The base vehicle was a three wheeled EZ-Go golf cart that was donated to the team. The cart was not functional with the electric motor. Several of the frame members had significant rust damage, and the brakes were locked up; however, this cart provided a good starting point for future modifications and improvements. A picture of the starting cart can be seen below.
The first step in the base case cart preparation was to modify the frame to accept the gasoline engine. A frame was designed to fit under the seat of the cart to which the engine would be mounted. The frame was constructed of 1"x 1" x 0.125" thick steel tubing.
The drive train of the base case cart consisted of the following major components: engine, clutch, chain and tensioner, jackshaft, and axle. The drive train was designed to achieve a top cart speed of approximately 20 mph, to simulate normal golf cart operation. The engine used had a maximum operating speed of 3600 rpm and the rear axle of the cart had a reduction ratio of 12:1. From these constants, a 14 tooth driving sprocket and 10 tooth driven sprocket were chosen to obtain the correct drive ratio for the desired speeds.
The acceleration of the vehicle was controlled by adjusting the throttle. A throttle cable was used to attach the engine throttle to a linkage attached to the accelerator pedal. In order to open the throttle completely, the cable needed to be pulled 0.5 inches. The existing accelerator linkage had 1.5 inches of travel; therefore, a lever was added to reduce travel. The lever was mounted with a bracket that bolted onto the modified golf cart frame. A bushing was threaded onto the throttle control mounting bracket. The lever arm was bolted to the bracket through the bushing, allowing it to rotate freely. The lever attached to the existing throttle control linkage with the ball joint and stud.
After all modifications were made to the base case cart, fuel consumption tests were performed. Under city driving conditions, the cart operated at 13.8 MPG. Under highway driving conditions (sustained top speed), the cart operated at 24 MPG. Under highway driving conditions (sustained mid speed), the cart operated at 30 MPG. Below is a picture of the completed base case cart.
