Construction of Mustang Fever

<<< Go to Mustang Fever Specifications

Mustang Fever was a student project in the Senior level mechanical design class in the Agricultural Engineering Department. Myles Anderson, Russ Angold and Bobby Pierce were the three member team that designed and constructed the Modified Pulling Tractor. Dr. Mark Zohns and Gary Weisenberger were the advisors of the project. Before going into the construction of Mustang Fever we would like to thank our sponsors who made this incredible dream a reality.


Because the construction of Mustang Fever was part of a class project there was a time limit associated. The construction began at the beginning of Winter Quarter at Cal Poly in early January 1999. On March 28, 1999 Mustang Fever pulled the sled for the first time. The first step in the construction process was setting up a jig to hold the frame rails in place around the SQHD differential.

Frame jig showing channel and tube frame convergence around differential.

Once mounting plates were made connecting the frame to the differential it was time to narrow the differential. The differential was cut down with a torch and machined flanges that matched up with the Rockwell Planetaries were welded to each side.

Completed differential.

Cutting splines in the axles.

After completing the work on the differential it was time to mount the Fuller 5-speed transmission. This was done by making a plate that bolted to the front face of the transmission with ears for mounting to each side of the frame rails. With the transmission in place the engine mounts could be made. The engine mounts were made from rectangular tubing and utilized the vertical mounting holes on the Allison Aircraft Engine. With the main power and drive train in place it was time to work on the steering. Steering is achieved through the use of closed system hydraulics. The steering wheel is mounted directly to a low displacement hydraulic motor and the motor is plumbed to a double acting cylinder.

Steering system including stainless steel tubing lines and filling tank.

The next step in the process was the construction of the hitch. As with all the construction components of the Tractor the constraints for the hitch were found in the 1999 NTPA rule book.

Hitch assembly.

The roll cage was bent out of 2" pipe and welded to the frame.

Completed Roll Cage.

The braking system utilizes two-stage master cylinders and heavy duty calipers on machined disks. The disks were designed and built to mount on the drum brake mounting holes of the Rockwell Planetaries.

Planetaries and disk brake set up.

The exhaust from the Allison engine exits through 2- 1 1/2" holes per cylinder. For aesthetic reasons the two exhaust holes were brought together into one 3- 1/2" section of mandrel bent tubing per cylinder. Because the construction of the exhaust system was done by Dr. Zohns they became known as the "Zoomies by Zohns."

"Zoomies by Zohns."

With most of the mechanical system of the tractor completed it was time to run the wires and fire the engine.

Wiring of engine.

Fuel Pressure?


On March 28, 1999 Mustang Fever rolled out of the shop and onto the track. The testing included six hooks in all including one by each of the design and construction team members and both advisors. All in all we could not have asked for a better inaugural performance.

Dr. Mark Zohns getting a "feel for the wheel."

Five days before showtime - powder coated, painted, and polished.

Left to right: Myles Anderson, Bobby Pierce, and Russ Angold

Come see it run at the Cal Poly Tractor Pull!

We would like to thank Dr. Mark Zohns and Gary "Master Machinist" Weisenberger for their many hours of help and their continuing ability to point us in the right direction. Without their help and wisdom, Mustang Fever would have never happened.

Thanks, Mark and Gary!