Ski-Doo’s First Turbocharged X-RS
For the first time ever, Ski-Doo buyers will have a turbocharged 4-stroke option in the Renegade X-RS series – the 2019 Renegade X-RS 900 ACE Turbo. The advanced Rotax 900 ACE Turbo brings an aggressive 150 horsepower to one of the most capable platforms ever offered, easily combining to deliver one of the best handling and best riding four-stroke sleds the industry has ever seen. This newest X-RS powerplant brings a hard-hitting turbocharged 3-cylinder capable of arm-stretching acceleration, and in the X-RS package it offers supreme shock capabilities for riders who demand premium 4-stroke performance in every way.
Powerful and sophisticated, the 150-horsepower Rotax 900 ACE Turbo delivers that hard-pulling four-stroke torque and acceleration at the punch of the throttle. With a Rotax-built turbocharger specifically designed for a purpose-built version of the 900 ACE engine, riders get the technology they love with the reliable, powerful performance they demand in one advanced engine package. Like the base 900 ACE, this turbocharged engine also includes drive-by-wire intelligent Throttle Control (iTC) with three driving modes (Sport, Standard, ECO) and finger throttle capability.
1,500 Mile Test Report
By the end of March, SnowTech test riders had logged 1,500 miles on the all-new 2019 Ski-Doo Renegade X-RS 900 ACE Turbo. Our first encounter with this new beast was in late January up in Quebec, followed by a photo shoot and ride evaluation in late February, and then we took delivery of our very own prototype sled (#007) that we racked up another 1,386 miles on before we had to send it on its way. With these three opportunities over a three month period we were able to sort out the fact from the fiction and came to some pretty startling conclusions of what this sled actually is, and isn’t.
For starters, this sled is not really comparable to a Yamaha Sidewinder. We say this because it is the most logical machine to compare it to, and if you’re expecting the performance of a 200 HP Sidewinder, the 900 ACE Turbo is not quite in that league. This is a 150 HP sled, one that has impeccable handling and the very best rear suspension you can get, so the ride and handling of the Renegade X-RS is also not in the same league as the Sidewinder. But back to the power, if one is used to the instant throttle response of the Sidewinder and the wicked acceleration that 200 HP delivers you will find the 900 Turbo to be somewhat tame in comparison. Know that going into this, as Ski-Doo did not target the Sidewinder.
There are a number of current Ski-Doo 1200 4-TEC owners complaining that Ski-Doo didn’t turbo charge their beloved 1200, as that package surely would have made more power, but again, that was not the target. Ski-Doo believes their 150 HP machine will sell far more units over the next five years than what Yamaha would ever see from their 200 HP Sidewinder in that period of time. Marketing research and data appears to back up this claim, as “hero” sleds like the Sidewinder typically sell very well the first year but then see progressively fewer units sold each year thereafter, as the market typically only supports so many of the top power machines. This has been the case throughout the history of the sport. Ski-Doo believes they will be able to sustain far more unit sales over a far longer period of time with a 150 HP Turbo, aimed at the heart of the market rather than a smaller slice up top. The 121-160 HP segment is far larger in terms of unit sales, and this is where Ski-Doo wanted to capture more than their current 30% share of.
Ski-Doo did deliver +20 HP over their 1200 4-TEC with the 900 Turbo, and did so at the same vehicle weight. This new engine will produce a full 150 HP all the way up to 8,000 feet of elevation, something the 1200 of course wasn’t able to do. The new Gen 4 Wide platform (new plastic on the Gen 4 chassis) is a full 3/4” narrower than the REV-XS that housed the 1200, so the resulting sled feels narrower than the 1200 XS models as well.
Why does the snow version of the 900 Turbo only produce 150 HP when the side by side dirt version produces over 170 HP? We’re told it is all due to the tighter packaging of the snowmobile, with the engine and turbo and intercooler all crammed into the confines of the underhood area on a snowmobile. Heat management becomes a huge issue, especially when we consider all of the steering and suspension components also in the same underhood area as the engine, intercooler, intake and exhaust. Translation, the tighter packaging limited the ability to cool enough air under the hood, so this engine was specifically customized for the snow application and is not the exact same engine as the dirt version. Very similar, but different. It spins at 7,750 RPM, using up to 12 pounds of boost to give us the 150 horsepower.
So, how does it work? It is a four-stroke, so you instantly notice the vehicle weight. No two ways around it, four-strokes are heavier, especially when we add a turbo and intercooler. And, they are quieter, easy on fuel, and deliver exceptional long term durability, reliability and consistency. No secrets here, but we should all be reminded of why there continues to be an attraction to a heavier snowmobile. When used in environments where the snow is packed (trail riding) they can be made to perform quite well. The Renegade X-RS 900 ACE Turbo easily delivers the best ride and handling of any four-stroke snowmobile, simply due to the Gen 4 REV platform, rMotion rear suspension and the X-RS shock package. No surprises there, it says X-RS on the hood so we know what to expect, and it delivers. We were actually surprised at how well the chassis and suspension package performed, as it exceeded our expectations. This is a well balanced machine, masking the true weight very well and able to take on rough terrain with relative ease. It is surprisingly easy to ride for long distances, with less rider fatigue than what we expected. We’d (personally) opt for different skis than the adjustable Pilot TS skis but the unit seemed to follow lines better with the added ski pressure, thanks to the added engine mass.
When we get to the engine performance, we have mixed feelings. On paper one would expect a 150 HP four-stroke to pull your arms out of their sockets and snap your head back with the flick of the throttle. This isn’t the case. Those familiar with how the Ski-Doo 900 ACE and 1200 4-TEC engines act with their electronic iTC (intelligent Throttle Control) know what we’re talking about here. Gone is the direct-connection throttle cable between your thumb and the throttle body. Your thumb varies an electronic potentiometer, two of them in fact for redundancy, and the sled’s ECU computer senses the lever position and how quickly the throttle is opening or closing to determine exactly when and where to position the throttle valve for air flow – and acceleration. You do not directly control the throttle opening – the computer does – based on your actions. It’s a software thing, and getting the programming just right takes time and effort. Instead of a linear relationship between where your thumb places the throttle lever on the handlebars and how quickly the throttle valve actually opens down at the engine, the software cushions your inputs for a smoother, more controlled action to even out the power delivery of the mighty turbocharged triple.
This takes some getting used to. Again, those familiar with the current 900 ACE or 1200 4-TEC know what this iTC system feels like and acts like. It is not a ultra-snappy or instant power delivery, rather more of a measured and controlled one. You really have to push on the throttle lever to get much of anything to happen. Once you’re rolling things are much happier, but you find yourself having to do most of your driving in the last half of throttle travel, or movement. This is a weird sensation for those of us accustomed to the head-snapping response of a two-stroke, and even in comparison to the quick-responding Yamaha Sidewinder Turbo. These are very different engines in how they apply the power. Know this. Where you can get the Yamaha to full power output in a matter of seconds, it takes the 900 ACE a bit longer to arrive at that destination. At first we wondered if it was simply turbo lag, but we believe it is far more due to how the iTC throttle control system is designed and programmed to provide a more controllable and predictable power delivery. In this manner it is very forgiving, and makes high-speed blasts much more deliberate. Track spin is reduced, directional changes are more predictable and the entire ride experience ends up being more confident.
Mind you, these are all prototype machines that we have been riding, and with each version the iTC throttle system has been progressing through the development stages and keeps getting better with each rendition. You have to get used to how the power is delivered, but once you acclimate you will find it to be a most enjoyable and capable trail sled with incredible bump capability and handling response for a four-stroke. We fully expect the final production calibration to be even more refined than what we are reporting on here, but would expect much of the same character to be retained – smooth, linear, controllable power, easy to ride for hundreds of miles per day, regardless of how rough the trail might get.
The key here is that after 10,000 miles we would be willing to bet that 98% of the 900 ACE Turbo motors will be running with nothing more than an oil change at the end of each season, where we just don’t know how many two-stroke engines would be running at that point. Veteran riders are looking for even more reliability and consistency, but don’t want to sacrifice ride and handling capability. That, my friends, is why Ski-Doo is offering the 2019 Renegade X-RS 900 ACE Turbo – 4-stroke reliability and ultra efficiency, with the trade-off being the added weight and complexity. Ride on.
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