University of Wisconsin Madison

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University of WisconsinMadison
2006 SAE Clean Snowmobile Challenge Design
Presentation

• Presented by
• Gary Diehl
• Adam Schumacher

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Design ConsiderationsMarket Survey

• Survey in Fall 2005
• 75 student riders
• Customers Want
• Acceleration
• Agility
• Historical Best Sellers
• Ski-Doo Rev Platform
• Polaris 600 XC SP
• Top speed not given high priority

• Fall 2005 Survey
• (Experienced Riders)

75 Students Surveyed
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Engine Selection
Snowmobile Engine Emissions Testing

• Engine emissions from 2002 and 2003 CSC and
  current commercial snowmobile engines
• Ski-doo SDI system reduces two stroke emissions
  by 501
• Polaris FS engine has lowest emissions of
  commercially available engines

SwRI 2002 (Leda, White)
1 http//www.ski-doo.com/media/2004_SOTY.pdf
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Powertrain Implementation

• Engine Mounts
• Rubber vibration isolation mounts in non-parallel
  planes
• Optimal center to center clutch distance

• Air Box
• Shaped to maximize air flow and minimize size
• Covered with sound dampening rubber
• Intake location chosen to minimize induced air
  temperatures

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Powertrain Implementation

• Clutch Tuning
• Replaced secondary clutch with high-efficiency
  roller clutch
• Replaced spring and weights to match power vs
  clutching

• Stock FS Oil Reservoir
• Ensure correct oil flow and oil reserve volume
• Coated with reflective material
• Oil cooler placed near vents to efficiently cool
  the oil

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Emissions Reduction
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Emissions Benchmark

• 2005 Emissions Testing Results
• 94 reduction from stock
• 86 reduction from 2004

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Emissions Reduction

• Improvements for 2006
• Closed loop at all engine speeds
• Exhaust system re-designed to minimize weight and
  risk of pre-catalyst leaks
• In-line Dual Catalyst System

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Emissions Reduction

• CSC 2006 Emissions Results
• Low CO and HC emissions at WOT
• Engine cleanest at WOT
• Similar emissions as our 2005 best emissions
  award winning snowmobile

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Sound Testing
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Sound Pass By Testing
Track Skirt
Hood Barrier
Contributions of Components to Overall Noise
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Frequency Analysis of Sound
Engine
1st order Track
2nd order Track
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Sound Reduction
Track
Engine

• Two Stage Exhaust System
• Catalysts
• Three Chamber Broadband Muffler
• Increased muffler vol by 60

Silent Track
Tunnel Stiffeners
Direct Sound Barrier
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Resonance of Tunnel
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Total Sound Reduction

• Predict Sound Power Level of 77.2 dBA sound power
  based on Pass by Testing, which meets SAE
  Standard J192
• Track noise greatly decreased by installation of
  Arctic Cat Silent Track
• Engine noise appears to be the only audible
  snowmobile sound, showing reduction of track noise

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Additional Features

• GPS
• Displays street maps that include gas station
  locations

• Evaporative Emissions System
• Reduces HC Emissions from thermal cycling of fuel
  tank

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Projected Cost

• Only 300 higher cost than stock
• Based on 5000 sleds per year
• Difference between 700 and 900cc 2 stroke Polaris
  Snowmobiles
• 900 for a 15 increase in power

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Questions?
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Battery Construction
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Emissions Testing Modes
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Emissions
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Emissions
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(No Transcript)