154 HP 900 ACE TURBO

Did you hear about the new Rotax 900 ACE Turbo? It produces 154 HP with good ol’ 4-stroke torque and reliability. Didn’t hear about that yet? Maybe because it is being offered in the all-new 2017 Can-Am Maverick X3 side-by-side models.

Yes, this is a dirt version of the very same in–line triple ACE 900 found in Ski-Doo snowmobiles and Sea-Doo Spark watercraft, but now fitted with an intercooled turbocharger, and with a claimed 154 horsepower it is the most powerful UTV currently available.

According to BRP, the Maverick X3 reaches its peak horsepower at 7,500 RPM and produces a neck-snapping 113 lb-ft of torque at 7,000 RPM. Combined, this allows the new Maverick X3 to achieve a claimed 0-60 MPH in just 4.9 seconds. Yikes!

BRP says the Maverick features “a highly efficient airflow system that’s optimized from intake to exhaust to deliver superb engine efficiency and performance.” An integrated Rotax turbocharger provides the boost charge to the intake pressure. BRP says its one-piece turbine housing and exhaust manifold offer more durability, along with a new intercooler which features a large fan. Iridium spark plugs come standard with the goal of improving combustion while providing longer life and lower maintenance.

You have to be thinking the same thing we are right about now. What are the chances of this wicked-sounding powerpack ending up in a Ski-Doo snowmobile? Let’s analyze the possibilities here.

The 900 ACE engine, without the extra weight of the turbocharger and intercooler, already weighs more than an 800R E-TEC, which is right there in the same power class. At low elevation, that is. Add the turbocharger and intercooler and we have a good amount of weight penalty over and above the 800R E-TEC, and for sure a hefty penalty over the new 850 E-TEC. But again, this is at low elevation, and a 4-stroke vs. a 2-stroke.

As the operating elevation increases, the naturally aspirated 2-stroke will start to lose power, to the tune of approximately 3% per 1,000 feet of elevation increase. The turbo, on the other hand, pretty much makes the exact same power at any elevation, up to somewhere above 10,000 feet in most cases. So mathematically if we figure 154 HP for the turbo 900 ACE and the 800R E-TEC as a baseline, at 8,000 foot elevation the 2-stroke would be down in power to around 117 HP, or so (3 x 8 = 24% x 154 = 117 HP). The turbo ACE would still be up there at 154 HP. Cool. This is why mountain riders like turbos, both on sleds and on tow vehicles. The blower compensates and makes up for the reduced air pressure at elevation that pushes the air into the engine when you whack the throttle open.

Then there is the 4-stroke vs. 2-stroke argument. Traditionally a 4-stroke is going to offer far better long term durability than a 2-stroke. Now we must consider the advances just made with the new 850 E-TEC and the extra durability features found in the crankshaft, bearings, pistons, rings, cylinders, the entire engine top to bottom was designed to last far longer than any Rotax 2-stroke before, or maybe any 2-stroke snowmobile engine for that matter. Time will tell how long this new powerpack will actually last, but we were told the design criteria was for it run non-stop on the dyno for a minimum equivalent of 12,000 kilometers, which is right about 8,000 miles. By 4-stroke standards this might not be earth shattering, but by 2-stroke standards having a minimum requirement of this duration is hefty and impressive. Again, time will tell, but chances are the 850 is going to be the most durable 2-stroke we have ever seen.

So, it all comes down to what kind of a sled would snowmobilers buy if this 900 ACE Turbo was in fact bolted into a Ski-Doo chassis. Would it be a mountain sled, albeit heavier than a current 800R E-TEC or 850 E-TEC, but with the 4-stroke durability & consistency with no loss in power at elevation? Mountain riders tend to not put as many hours or miles on their equipment as flatlanders, so the durability card might be moot. But, the lure of the 154 HP at any and all elevations would be nice. Then again, Yamaha is offering a 200 HP Sidewinder M-TX, and while we would tend to believe it would be even heavier than a 900 ACE Turbo, we just don’t know. Mountain riders like power but they like light weight. How many turbo 4-strokes do we see out west right now? Maybe we should let that be our guide.

OK, what about crossover riders or MX Z types? We currently have the Rotax 1200 with right about 130 or so HP, and we have the naturally aspirated 900 ACE at 90 HP. The turbo 900 would likely weigh as much if not more than the 1200, so how would that go over? With another 20 HP it would be a nice rocket ship, but we can get better power to weight with a 2-stroke, so the benefit would have to be in the durability department. Adding a turbo tends to reduce the durability to a degree, but it should still last quite a bit longer long term than a 2-stroke of similar power.

Commonality is a huge driver for a manufacturer to reduce production costs, as well as development costs. Having a similar engine in several product lines is nothing new, look at the Yamaha Sidewinder engine as it is very similar to what is found in a side-by-side and watercraft. Yamaha appears to be committed to 4-stroke engines so they choose to not exercise the options like what we find at Rotax and BRP. Thus, we tend to believe that right here right now, unless consumers and dealers alike scream for it, it seems unlikely the 900 ACE Turbo would be offered in a snowmobile. But, do you think Ski-Doo has already fitted one of these engine packages into a snow chassis just to know if it fits or not?