On 28 September 1978, Car and Driver technical editor Don Sherman drove a Racing Beat-prepared Mazda RX-7 to 183.904 mph at Utah’s Bonneville Salt Flats, setting a new E/GT class land-speed record. The achievement was particularly significant because the RX-7 was powered by Mazda’s compact rotary engine rather than a conventional piston engine.
Racing Beat extensively modified the car, replacing the standard 12A engine with a 13B rotary enlarged in performance through peripheral porting, a large Weber carburettor and other competition hardware. The engine produced about 326 horsepower for the Bonneville attempt. After an initial mechanical failure, the team returned with a replacement engine and ultimately raised the previous 167.208 mph record to 183.904 mph.
The record helped establish the first-generation RX-7 as a serious performance platform and highlighted the extraordinary power-to-weight potential of Mazda’s rotary technology. Sherman would return to Bonneville in 1986, reaching 238.442 mph with a turbocharged second-generation RX-7.
