Competiton Paper by dandanhuanghuang


									       University of Maine’s Flex Fuel Capable Four-Stroke
             Joseph Stilwell, Kazuki Iwakura, Eric Whitman, Kevin Bowler
                    University of Maine

For the 2010 Clean Snowmobile             stock engine configuration. Engine
Challenge (CSC), the University of        noise and vibration is reduced using
Maine is submitting a second-             sound absorbing materials around the
generation four-stroke snowmobile         inside of the cowling as well as under
capable of running on flex-fuel.          the seat to prevent noise from the
Through the use of an engine control      exhaust system. The Umaine Phazer
unit (ECU), Microsquirt, the              meets emissions standards through
snowmobile can successfully be tuned      the use of a new catalytic converter
to improve fuel consumption,              and is fuel-efficient.
decrease emissions, and maintain the
Snowmobiles provide outdoor               competition snowmobiles need to
enthusiast the opportunity to             perform at the same level as the
experience the thrill of trail riding     original equipment manufacturer
during the winter months when snow        (OEM) and are expected to
is abundant. Although snowmobiles         significantly reduce hydrocarbons,
provide entertainment, they also          carbon monoxide, nitrous oxide, and
contribute to environmental pollution     excessive noise.
through excessive emissions and they
can be extremely noisy in residential     This paper discusses how the 2010
areas. The Society of Automotive          University of Maine team has modified
Engineers (SAE) developed the Clean       the 2007 Yamaha Phazer Snowmobile
Snowmobile Challenge in 2000 for the      for the 2010 CSC in order to reduce
purpose of re-engineering                 emissions and sound while
snowmobiles to produce fewer              maintaining the OEM performance
emissions, operate quieter, and           and riding characteristics. This paper
consume less fuel through a               also discusses what the team kept
combination of ethanol and gasoline       from the previous years team in a
(flex-fuel). At the same time the         summary form.
Design Goals – The overall goals for      place to compare the emissions
the 2010 clean snowmobile team is to      produced from the stock exhaust
reduce exhaust emissions, mainly HC,      system and the emissions produced
CO, and NOx, and reduce noise and         from the custom exhaust system with
vibration from the snowmobile.            the three-phase catalytic converter. In
Through the use of a five-mode gas        order to reduce noise and vibration,
analyzer, emission testing has taken      sound deadening materials have been
placed around the cowling, inside the     nitrous oxide (NOx). The catalytic
engine walls, and underneath the seat     converter features a 2.25” center
to help reduce the sound and              inlet/outlet pipe, 9 x 5.125” round
vibration from the engine output.         body, and is 13” in overall length.
                                          Figure 1 shows the catalytic converter
                                          mounted onto the customized exhaust
Umaine Design
The Baseline Snowmobile – The stock
specifications for the four-stroke 2007
Yamaha Phazer snowmobile are listed
below in Table 1.

    Engine Type          Four-Stroke
  Cooling Method        Liquid Cooling
      Cylinders                2
       Engine               499 cc
 Compression Ratio          12.4:1
  Maximum Power              80 HP
 Dry Weight of Sled         454 lbs
  Size of Fuel Tank      11.4 gallons
      Fuel Type            E20-E29
Table 1 – Stock specifications of the
2007 Yamaha Phazer Snowmobile

methods to improving the emissions
produced by the snowmobile. The first
method is a mechanical method and
the second method deals with the
electrical wiring of the Microsquirt
engine controller.

Mechanical Method: The 2010               Figure 1 – Custom exhaust system with
University of Maine clean snowmobile      new 3-phase catalytic converter
team chose to incorporate a 3-way
                                          Figure two shows the Yamaha Phazer
catalytic converter into a customized
                                          with the stock exhaust system. The
exhaust system. The catalytic
                                          stock exhaust system was used to
converter used in the customized
                                          compare emission production and
exhaust system is designed for
                                          sound production from the
automotive applications. The 3-way
catalytic converter is a Magnaflow
performance catalytic converter
capable of oxidizing hydrocarbons
(HC), carbon monoxide (CO), and
                                         Figure 3 – Custom muffler with three
                                         chambers and expander

                                         Electrical Method: The 2009 clean
Figure 2 – Yamaha Phazer with stock      snowmobile team chose to implement
exhaust system                           the use of an engine controller,
                                         Microsquirt, for the purpose of tuning
Figure three shows the custom            the engine of the snowmobile to
muffler being constructed to             produce fewer emissions. Microsquirt
accommodate the new exhaust system       allows the user to optimize ignition
with the catalytic converter included.   and fuel delivery parameters to
The muffler consists of three            balance the ratio of ethanol and
chambers with an expander. The           gasoline for better performance as
exhaust will enter the muffler through   well as optimize fuel economy and
a 2.5” opening in the front, move        emissions. The Microsquirt unit is a
through the center chambers while        Bowling & Grippo unit chosen for easy
expanding, and then circulate back       compatibility with the stock Yamaha
through the side chambers and exit       Phazer sensors and for easy
through the bottom of the muffler and    programmability and tuning. The
out into the atmosphere. With the        2009 clean snowmobile team varied
addition of the new muffler, sound       the spark ignition, air-fuel ratio, and
and vibration from the sled will be      volumetric efficiency to determine the
reduced.                                 best combination for optimum fuel
                                         efficiency and emission production.
                                         The 2009 team used Microsquirt to
                                         control the fuel delivery with a
                                         measured air pressure to allow the
                                         most useful mixture of air and fuel to
                                         be delivered to the engine of the
                                         snowmobile. The variability of the
                                         Microsquirt unit can determine the
right ratio of air and fuel to be          decoupler [1]. The Vcomp noise
delivered. If the mixture is too lean      barrier is being used inside the
then the sled will lose power and          cowling as well as around the steering
backfire. If the mixture is too rich the   column and dashboard of the
exhaust produces a heavy black smoke       snowmobile where vibration is an
and the throttle response is very          issue. Shown below are
sluggish. Microsquirt allows these         representations of the B-Quiet
parameters to be adjusted in order to      Ultimate and the B-Quiet Vcomp
find the right mixture for optimal         materials used.
performance. The 2009 team
implemented this unit into the engine
controller and adjusted the
parameters to produce the most
power, fewer emissions, and better
response from the snowmobile.

Shown below are the emissions
produced from the stock Yamaha
Phazer snowmobile.

                                           Figure 3 – B-Quiet Ultimate used under
                                           the riders seat. Rated for high

SOUND & VIBRATION: In order to
reduce the sound and vibration and
the Yamaha Phazer, the 2010 clean
snowmobile used sound deadening
materials that have been placed in and
around known areas where sound and
vibration are prevalent. Two materials
have been used to reduce sound and
vibration of the snowmobile. The first
material used was B-Quiet Ultimate,
which is a 1.6mm thick viscoelastic
deadener rated for high temperature
which is being used underneath the
rider seat where temperature from          Figure 4 – B-Quiet Vcomp composite
the exhaust is highest. The second         noise barrier used under the cowling
material used was B-Quiet Vcomp            and around the steering column and
which is a composite noise barrier         dashboard
consisting of a dense 1/8” vinyl based
polymer barrier with a ¼” thick foam

[1] B-Quiet

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