The Bill Thomas Cheetah was an American sports car designed and engineered entirely with American components, and built from 1963 to 1966 by Chevrolet performance tuner Bill Thomas. It was developed as a competitor to Carroll Shelby's Cobra.
Bill Thomas
William P. "Bill" Thomas was born on May 28, 1921, and lived in Anaheim, California. In 1956 Thomas commenced work tuning and modifying Chevrolet Corvettes for racing for C S Mead Motors Co. By 1960, Thomas had started his own company, Bill Thomas Race Cars. At that time General Motors approached him to undertake performance work on the new Chevrolet Corvair. He also prepared the 1962 409 Bel-Airs and Biscaynes for drag racing and another Chevrolet stock car for Louis Unser who won its division of the Pikes Peak International Hill Climb. He was also contracted by GM to develop the Chevy II.
Bill Thomas died October 10, 2009.
Design and development
Prototype
In 1963 Thomas gained covert support from General Motors Performance Product Group head Vince Piggins to develop the Cheetah as a concept vehicle. It was designed by Thomas and Don Edmunds, his lead fabricator. Edmunds is credited with the bulk of the construction of the car. Financing for the project came from private investors, Thomas, and John Grow, a Rialto California Chevrolet dealer. Grow owned the prototype car. Using his racing connections, Thomas arranged for material assistance from Chevrolet for the major components - the Corvette 327 engine, Muncie transmission, and independent rear-end assemblies. Other components were stocked from the larger GM parts bin, such as Chevrolet passenger car spindles, and NASCAR spec Chevrolet drum brakes.
Design and build
Following delivery of the drivetrain components, Edmunds laid them out on the shop floor and began taking measurements. Using chalk, Edmunds sketched the basic outline of the chassis. The original blueprints of the Cheetah by Edmunds consisted of a few simple drawings showing the major components in block form, with major dimensions marked. Edmunds' design methodology for the majority of cars he built during his career was to sketch what he thought a car ought to look like, then build it. Only his last few Indy cars involved professional designers.
Once the chassis shape was determined, Edmunds sketched the body. He showed his drawings to Thomas and after a few minor changes, began construction. The Cheetah was designed to be a cruising machine or styling exercise, not a racing car. Thomas wanted a prototype to show General Motors the level of work his company could do with the intent to obtain additional contract work. After construction began Thomas decided the car would also compete on the racetrack to further promote the concept. The chassis had not been designed for this and therefore was not rigid enough for racing. This problem emerged once the car began to compete.
Once Edmunds had the lower half of a rolling chassis built, he constructed a plywood body form or "buck" on which fit on top of the chassis. The buck included removable metal frames which showed the outline of the windows. Once completed, the body buck and forms were sent to California Metal Shaping for an aluminium body and Aircraft Windshield Co for the windows. Once returned to Thomas', it was finished by Don Borth and Edmunds. A second car was also constructed with an aluminum body in December 1963, for testing by the Chevrolet Engineering Center. The remainder of the cars were bodied in fiberglass.
Production models
The production models used fiberglass bodies. The first were produced by two different companies - Contemporary Fiberglass and Fiberglass Trends. Contemporary Fiberglass was selected to produce the bodies following some problems with the Fiberglass Trends molds. Fiberglass Trends went on to produce their own version of the Cheetah under the name GTR, which was used for drag racing.