The FR500S featured a racing version of the 4.6L Ford Modular engine outputting 320 HP (brake / crank) coupled to a Tremec T56R close-ratio 6-speed transmission, while the FR500C featured the 5.0L Cammer R50 engine delivering 420 horsepower , via a Tremec T-56R. FR500 race cars vary greatly depending on what racing series they were designed for.