Unlike conventional aftermarket turbos that take a second to spool before you get the boost, there is no lag in the turbo on the Sidewinder, thanks in part to Yamaha engineers creating a snowmobile engine that redefines how engines and turbos work together. Instead of one throttle body, they used three, making the 998 the fastest yet smoothest turbo I personally have ever ridden. Plus, it is the first stock 200+ hp engine in a factory-built sled.
The very first time I put the throttle to this beast of an engine, I was amazed with its continuous, linear power. I was equally impressed with how quickly I got to 100+ mph on a sled as large as the B-TX! Even at that speed, it was incredibly stable. The only problem I had was feeling like my helmet visor was going to rip my head off every time the wind got under it.
My favorite feature of this sled is its voice. There isn’t another sound like it on the mountain. AmSnow’s western team compared it to the sound of a jet airplane. Not because it was loud (when you are on it, it is actually fairly quiet), but because it even sounds wicked fast.
See a video of this pull here.
The hard part about building a great crossover sled is trying to find that sweet spot between great handling on the trail and giving the rider confidence when boondocking, swimming in deep powder, or climbing mountains. The B-TX did not disappoint in any of these areas, as it is well suited for high-altitude riding (there’s no loss in horsepower with elevation gain like you see in some boosted 2-strokes). And, while it is equipped to give you a good ride on the trail, the B-TX’s gnarly speed and potent power makes it seem more at home in the hills. On this sled, not taking an opportunity to ride a wheelie up an open hillside almost seems shameful.
I would argue that this snowmobile has a crossover ratio of 80/20. It’s 80% mountain sled, and 20% trail machine by my observation. The trail riders in our crew may disagree, but that’s what we mountain guys want in a “crossover.”
B-TX in the hills
In the mountains and off trail, the B-TX surprised us in a very good way. In the west, we tend to look at anything under a 150-inch track length to be too short, mostly because on a steep-and-deep powder day, you do not want to be the guy everyone has to dig out.