This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Colorado State University Clean Snowmobile Challenge 2002
Technical Paper
2002-01-2758
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
A student design team at Colorado State University (CSU) has developed an innovative snowmobile to compete in the Clean Snowmobile Challenge 2002 competition. The team selected a 600cc two-stroke cycle engine (Arctic Cat ZRT600) due to its favorable power/weight ratio. In order to reduce emissions, the team adapted the engine to operate with direct in-cylinder fuel injection, using the Orbital Combustion Process (OCP) air-assisted fuel injection system. This conversion required that the team design and cast new heads for the engine. The direct-injection system reduced carbon monoxide (CO) emissions by 70% and total hydrocarbon (THC) emissions by 90%. An oxidation catalyst was placed in the engine's silencer to oxidize the remaining CO and hydrocarbons. The combination of direct injection and oxidation catalyst reduced both CO and THC by over 99%. In order to reduce noise, the team switched from the use of three expansion chambers (i.e. “triple pipes”) on the stock ZRT600 to a single expansion chamber. An exhaust silencer was then fitted to reduce exhaust noise, and a new intake airbox was designed to reduce intake noise. A layer of acoustic foam was applied to the interior of the engine compartment to reduce radiated engine noise. An acoustic analysis of the engine shows that the noise level of the snowmobile is dominated by noise at the engine's firing frequency and at twice the firing frequency. Quarter-wave reaction tubes were fitted to the intake and exhaust to reduce noise. The steps taken reduced the noise from the unmodified level of 83 dBA to 75 dBA, which did not meet the competition requirements of 74 dBA. Direct injection has improved the fuel efficiency from 13 miles per gallon (MPG) with the unmodified engine to approximately 20 MPG. The performance of the engine has been improved. The peak horsepower has been reduced by approximately 4 horsepower due to the switch from triple-pipes to a single pipe exhaust. However, the engine torque in the mid-range has been increased, and the throttle response is improved across the entire range. These factors combine to give the direct-injected snowmobile the same elapsed times in a 500-foot acceleration test as the unmodified snowmobile. In summary, the CSU snowmobile has reduced emissions by 99%, reduced fuel consumption by 35%, reduced noise by 8 dBA, and improved overall performance and ridability. A cost analysis has shown that the team's technical approach would add approximately $497 to the cost of manufacturing a snowmobile.

Recommended Content
Authors
- Tim Bauer - Team Members, Colorado State University
- Michael Duncan - Team Members, Colorado State University
- Nathan Lorenz - Team Members, Colorado State University
- Dan Mastbergen - Team Members, Colorado State University
- Steve Nelson - Team Members, Colorado State University
- Nick Peterson - Team Members, Colorado State University
- Jessica Rupp - Team Members, Colorado State University
- Brian Wedryk - Team Members, Colorado State University
- Travis Mathis - Team Members, Colorado State University
- Bryan Willson - Faculty Advisors, Colorado State University
- Patrick Fitzhorn - Faculty Advisors, Colorado State University
- Steven Schaeffer - Faculty Advisors, Colorado State University
Topic
Citation
Bauer, T., Duncan, M., Lorenz, N., Mastbergen, D. et al., "Colorado State University Clean Snowmobile Challenge 2002," SAE Technical Paper 2002-01-2758, 2002, https://doi.org/10.4271/2002-01-2758.Also In
References
- Coates S W Lassanske G G “Measurement and Analysis of Gaseous Exhaust Emissions from Recreational and Small Commercial Marine Craft.” SAE # 901597
- Blair Gordon P Design and Simulation of Two-Stroke Engines SAE International 1996
- Heywood J B Sher Eran The Two-Stroke Cycle Engine: Its Development, Operation, and Design SAE Taylor & Francis 1999
- Control of Snowmobile Noise 1 Technology and Cost Information 1974
- SAE Clean Snowmobile Challenge 2002 rules
- Kirkpatrick Alan T Ferguson C R Internal Combustion Engines - Applied Thermosciences Second Edition John Wiley & Sons 2001
- McDowell A. et al. “Catalyst Deactivation on a Two-Stroke Engine” SAE paper # 982015
- Blair Gordon P Design and Simulation of Two-Stroke Engines SAE International 1996
- Heywood J B Internal Combustion Engine Fundamentals McGraw-Hill 1988 652
- Wright C W White J J “Development and Validation of a Snowmobile Engine Emission Test Procedure.” SAE # 982017
- Bishop Gary “FEAT Equations for CO, HC, and NO.” February 2002
- SAE standard J192 “Exterior Sound Level for Snowmobiles.” March 1985
- Eisenhauer K “Durability Development of an Automotive Two-Stroke Engine.” SAE paper #956006 1995
- Shawcross David Pumphrey C Arnall D “A Five-Million Kilometre, 100-Vehicle Fleet Trial of an Air-Assist Direct Fuel Injected, Automotive 2-Stroke Engine.” SAE paper # 2000-01-0898