The New rCTRL Rear Suspension

The design of the rCTRL (center-to-rear-linked) rear suspension focused on enhancing rollability and increasing damping capacity, enabling the Lynx Rave RS snowmobile to achieve faster laps on snocross tracks. Durability has been improved, and maintenance has been simplified.

The revolutionary rCTRL rear suspension is based on a unique coupling system. In this mechanism, the center arm borrows damping force from the rear arm through the shock absorber to the center arm area. This unique solution provides the center arm with increased damping power without an excessively stiff center shock.

The center arm plays a pivotal role in modern snowcross racing, as the rider’s and sled’s mass is centralized in a smaller area on the middle of the sled, subjecting the center arm to substantial forces. The rear arm of the rCTRL suspension operates independently at all times, with force applied solely to the rear arm. For instance, when the sled lands with rear weight after a jump, the rear arm smoothly follows the landing, without slamming down the front end of the sled.

The carrying capacity of the rear arm is guaranteed by using a long shock absorber with a total dimension of 590 mm and a stroke length of 175 mm. The long stroke allows the suspension open more, giving more damping force on the landing of jumps. In addition to high damping capacity and carrying capacity, the advantages of a long damper are also easy adjustability.

Thanks to the new geometry of the rCTRL rear suspension, the Rave RS rolls significantly better than its predecessor, especially when riding on bumps. Due to the small variation in the track tension, the pre-adjustment of the track tension can be left looser than before without the track ratcheting.

The slide rails of the rear suspension are machined to their shape from aluminum profile. The center arm is attached to the frame with a fork, which means that to remove the rear suspension, it is enough to simply loosen the bolts of the rear arm and pull the rear suspension out. Parts have been reduced in the name of maintainability and weight saving: the number of parts is reduced by a third which means a weight saving of 5 kg compared to its predecessor. The rCTRL rear suspension is now more service-friendly and faster to maintain, much to the relief of racing team mechanics.

The limiter strap is located outside the suspension, and adjusting the strap does not require opening the strap loop. The bolts of rear suspension are standardized and fewer different tools are needed for maintenance than before. The bolts are placed in such a way that they are easily accessible from the outside of the suspension. The attachment of the rear arm to the slide rails is done by slide sleeve.

The LFS Racing front suspension of the Rave RS racing sled uses new, taller spindles. The change goes hand in hand with the new rCTRL rear suspension, bringing 27 mm more ground clearance under the lower A-arm. As part of the reform of the sled’s suspension, the swaybar has been removed, which contributes to the sled’s weight savings.

Renewed Radien-RS Chassis

The Rave RS 600RS E-TEC has also experienced significant reforms in terms of the structure of the chassis. Four-point engine mounting, lower located running boards and further strengthened structure mean increased performance, better handling and enhanced reliability.

The fierce powerhouse of snowcross tracks, the Rotax 600RS E-TEC engine, is now mounted to the chassis via four attachment points. The alignment of the powertrain is now more constant due to the stiffer engine mounting, which improves the efficiency of the transmission and thus increases the performance even more.

The S-module of the front frame has been strengthened with a new, straight crossbar and new reinforcements. The running boards are 30 mm lower than before, which brings the center of gravity lower, making cornering easier and helping the rider to get support from the sled when jumping. At the same time, the rider’s foot holders have been brought back 5 cm.
The disc brake cover features additional perforation to improve the cooling of the brake.

The new calibration of the engine optimizes the performance in line with other innovations of the Rave RS factory racer: more power, more speed on the track. The ignition coil and the Rave motor have been repositioned lower on the chassis than before, which lowers the center of gravity and keeps the important components better protected.

Thanks to the new bearings in the chain case, removing the drive shaft is much faster and easier than before. In the future, the track can be replaced without disassembling the chain case, which makes the maintenance staff’s race weekends significantly easier.

Thanks to the more evenly shaped chassis and larger ground clearance, the bottom of the sled hits the snow less often than before, improving the progress of the sled on soft tracks. The rCTRL rear suspension is attached to the rear chassis with a fork-type lug, which distributes the force more evenly to the bearings.

The redesigned RS seat has been brought 30 mm lower along with the running boards, which, together with the chassis changes, lowers the center of gravity.

Lynx Rave RS 600RS is built on Radien-RS chassis and its uniqueness is the short rear chassis and the flexible rear part made of polyethylene. The flexible rear part, unlike the aluminum tunnel, is easy, quick and inexpensive to change in case of damage.

Aiming to Continue The Championship Streak

Lynx Rave RS has been number one on European snowcross tracks for years. In the spring 2023, the Finnish Aki Pihlaja achieved the coveted world championship title with the Rave RS in Kirkenes, Norway, and is eager to renew the title in the 2024 season.

Lynx was by far the most successful racing sled also in the Scandinavian national series: Rave RS riders achieved a total of 12 championships in the 2023 season, complemented by more than 20 podium places.

The completely renewed Lynx Rave RS 600RS E-TEC race sled has gone through a tough test program by front row drivers. The project and test group has included riders who have achieved a total of nearly one hundred prestigious race medals.

2024 RAVE RS 600RS E-TEC HIGHLIGHTS:

● Renewed Radien-RS chassis
● Re-calibrated Rotax 600RS E-TEC engine
● New rCTRL rear suspension
● Renewed LFS Racing front suspension
● KYB PRO RS 46 HLCR Kashima shock absorbers
● 381 x 3487 x 44 mm track
● 1092 mm ski stance
● Racing pDrive -primary clutch ja Team TTS-04 driven clutch
● 4-piston Brembo Racing brake with improved cooling
● Pilot Racing skis
● Renewed RS seat
● New coloration

Four straight seasons of championship form, led by Elias Ishoel’s, Jordan Lebel’s and Malene Cottew’s ISOC crowns last season, hasn’t affected the team developing the MXZx 600RS as they continue to chase their own records and push for even more performance.

The REV Gen4 platform continues to prove its flexibility and prowess for riders of all abilities, and that focus – making it fast, adaptable and reliable for all – remains the same formula for this season.

Most noticeable will be the yellow color update that maintains the Ski-Doo DNA, while other chassis and powertrain refinements ensure the winning ways continue. Changes focus mainly on better traction, faster corner speeds and a smoother ride to deliver better holeshots, faster overall lap times and less rider fatigue – but no stone is left unturned as engine and clutching improvements are constantly updated every year too.

The chassis changes start up front in the RAS RS suspension with new shocks that are shorter in overall length while maintaining the same travel to help lower the center of gravity, and spring rate has been increased to reduce roll, both changes support better cornering. The front suspension continues to feature a long spindle design that allows high cornering speeds and a unique power steering system exclusive to the MXZx RS race sled that provides ultra-precise handling with less effort.

The RAS RS front suspension updates are complemented by the redesigned rMotion RS rear suspension where the front arm is shortened and the rail mount is moved up for a flatter profile that results in less ski lift and more forward traction when on the throttle out of corners.

The center shock also grows in length to position the front of the rail in more constant contact with the snow surface for better traction everywhere. The increased length also delivers more shock and suspension travel at the front and also provides a motion ratio closer to 1:1 (more linear) for better shock control, bump compliance and rider comfort.

The rMotion RS’s rear arm mounting points are moved back, the shock travel is increased, and its motion ratio also gets closer to 1:1 – these changes support a lower center of gravity, better traction and less ski lift out of turns to drive the sled forward faster.

The coupling system is revised for a wider window of adjustment and there’s a new easily activated and more effective holeshot device.

The MXZ RS retains 46 mm KYB Pro Series shocks that have Integral Base Valves with the ability to adjust not only High and Low Speed Compression but also High Speed rebound and calibration has been updated to match the suspension geometry changes based on feedback from racers testing prototypes last winter.

The MXZx 600RS E-TEC uses the REV Gen4 platform with its open cockpit design and centrally balanced engine for superior rider ergonomics and handling in rough conditions. The REV Gen4 layout delivers agility and responsiveness while the Ergo Step side panels and beveled tunnel allow racers the room they need to attack the course – without interference from the chassis.

The Rotax 600RS E-TEC engine features E-TEC direct injection that consistently delivers quick response and perfect calibration no matter the altitude or weather conditions, allowing racers and their crew to have less to worry about.

Features include booster injectors first deployed on the Rotax 850 E-TEC, a short intake tract with double reeds and digital eRAVE. Engine calibration refinement for 2023 focused on better low RPM and low vehicle speed responsiveness to provide more power out of deep holes or under heavy load conditions – letting racers accelerate faster.

REV Gen4 Platform:

• Taper/tilt tunnel design
• Short heat exchanger with internal loop
• 137” Track
• Lightweight Lexan Hood
• Quiet, high flow Airbox Design
• LED Lightweight Headlights
• Reinforced E and S modules
• MX inspired seat and hi-traction cover
• Racing foot box
• 5-gallon fuel tank
• NEW Lower center of gravity
• High Air Flow Left Vent

RAS RS Front Suspension

• NEW shorter Kashima coated 46mm KYB Pro Series shocks (High Speed /Low Speed compression and High Speed / Low Speed Rebound adjustments)
• Integral Base Valve Adjuster
• NEW shock springs
• Rack steering with power assist
• Long Spindle design (Stronger + better speed cornering)
• New Color
• Lightweight Pilot R2 Ski – Reinforced rMotion RS Rear Suspension
• NEW Race proven rail design, higher front arm mount, new color
• 137” length
• NEW shorter front arm
• NEW longer front shock
• NEW rear arm mounted back approximately 1”
• Kashima coated 46mm KYB Pro Series piggyback center shock w/ High Speed / Low

Speed compression and High Speed Rebound adjustment

• Kashima coated 46mm KYB Pro Series piggyback rear shock w/ High Speed / Low Speed compression and High Speed / Low Speed rebound adjustment
• Integral Base Valve Adjuster
• Revised geometry
• NEW Coupling configuration NEW Holeshot Device

Rotax 600RS E-TEC Engine (599.4 cc)

• E-TEC direct injection
• Monoblock cylinder design with Plasma coating- delivering more horsepower
• NEW engine calibration
• Intake booster injectors (850 E-TEC-inspired)
• Shorter intake length (850 E-TEC-inspired)
• Double reed valves (850 E-TEC-inspired)
• eRAVE (850 E-TEC-inspired)
• Lightweight exhaust system (Stainless steel tuned pipe)
• Racing Throttle Block – Ready for 50% throttle applications
• Reinforced engine mounts
• Hot Start Button

Drivetrain

• Large brake backing plate
• Brembo Brake System – large diameter rotor, easy maintenance caliper
• pDrive primary clutch
• TEAM TSS-04 secondary clutch
• Slip gear – Better durability, less maintenance
• Lightweight belt guard – better air flow

A LITTLE HISTORY

Along with being known as the original outboard engine, Evinrude has had a storied 100-plus year past. In the late 1990’s the parent company of Evinrude (and Johnson), Outboard Marine Corporation (OMC), was thrown into disarray by corporate raiders.

This event led to BRP’s acquisition of the Evinrude and Johnson brands including a 2-stroke Direct Injection (DI) system known as Ficht Ram Injection. After BRP’s acquisition Ficht was re-branded and re-engineered becoming E-TEC Direct Injection.

The system debuted on BRP’s Ski-Doo snowmobiles in MY 2008 and the rest is history. Today E-TEC is still the only Direct Injection system in the sno-mo-biz.

It’s interesting to note, when OMC Corporation went into receivership and BRP acquired Evinrude, Johnson and Ficht, it did so for a relatively attractive sum in the corporate world.

EVINRUDE AND THE MARINE BIZ

The marine industry has almost, without exception, adopted a sales model called “vertical integration”. Vertical Integration requires outboard OEMs to acquire boat manufacturing companies their engines can be exclusively installed on.

In other words, many (if not most) of today’s boat OEM brands are actually owned by Mercury and Yamaha. While this has gone on for the past 15 years (or more) BRP took a different path and marketed its engines to the “re-power” market.

Only recently did BRP jump into the boat biz and begin vertical integration in a sizeable way.

OUR 2 STROKE SENSIBILITIES

Honestly, we’ve felt a sense of pride in the success of the Evinrude brand knowing it is the only outboard engine using 2-stroke power exclusively.

The E-TEC paradigm in the outboard world stood alone for almost two decades. E-TEC’s performance, lightness and EPA cleanliness, not to mention its exceptional fuel efficiency, set Evinrude apart from the 4-stroke hoard.

A PAUSE OR THE END?

Reading what BRP had to say about the cessation of Evinrude production, we perceive the company is not likely to re-introduce the brand. However, BRP has stated it won’t sell the brand either. In fact, in any corporate communications we’ve seen since this announcement Evinrude is still listed as a BRP brand.

E-TEC

BRP and, in particular, the Ski-Doo Division, have made it clear the cessation of Evinrude E-TEC production has no effect on E-TEC 2-stroke development as it relates to snowmobiles.

In fact the company has made it clear E-TEC snowmobile power will continue to be developed and used in Ski-Doo snowmobiles indefinitely.

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I remember my first experience with a low-emissions 2-stroke the first time I rode it. I checked the oil tank and started to panic. “Surely, I’m going to ruin this engine. Something must be wrong with the oil pump – or an oil line must be blocked – because it just isn’t using enough oil at all.”

The fact is 2-stroke oil is a pretty amazing substance, sticks like glue to wear surfaces and mixes with gasoline very uniformly and rapidly.

In pre-mix situations you can go as high as 100 to one gas-to-oil ratio with some oils and not damage your engine. Seems almost ridiculous!

With Semi-Direct and Direct Injection engines there’s very little gasoline introduced into the crankcase – in some cases, none. As a matter of fact, an E-TEC engine’s crankcase is pretty much sealed-off from the engine’s combustion chambers when it’s running and there’s only fresh, clean air allowed by the throttle bodies into the bottom end which is immediately transferred via transfer ports to the top of the engine.

This is one of the reasons the engine uses so little oil: When there’s no gasoline washing down or diluting the oil going to the crankshaft and rod bearings every stroke, the lube stays on those bearings way longer.

With an E-TEC engine or a Polaris Cleanfire SDI, the oil is “pin-point” injected in minute proportions directly onto those bearing surfaces. Piston rings and wrist pin lube is also delivered by the oil pump.

The point is, very little oil is needed on those engine parts because gas isn’t mixing with the oil and washing it off the bearings and up the transfers. As a result you don’t use as much oil as the old days of carburetors and mechanical oil pumps.

Less oil consumption makes a great case for the newest electronic oil pump technology that links up with the sled’s ECU to determine how much oil is demanded by the engine at whatever particular RPM it’s running.

These new “smart” oil pumps are a big part of the reason the newest-gen 2-strokes can run so oil lean.

It’s impressive to read the comments you’ve added to the articles and pretty awesome how much of an understanding snowmobilers have of the function of the different 2-stroke systems out there: E-TEC, DSI and SDI.

Let me deal with a few of those comments:

1. Yes, it’s true, the new 600R Rotax is the most recent engine offered in the 2-stroke class, superseding the original E-TEC introduced in the 2008 model year.

The basic principle of how E-TEC works is the same on the original Series III 600 and the new 600R.

Due to its centered mounting position in the new G-4 chassis the new engine had to be much narrower. This was accomplished through the use of a flat stator.

There’s more, subtle refined tech to allow the 600R to run a safe 125-horsepower – however, E-TEC is E-TEC and its snowmobile adaptation has been around for over a decade.

In the article our target was to try to describe in the most general terms how Ski-Doo’s Direct Injection system works. Even though the OEMs are constantly updating and upgrading technology the 600R E-TEC uses a similar basic operating principle.

2. We referenced liquid cooled cases and it’s true, neither the 600 or 600R uses this crankcase cooling setup, instead both versions use the super-grease system we referred to in the article.

This grease is permanently sealed into the bottom end bearings. That system has proven reliable on the original series III 600 but 800 series III E-TECs were a riskier proposition.

This has to do with the kind of sustained high RPM 150 plus HP engines are subjected to. Because of the increased power output of the old 800 versus the original 600, larger bearings were required which require more lubrication and cooling.

Rotax uses liquid cooled cases on the new 850 – along with pinpoint oiling. All E-TEC engines (and SDI engines) use electronic detonation sensors. They are mandatory equipment on E-TEC engines which run exceptionally lean.

3. This one refers to the fact that in a conventional 2-stroke the piston is compressing fuel every stroke and not every other stroke as mentioned. To clarify, every time the piston moves to top dead center – that is once every rotation of the crankshaft, the spark plug fires.

Compression occurs every time the piston moves to top-dead-center. Remember, as the piston rises, fuel and air are being introduced into the crankcase with carbureted and throttle body injected 2-strokes. To be clear, a fresh mixture is always moving into the crankcases as the piston rises.

This fuel is then pushed up the transfers as the piston falls. When the rising piston closes off the exhaust port the fresh charge which entered the cylinder from the transfers has pushed out the burned charge into the exhaust pipe.

Once the exhaust port is closed the fresh charge is compressed and then lit-off by the spark plug at top dead center. The piston then travels downward and a fresh charge moves up the transfers as the piston falls starting the whole remarkable process over again.

The reason the EPA is tough on 2-strokes is due to the uncontrolled movement of unburned fuel and air out the exhaust port before the rising piston closes the port off.

This unburned mixture is still a consideration on SDI engines although SDI “in-port” injectors dramatically improve emissions.

E-TEC engines – which do not inject fuel into the combustion chamber until the rising piston closes the exhaust port, are the cleanest 2-stroke engines in the business.

Consider this: The E-TEC injector has only 15 degrees of crank rotation after the exhaust port is closed, to inject a fresh charge of fuel.

It’s worth noting tuned expansion chambers (pipes) and exhaust port modifiers both have a profound effect on 2 stroke snowmobile engine efficiency.

4. Yep, the slot-injected Cat 600 has been around longer than I thought. I gave it about five years but it’s actually about seven. My apologies.

Here’s how E-TEC 2 stroke Direct Injection works:

FIRST, THE CONCEPT

Direct injection (DI) differs from all other 2 stroke induction systems in that absolutely no fuel enters the engine’s crankcase. The throttle bodies allow only air to enter the engine’s bottom end.

While air is pumped upwards to the combustion chamber via conventional transfer ports oil is pinpoint injected onto the rod bearings and piston skirt. This oil slowly migrates up the transfer ports and is ultimately burned.

Since so little oil is involved as a result of keeping fuel out of the scavenging process (which would normally wash down the bearings) there is almost zero smoke and odour associated with the system. Because fuel is injected so late in the 360 degrees of crankshaft rotation, virtually no unburned fuel escapes into the exhaust system.

UP TOP

E-TEC’s hallmark feature is its electronic voice coil injectors externally mounted on the cylinder head over the combustion chamber.

Voice coils use a similar process as stereo speaker magnets to produce pulses of fuel to the cylinders. The injectors pulses take fuel from relatively low pressure to over 2000 psi in less than the blink of an eye.

The voice coils literally hammer fuel into the cylinder with each pulse. The sled’s ECU (computer) adjusts the stroke of the voice coil injector pin to meet the engines demands determined by the ECU.

The “magic” of the E-TEC system is this. To ensure no unburned fuel escapes out the exhaust port the voice coil injectors are able to introduce fuel into the combustion chamber after the exhaust port is closed.

With only 15 degrees of crankshaft rotation left before the spark plug lights off the compressed fuel and air virtually no fuel escapes out the exhaust port.

Other than a higher cost to manufacture compared to other 2 stroke SDI injection systems there’s no downside to E-TEC. BRP is able to deliver the cleanest running, highest efficiency, low emission 2 stroke engines in the biz as a result of E-TEC’s sophistication.

One more E-TEC benefit is easy starting. Due to its high pressure injectors and high voltage electronics, an E-TEC engine only requires a 120 degree rotation of the crankshaft to start it. That’s why the revolutionary “SHOT” electric start system is possible. E-TEC atomizes fuel so efficiently the engine lights-off with only a tiny bit of crankshaft movement.

The new 600R engine with E-TEC sets the bar very high for snowmobile power and performance as well as efficiency and cleanliness.

Ski-Doo hasn’t missed a beat since the original 2003 REV hit the ground and stole number one sales and market share laurels from Polaris. Up to that time Polaris had held nearly a two-decade-long stranglehold on snowmobile sales market share.

In the late 1990’s, Laurent Beaudoin, then Top Gun of Bombardier (which included the aviation and rapid transit businesses at that time) and son-in-law to the iconic J. Armand Bombardier, had made it clear he wanted Number-One status back in the Ski-Doo camp.

As the story goes, Bombardier Recreational Products CEO and powersports visionary, Jose Boisjoli knew he needed two things to happen to satisfy Laurent Beaudoin’s call to arms and to elevate Ski-Doo back to leader status – something the company had lost in the early 1980s.

First, he knew he needed a game-changing snowmobile. The REV platform was that game changer, so much so that over the next few model years every OEM moved to imitate the REV’s now industry-standard “rider forward” ergonomics.

The second thing Boisjoli needed was for the current market leader to fall asleep. In what will go down in sno-mo-history as a strange aligning of the stars, that exact thing happened.

For reason’s too complex to delve into here, Polaris didn’t have the “next big thing” in its repertoire and was slow to respond to the arrival of the REV. Back in 2003, Boisjoli got his “two things” and, as they say, the rest is history.

BACK TO TODAY

In case you hadn’t noticed, Polaris has kept its head down while on a mission to increase market share. The company’s passion for these laurels appears to know no bounds.

Polaris has innovated engine designs, engine technology and has re-invented snowmobile suspension twice in the last ten years. The company has identified competitive areas it can “own” as Polaris distinctives, and bolstered those strongholds on an annual basis.

Specifically, those areas are:

1. Deep-snow performance leadership
2. On-trail handling leadership and
3. The lightest weight on virtually every sled it produces in every segment.

To see how far Polaris has come this decade is doubly remarkable, considering it does not have a 4-stroke snowmobile. We believe this may be about to change soon. Consider this: Ski-Doo sells more 4-strokes than Arctic Cat and Yamaha combined. That’s a lot of snowmobiles!

Despite this, Polaris has actually been gaining market share. Most importantly, for now it has grown its 2-stroke business rapidly.

The recent launch of the 850 Liberty engine has been nothing short of impressive. The new Indy XC platform with Pro CC suspension has brought back considerable numbers of former Polaris faithful who had drifted to other brands.

DOUBLE DIP

In our humble opinion, if Polaris brings a 4-stroke engine to the party, the company will be fully weaponized and ready to do nose-to-nose battle with Ski-Doo in every segment right down to the last sales contract.

My headline question was “Who is the competition?” I think it’s safe to say Polaris is Ski-Doo’s competition and even though you’ll never hear those two OEMs complain about gaining market share from Arctic Cat or Yamaha, it is clearly double-dipping when one of them gains it from the other!

At this point Ski-Doo knows it cannot take its enviable leadership position for granted. A wise marketing Guru once said to me: “Number One is not a destination, it is a journey!”

The GSX was a tamed-down version of the MX-Z with less sophisticated shocks and, in 2009, offered choices of both 600 E-TEC power and a 4-TEC 1170cc 4-stroke.

We like the GSX as a used sled because of the type of owner who bought one. Since this was not regarded as an all-out performance model, chances are these sleds may have led an easier life than some MX-Zs and Renegades.

The truth is, however, except for shocks and aesthetics, the GSX is an MX-Z in nearly every imaginable way. The 600 was built on the super-light XP platform and the 4-TEC used a modified, slightly wider XR chassis to accommodate its big-inch 4-stroke.

This brings up another good point: That 1170cc 4-stroke was the largest engine put in a snowmobile (still is) and that probably means there might have been less stress than on a smaller one. This 4-stroke has proven to be durable and is a versatile, fun sled to own – especially if you’re a trail rider.

Some considerations:

1. The 4-TECs had annoying throttle lag that takes some getting used to. Once you’re onto it, though, it’s not much of a concern.

2. Beyond 10,000 miles the 600 E-TEC may need a bottom end refreshing because of the sealed, grease-lubed bearings in the crankcase. Pricey, but many 600s go well beyond 10,000 miles without it.

We give the 4-stroke GSX LTD a 4.5 out of 5 and the E-TEC a 4.