May 18, 2011
Reverse and Turbos
I logged on this morning and was hit between the eyes with a couple of excellent questions, which when I began to answer, occurred to me I could base a whole post on my thoughts. So without further adieu…
I currently have 6 Yamaha snowmobiles and have just ordered 2-2012 Nytro XTX’s. I like these sleds but the reverse engagement lever is very hard to use. I have tried various ways of using it, including using a strap to pull on it but nothing makes it work any better including adjustment or a dealer working on it. My non Yamaha buddies get a real charge out this. Also Artic Cat, Bombardier, and Polaris have a factory turbo, but nothing from the leading 4 stroke manufacturer, this seems puzzling to me. Having owned at least 35-40 snowmobiles, 90 % Yamaha and 90% of those bought new I would appreciate and answer to these questions. Repectfully yours, Murray, Sask. Canada
Hey Murray, regarding the reverse gear system on the Nytro; it follows suit with every reverse gear Yamaha has designed to date. In a nutshell, it is ‘quirky’, which is odd when you consider the number of gear systems and transmissions to come out of our engineering group. I find it works best if you are left handed, reach across the saddle while looking over your right shoulder and sticking your tongue out of the opposite side of your mouth, simultaneously blipping the throttle. It also helps if Venus and Pluto are aligned… seriously, there is a bit of a ‘knack’ to it, sometimes the gears don’t mesh just right and a small amount of throttle to move the jack-shaft a bit helps, also having the idle speed set correctly as well as the clutch C2C and OE drive belt will keep the gears from being pre-loaded. If everything is set right it comes down to the angles and order of force exerted upon the reverse mechanism. Occasionally it works like a charm, effortless, then the next time I’m in need of some reverse thrust it can be a real struggle. I will pass along your comments to our engineers (it is not the first time they will have heard this one). And a word of caution, don’t be forcing it too much or you may find yourself clutching a broken handle, it’s all about the ‘angle of the dangle’ so to speak.
On the subject of turbos, we have been pushing this one for a while now (pardon the pun), especially for the mountain application where altitude effects horsepower. There is an argument to the point that a low boost turbo can compensate for the loss of power at elevation without stressing the engine beyond its design parameters. Our engineers work to very exacting standards much of which has come about from years of motorcycle design. They will not sacrifice the durability / reliability of the engines to achieve more power with a ‘bolt on’ device. That said, the testing standards we have to meet appear to be quite a bit beyond that of what the real world requires… catch 22.
There is also inherent pride in knowing our current engines, normally aspirated, are very close to the power output of our competitions boosted engines. Historically, Yamaha has dabbled with boost, most recently in the marine side of things, but we tend to shy away from using turbos or superchargers in favor of building state of the art engine technology taken from pages of MotoGP racing development and auto partnerships.
The current market trends and acceptance of boosting smaller engines in autos and the adoption of the technology into more baseline motorsports has got to have an impact on our planning somewhere down the road. The simple fact that we have many engines operating under high boost pressure for several seasons in the mountains tells me our motors can ‘handle it’ and supports my theory that the ‘bench test’ for our sled engines most likely leaves a significant margin of error when it comes to squeezing some more juice for the real world.
To counter the additional cost of boost, the base engines (like those you refer to from our competition) do not have to be as costly to produce, with lower hp/liter output when normally aspirated. This, along with our ‘rule-book’ of engineering standards would most likely conclude, we would have to design a new engine from the a clean sheet of paper to offer factory boost.
I am not saying such a project is under way, in fact I can say, to my knowledge it is not. But one thing is for certain things are changing at Yamaha. Much of this change is a result of the recession and its impact on our business model. Efficiencies, global demands, parts suppliers, exchange rates and not the least, the internet are all having a profound impact on our future. It’s a mighty big ship to turn but I sense some big changes looking over the bow at the shifting horizon.
… Time will tell. Cheers cr