Going Green in the Snowmobile Industry

[Vertical_Escape]

Not a chance, as much as i love 2-strokes and will continue to ride them until I die. 4 strokes will be cleaner because they burn more completely by taking twice as many strokes. A 2 stroke can be competitive (especially a triple Etec) but will not be as clean. The funny thing is that as 4 strokes are sweeping across the recreational vehicle market, 2 strokes will soon be re-entering the automotive market. GM is/has been developing a 2 stroke engine for the cavalier. It produced more power and had better fuel economy, but it was just out of reach on NOx emissions

1st off, I doubt the number of strokes has any bearing on smoke/smell. The inherrent design of a 2-stroke assures it will smoke to some degree. You take a 4-stroke with bad rings or valve guides, it'll smoke/smell. Anytime oil is included in the combustion process, smoke will be produced.

The ETEC is being touted as the cleanest, lowest emission 2-stroke. I'm fairly certian BRP has some valid data to backup their claim to that. I know from riding with an XP all season, the newer sleds definately smoke/smell less than my Edges do.

Newer technology=less smoke/smell.

Flame on..........

 

[powdersledder]

Smell is not from the amount of strokes, it is from the engine design. The 4 stroke engine design does not burn oil so there is less smoke and smell.

And the Etec engine is a big step forward for the snowmobile industry. The biggest reason for 2 strokes low fuel mileage is because of both ports being open at the same time, but if you can get the exhaust port closed and inject fuel at the same moment you will be able to have a lot more efficient engine.

 

[Reeb]

Voila!

http://www.motorcycle.com/manufacturer/honda/honda-exp2-14293.html

In the EXP-2, Honda has developed an exhaust port valve which raises and lowers the top of the exhaust port, thereby decreasing and increasing the fuel mixture pressure in the cylinder as needed. This valve is similar in shape to a power valve, but larger, and is shown in detail in these two cut-away diagrams. By setting the valve position based on engine RPM and throttle position, the pressure required for auto-ignition can be achieved at exactly the right timing, causing all of the fuel in the cylinder to burn completely. This process has the added benefit of increasing low RPM power and throttle response, a current problem area with two-strokes.

As a test for this technology, Honda built a 400cc single-cylinder bike for off-road and desert endurance racing. The 400cc single design was chosen because it has a large combustion chamber and a high piston speed, making for difficult burn characteristics; if the EXP-2 system works for this configuration, it will work for smaller piston engines. Fuel injection was also used for ease of setup and fuel measurement, although the system was designed to work with carbureted systems as well. The race results were very good even though the bike was not designed to win races, but to test new technology.

What all this boils down to is that the EXP-2 has about the same real-world performance as the 780, but with substantially better fuel economy and lower emissions.

When the dust settled, the EXP-2 had earned 5th overall and 1st in both the under 500cc and Experimental classes at the Granda-Dakar rally; 1st in the two-stroke class and 8th overall in the Nevada Rally last year, and 7th overall motorcycle at the Baja 1000.

Compared to Honda's current NXR780 four-stroke twin rally race bike, the EXP-2 has very similar performance with several advantages. While the single cylinder EXP-2 produces 54hp to the big NXR's 71, they both make 58 lb-ft of torque, but the EXP-2 is 118 pounds lighter, giving it a slightly better power-to-weight ratio. What all this boils down to is that the EXP-2 has about the same real-world performance as the 780, but with substantially better fuel economy and lower emissions. By increasing the mileage of the bike, it can be raced carrying less fuel, which improves handling and decreases rider fatigue. The problem of unburnt fuel escaping with the exhaust has yet to be solved, but for all you two-stroke die-hards out there: stay tuned, this is the start of something we have all been waiting for.

 

[Weekday Warrior]

Unfortunately I totally agree with CleElum and no matter how clean sleds become they are a dying breed.
I really wish I could take my kid riding to some of the great spots I've been to and see the awesome views I've seen but I KNOW it's not going to happen.
And there's NO WAY of getting to these places on foot, unless you want to make it a 3-day backpacking trip in the summer but the scenery is SO much better in the winter.

I'm not so sure sleds are a dying breed, I'd like to use the PWC for an example, and the issues I've seen with them in the past. 10 years ago PWC's were everywhere on the lake, they were loud and everyone hated them. Now they are so quiet you can just hear the water splashing off the hull and thats it. Now they have increased access to lakes that were once closed to them.

I think sleds will be the same in the future, if manufactures can make them whisper quiet you'll see improved accesses and we'll be able to ride much closer to the 'human powered only' people.

 

[Steve D]

The biggest problem is that the world is over populated. Need to start some one child per family laws like China.

Think about it:
If a sled is blastin' through the woods and nobody is around to hear it, is it really loud?

 

[CleElum Sledhead]

I'm not so sure sleds are a dying breed, I'd like to use the PWC for an example, and the issues I've seen with them in the past. 10 years ago PWC's were everywhere on the lake, they were loud and everyone hated them. Now they are so quiet you can just hear the water splashing off the hull and thats it. Now they have increased access to lakes that were once closed to them.

I think sleds will be the same in the future, if manufactures can make them whisper quiet you'll see improved accesses and we'll be able to ride much closer to the 'human powered only' people.

Really, when was the last designated wilderness area you have seen reopened to sleds? Or even just reopened to quiet 4 stroke sleds like those used in Yellowstone National Park?

And speaking of YNP, now that the manufacturers have developed clean and quiet sleds which are the only sleds even allowed in the park, and you must have a guide to ride them in the park at all, have the extreme green crowd backed off trying to completely close YNP to sleds? Heck no.

I do believe clean and quiet sleds, as long as they still have good horsepower, is a very good thing to strive for. It will take some of the heat off sleds from the middle of the road average joe, but the extreme green crowds will not be happy until sleds are banned from ALL public lands period.

 

[winter brew]

I believe as sled emission requirements get tighter, the power will continue to climb....look at the Doo, Cat and Polaris 800's in the last few years they have gone from 135ish HP to over 150HP all while putting out FAR less polutants. Leaner is meaner (and cleaner!) E-tech takes this a step farther by using even less fuel and oil, the oil consumption is a big part of why the 2-stroke puts out more crap than a 4s.