University of New Brunswick
The design project chosen by group 3 was to design a suspension system of the Baja vehicle. The system must be able to withstand and work properly in the conditions expected in a typical race that a Baja vehicle would participate in. The system must be within the SAE (Society of Automotive Engineers) rules on the dimensions of the vehicle and safely support the driver and vehicle through any obstacles that the vehicle may encounter. The project has a budget of $3333, which will be used to buy shock absorbers and control arms. To meet the design criteria several design constraints were made. The ride height was set to 6 in. This will keep the vehicle chassis above most obstacles and provide enough distance to prevent bottoming out of the vehicle. All parts to be bought and manufactured have been chosen to fit into the budget. A settling time of the shock absorbers was chosen to be approximately 2 seconds. This will be quick enough to allow the vehicle to recover at a reasonable rate and slow enough to avoid any serious forces or vibrations placed on the driver or vehicle. The camber applied will be negative so to give the vehicle stability at all times. The suspension will consists of an independent system, including one shock absorber for each wheel. The control arms will be double A-arms for the front and back. The shock absorbers selected are fox float R 3. These consist of an air spring instead of a conventional metal spring. The air spring can be easily adjusted and gives a smoother ride than metal coils. The dimensions will be finalized upon completion of the Baja chassis. A dynamic analysis of the system has been done and general outputs of the system have been found and analyzed. Testing of the shocks was done, varying the pressure of the shocks and also changing the masses. The results are analysed.