A high-pressure Zoller supercharger was fitted giving a boost to 2.5 atmospheres (1.8 kg/cc) and allowing the engine to produce  at 7200 rpm. A sprint version was also made with output increased to  which at nearly  per litre was the highest specific output of any engine in the world at the time
A high-pressure Zoller supercharger was installed, boosting the engine's performance to 2.5 atmospheres (1.8 kg/cc) and enabling it to operate at 7200 rpm. A specialized sprint version was created with an output of  which was unparalleled in terms of efficiency per litre.