota, BRP revealed some promising refinements to the engine and drivetrain of its MXZx 600RS that we can only hope will find their way into future instalments of the Summit lineup of Ski-Doo mountains sleds, with any luck as soon as 2017.
The upgraded components include:
A new crankshaft and cylinder which are the result of modified engine building processes for tighter tolerances, along with a modified y-pipe and silencer that sheds an impressive 3kg (6.6lb) in weight.
A brand-new “pDrive” primary clutch sporting dual rollers with improved bearings and flyweights that reduces friction and decreases belt operating temps by a claimed 20C (68F), while narrowing the overall dimension by 11mm.
The MXZx RS also sports a new, lighter track which may not ever see the light of day on the production line of the Summit models, but is interesting nonetheless. The same goes for a progressive coupling setup on the rMotion racing suspension that is designed for better holeshots off the starting line.
See the BRP press release below for more details:
Valcourt, QC 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 it’s 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 (3 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.
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./-3 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