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
0
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)
0
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