Sweet Smell of Success! University of Idaho Two-Stroke Dominates National Clean Snowmobile Competition

University of Idaho's snowmobile competing at the 2007 Clean Snowmobile Challenge Lower exhaust emissions is just one factor contributing to the sweet smell of success for 12 University engineering students.

The 12 members of the University of Idaho Clean Snowmobile Competition Team recently earned first place honors at the Society of Automotive Engineers (SAE) Clean Snowmobile Challenge (CSC), where participating students from across the country re-engineer stock snowmobiles to reduce emissions and noise while maintaining or enhancing performance. The competition was hosted by Michigan Technological University March 19-24.

Idaho's CSC team built a high-performance sled that weds a great ride with significantly improved fuel efficiency, lower emissions and less noise. For its innovative tweaking of a traditional two-stroke engine and unique chassis modifications, Idaho brought home the International Snowmobile Manufacturers Association Award for first place; the Gage Products Award for Best Fuel Economy; the Polaris Industries Award for Best Handling; the Society of Automotive Engineers Award for Best Design; the Land and Sea Inc. Award for Best Performance; EMITEC Award for Best Value; and the DENSO Corporation Award for Best Ride. The team shared the Michigan Snowmobile Endurance Award with four other outstanding institutions completing the 100-mile Endurance Run.

University of Idaho also won big for integrity when team captain Nick Harker stopped mid-race to extinguish a fire in a competitor's vehicle. The team was honored with the Founders Award for Most Sportsmanlike Conduct.

The Idaho sled weighed in at 570 lbs, the lightest combustion engine powered snowmobile in the competition; passed the National Park Service (NPS) Noise Emission standard; passed the cold start on the first pull; was second in acceleration (0.2 seconds behind a competing sled that did not pass NPS noise standards); and earned bonus kudos for no maintenance during the week of competition.

University of Idaho students also brought home honors for Best Oral Presentation and Best Paper.

"We won because we had the most well-rounded snowmobile, with lowest weight, stock horse power, low emissions and improved fuel economy due to direct injection. When you put all that together, it's a fun sled to ride," said Justin Johnson, a graduate student mentor for the CSC team. Johnson also credits the team. "It takes a pretty tight team with a lot of dedication and devotion to put all that together and pull it off."

The university's CSC team design incorporates a high-performance custom chassis powered by a modified Ski-Doo 600cc H.O. two-stroke engine. The team adapted an Evinrude E-Tec direct injection (DI) system to the engine. A DI cylinder head with improved combustion chamber design also was fabricated for the engine. Use of direct injection and the improved combustion chamber greatly reduces exhaust emissions and improves fuel economy. Emissions are further reduced through engine tuning and exhaust after-treatment.

Mechanical noise emissions were reduced using vibration absorbing materials on the chassis and hood. The team designed the hood to allow cooling air to circulate while keeping engine noise at a minimum. Exhaust noise is also addressed through the use of a non-standard exhaust silencer.

The University of Idaho team's two-stroke Rotax DI engine, powered by fuel that is 90 percent gas and 10 percent ethanol, racked up an impressive 19.6 miles-per-gallon on the 100-mile course at Michigan Tech's Keweenaw Research Center. Next best mileage was 18.2 mpg by the University of Maine team. University of Minnesota at Duluth earned third with 14.3 mpg; both competitors used four-stroke engines.

The University of Idaho team also hopes to earn a first-ever National Park Certification for a two-stroke engine, a certification based on standards higher than those set by the Environmental Protection Agency. The vehicle has met all the requirements but one. "We are very very close," said Johnson. "Hydrocarbon emissions have to be less than 15 grams per kilowatt hour. Right now we are at 17.9 grams per kilowatt hour. With some engine hardware changes, calibration changes and catalyst development, that number will improve. This year's results show that two-stroke engines are a clean and quiet solution for consumers that still expect performance from their recreational products, and will make the recreational industry, consumers and land managers take a second look at how they view the future of the two-stroke engine."

University of Idaho's Clean Snowmobile Challenge team posing at competition The University of Idaho CSC team includes graduate and undergraduates students working for senior design, graduate design and university credit. They are: Ben Armstrong, of Mackay; C.J. Stock, Cataldo; Ben Hanks, Saint Anthony; Nick Harker, Idaho Falls; Brian Hanson, Orofino; Charles Harding, Jerome; Scott Nedrow, Asthon; Rachel Geerlings, Twin Falls, Idaho and Salt Lake City, Utah; Justin Johnson, Castle Rock, Wash.; Alex Fuhrman, Greenacres, Wash.; Peter Britanyak, Bonney Lake, Wash.; Dylan Dixon, Bow, Wash.; David Polehn, The Dalles, Ore.; Ben Birch, Anchorage, Alaska; Johan Olofsson, Kramfors, Sweden; and Martin Steinberg; team advisers are graduate students Andrew Findlay, McCall; Justin Johnson, Castle Rock, Wash.; and professor of mechanical engineering Karen Den Braven.

The team's efforts were supported by the National Institute for Advanced Transportation Technology (NIATT) at the University of Idaho, Bombardier Recreational Products, NGK sparkplugs, Nextech, Slydog, Fastenal, AMDS, Woody's, Spokane Winter Knights, Jimmy G's Motorsports, Elk Butte Recreation, Red Bull, Karen DenBraven, Scott Findlay, Dan Cordon, Russ Porter, Joe Plummer, Steve Beyerlein, Nathan Bradbury, CBass, Dr. Bubba, Ralphi, E-lab, and many others.

Next year, Challenge participants in the internal combustion division will be required to use fuel that is either biodiesel or E85, a blend of 85 percent ethanol and 15 percent gasoline.

March 27, 2007