In 2003 the University of Maine Team started to work on a sled based on a 203 4-stroke Arctic Cat. This project focuses on the improvements to this sled in the noise vibration and harshness area. Initial benchmarking of the performance of our sled will be required, along with testing of the effect of a range of standard and new modifications. Exhaust modifications will not necessarily be emphasized, instead the drive train, mechanical noise, induction and other noise sources will be most likely to be the source of significant gains in noise reduction.
This is perhaps the most important part of the 2006 Clean Snowmobile effort. In the past a test method othjer than the SAE J192 has been used. This test was poorly designed and not repeatable. For the first time the test will be done in a way that we can prepare properly for the competition A good showing on this event should allow us to be in the running for a win at the competition.
Design build and test, as a team, a quieter 4-stroke sled. A basic computer model
of several of the key
noise paths based on literature in the area and previous year's efforts will be
used to design sound attenuation strategies. Evaluation of the exhaust
noise to determine if that is a significant factor in the overall noise from the
snowmobile and determining a method for reducing track noise in particular the
use of low noise components on the idlers and slides. An engineering evaluation of the effect of the induction system on the
overall sound level produced by the
snowmobile should also be included.
Milestones:
| Get the dyno running: September 27, 2005. |
| Purchase the SAE J192 Standard: September 27, 2005. |
| Research CSC rules, testing procedures and past noise reduction projects: September 30, 2005. |
| Review and set up method for performing SAE J192 standard sound testing including approval for use of University Property: September 30, 2005. |
| Preliminary map of sound source identification from snowmobile: October 13, 2005. |
| Write a short report that describes sound and attenuation: October 20, 2005. |
| Design a test method for evaluation of components prior to installation on snowmobile: October 20, 2005. |
| Develop a list of materials: October 20, 2005. |
| Purchase requests complete for all components and materials for testing: October 25, 2005. |
| Demonstration of testing methods to be used in acceptance testing of the modified components: November 15, 2005. |
| Initial design ideas, start on first semester presentation: November 29, 2005. |
| Presentation of first semester results: December 6, 2005. |
| All materials received and replaceable component design complete: December 15, 2005. |
| Begin fabrication and installation: January 24, 2006. |
| Tests on snow with all components in stock and modified configuration: January 31, 2006. |
| Final equipment tested and installed on competition sled: March 3, 2006. |
| Competition Report: March 2, 2006. |
| CSC Competition: March 13-18, 2006. |
| Review competition results and work on final report: April 2006. |
| Set up of projects for final review of project: May 3, 2006. |
| Open house, operational review of project: May 4, 2006. |
| Final Project Report: May 10, 2006. |