The chassis of a race car has a number of functions that are required of it. It must act as a framework from which major components such as the engine, suspension, steering and axles can be mounted and held together in place. The chassis must be strong enough to take suspension loadings with minimal deflection and the inertial forces of heavy components together with aerodynamic forces, braking forces and torque reaction forces. All of this to be done while combining the greatest possible torsional rigidity with minimal weight. The Formula 750 chassis has many good design features along with a few things that I feel require modification. The chassis is constructed of box section steel in two sizes. Inch box is used for most of the chassis but 2inch box has been used for the lower chassis members. This is very important as the lower chassis members of a vehicle are put into a lot of tension from the bending forces imposed upon them. These forces are even more considerable in an open top car. The sills have got to support the forces of the engine and driver between the front and rear axles. For this reason larger section box is used and as the bending resistance of box section increases with the cube of the distance from the centre, if you double the size of the box the bending resistance increases by a factor of eight. This larger section box however, is not consistent with the inch box that is used for mounting the engine on. Although the engine is relatively light I would recommend using the larger section. Also these rails are butted up to the larger section box and welded. Although the weld is strong, the area around the weld is weakened and due to the inertial and torque reaction...
pages: 3 (words: 767)