University of WisconsinUniversity of WisconsinMadisonMadison

Presented by:

Eric Schroeder

Adam Schumacher

2005 SAE Clean Snowmobile Challenge

Design Presentation

Design Considerations:Design Considerations:Market SurveyMarket Survey

Survey in Fall 2003 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 2003 Survey (Experienced Riders)

75 Students Surveyed

Engine SelectionEngine Selection

Engine emissions from 2002 and 2003 CSC and current commercial snowmobile engines

Ski-doo SDI system reduces two stroke emissions by 50%

1

Polaris Liberty engine has lowest emissions of commercially available engines

HCg/kW-hr

COg/kW-hr

NOx

g/kW-hr

Two-stroke average(SwRI 2002) 189 517 0.72

Idaho four-stroke(CSC 2003) 2.1 23.8 5.5

Idaho four-stroke(SwRI 2002) 3.5 152.9 0.19

Arctic Cat 660 (4s) (SwRI 2002) 6.2 79.9 10.6

Polaris Liberty (4s)(SwRI 2002) 3.2 79.1 7.0

1: http://www.ski-doo.com/media/2004_SOTY.pdf

* SwRI 2002 (Leda, White)

Snowmobile Engine Emissions Testing

Powertrain EnhancementPowertrain Enhancement

Hybrid vs. Stock Acceleration Trials

0

10

20

30

40

50

60

70

80

90

0 1 2 3 4

Time (sec)

Tra

ck S

pee

d (

km/h

r)

Normal Acceleration

Hybrid Acceleration

Unique Hybrid Electric Design

•Increases performance without need for larger engine

•Motor mounts to custom student machined chaincase

Measured Performance Increase

•Improves acceleration from 30-60 km/hr

•Does not increase top speed of the snowmobile

Hybrid Energy StorageHybrid Energy Storage

48 Volt Battery Pack 4 Johnson Controls Inspira

Batteries 6.5 Amp-hour capacity

Sufficient for 30 seconds of peak power

Designed to assist the engine during acceleration

Makes the sled “feel more powerful” without added fuel consumption and emissions

Emissions Emissions ReductionReduction

Emissions ReductionEmissions Reduction

CSC 2004 Emissions Results

•High CO and HC emissions at WOT

•Found to be open loop at WOT

•Single catalyst used in 2004

2004 CSC Emissions, UW Madison

0

5

10

15

20

25

30

35

40

Mod

e 1

(WO

T)

Mod

e 2

(85%

)

Mod

e 3

(75%

)

Mod

e 4

(65%

)

Mod

e 5

(Idle

)H

C a

nd

NO

x W

eig

hte

d E

mis

sio

ns

(g

/hr)

0

100

200

300

400

500

600

700

CO

We

igh

ted

Em

iss

ion

s (

g/h

r)

NOx

HC

CO

Emissions ReductionEmissions Reduction

Improvements for 2005

•Closed loop at WOT

•Dual Catalyst System

•Removed Secondary Air Injection0

20

40

60

80

100

14.3 14.4 14.5 14.6 14.7 14.8 14.9

Rich Lean Air/ Fuel Ratio

Ca

taly

st

Eff

icie

nc

y, %

CO

HC

NOx

StoichiometricAir/ Fuel Ratio

Emissions ReductionEmissions Reduction

2005 Emissions Testing Results

•94% reduction from stock

•86% reduction from 2004

UW Madison 2005 Final Emissions Data

0

0.2

0.4

0.6

0.8

1

1.2

Mode

1

Mode

2

Mode

3

Mode

4

Mode

5

Wei

gh

ted

Mas

s E

mis

sio

ns

(g/k

W-h

r)

CO

NOx

HC

Sound TestingSound Testing

Sound Pass By TestingSound Pass By Testing

Percent Reduction in Sound Level From CSC 2004 Configuration

0.0%

1.0%

2.0%

3.0%

4.0%

Right Left Right Left Right Left

Hood Barrier Track Skirt Hood and Skirt

Per

cen

t R

edu

ctio

n

Contributions of Components to Overall Noise

Hood Barrier Track Skirt

Frequency Analysis of SoundFrequency Analysis of Sound

Power Spectral Density (Un-Weighted) Plot of 2004 Configuration of Bucky 800 HD During 7.1 m Pass By Testing

0.0E+00

2.0E-06

4.0E-06

6.0E-06

8.0E-06

1.0E-05

1.2E-05

1.4E-05

1.6E-05

1.8E-05

0 200 400 600 800 1000

Frequency (Hz)

PS

D

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

A-W

eig

hte

d R

ela

tive

Re

spo

ns

e

(dB

)

Right Microphone

Left Microphone

A-Weighting Factor

Engine

1st order Track

2nd order Track

Sound ReductionSound Reduction

Two Stage Muffler System Catalysts Three Chamber Broadband

Muffler

EngineEngineTrackTrack

Tunnel Stiffeners Direct Sound Barrier

Frequency Response of Tunnel Before Addition of Stiffners

0.0E+00

5.0E-04

1.0E-03

1.5E-03

2.0E-03

2.5E-03

3.0E-03

3.5E-03

0 150 300 450 600

Frequency (Hz)

PS

D

Sound Testing Region (35-55 mph)

Resonance of TunnelResonance of TunnelFrequency Response of Tunnel After Addition of Stiffners

and Dampening

0.0E+00

5.0E-04

1.0E-03

1.5E-03

2.0E-03

2.5E-03

3.0E-03

3.5E-03

0 150 300 450 600

Frequency (Hz)

PS

D

Sound Testing Region (35-55 mph)

Total Sound ReductionTotal Sound Reduction

Predict Sound Power Level of 107.5 dBA sound power based on Pass by Testing

43% reduction (2.5 dBA) in sound power level from 2004 Bucky 800 HD

Additional FeaturesAdditional Features

Electronic Throttle Cruise Control Traction Control During

Launch

Evaporative Emissions System Reduces HC Emissions from

thermal cycling of fuel tank

Projected CostProjected Cost

ITEMUW-Madison

Bucky 800 HD

2003 Polaris Frontier Classic

Base sled cost with 784 cc Liberty Four-Stroke

$5,899 $5,899

SLED MODIFICATIONS $60None

Electric Motor and Controller$283 None

Hybrid Battery and wiring$151 None

Catalyst $40 None

Total: $6,433 $5,899

Only $500 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

Questions?Questions?

Hybrid LayoutHybrid Layout

4-Cycle Engine

Motor

Chain CaseTuned

Resonator

Bucky 800 HD Drivetrain Layout

CAT

4-Cycle Engine

Motor

Chain CaseTuned

Resonator

Bucky 800 HD Drivetrain Layout

CAT

Drivetrain TorquesDrivetrain Torques

Total Torque at Track

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100

200

300

400

500

600

700

25 35 45 55 65 75 85

Sled speed (km/hr)

To

rqu

e a

t T

rac

k (

N-m

)

Stock Snowmobile Torque

Motor at secondary

Motor at track

Motor on custom gear

Motor PerformanceMotor Performance

Motor ControllerMotor Controller

Battery ConstructionBattery Construction

Emissions Testing ModesEmissions Testing Modes

Engine Speed (rpm) Torque (N-m) Power (kW)

Mode 1 (WOT) 5600 46.43175 27.229

Mode 2 (85%) 4760 22.44887 11.19

Mode 3 (75%) 4200 15.26523 6.714

Mode 4 (65%) 3600 9.102602 3.4316

Mode 5 (idle) 1100 1.041741 0.12

EmissionsEmissions

Reduction of Exhaust Gas Emissions Through the Dual Stage Catalyst System with Retuned Fuel Injection

(Mode 1, 100% Load)

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200

400

600

800

1000

1200

BeforeCatalysts

BetweenCatalysts

After BothCatalysts

Mas

s E

mis

sio

ns

(g/h

r)

NOx

THC

CO

EmissionsEmissions

Comparison of Exhaust Emissions With and Without Secondary Air Injection (SAI)

0.0

50.0

100.0

150.0

200.0

250.0

No SAI SAI No SAI SAI No SAI SAI No SAI SAI

Mode 1 Mode 2 Mode 3 Mode 4

Mas

s E

mis

sio

ns

(g/h

r)

NOx

HC

CO