The R-760E-1, introduced the same year as the R-760E, had a takeoff power rating of 300 hp (224 kW) thanks to higher-compression pistons and a greater RPM limit.

The even more powerful R-760E-2 of 1935 could reach 350 hp (261 kW) for takeoff due to increased supercharging and an even higher RPM limit.

The R-975E-1, introduced the same year as the R-975E, was rated at 365 hp (272 kW) thanks to higher-compression pistons and a slightly greater RPM limit.

The engine in the GT3 version produces around 500 horsepower, likewise in the GTE version, but the RPM limits are 9000, and 7500, respectively.

These had higher compression ratios, greater RPM limits, and more effective supercharging, and they led to the "B series".

During the mid-1930s, Pratt & Whitney developed a still greater improvement of the Wasp Junior, the "C series", with an even higher compression ratio and RPM limit.

Variable rate ignition modules can be adjusted quickly and easily to achieve the appropriate RPM limit for different situations, such as street racing, drag racing, road course racing, highway driving, and lawn turfing.

The second stage is activated after launch to set a higher RPM limit for wide-open-throttle acceleration.

The M12 6-speed causes the Z06 model of C5 Corvette to have a lower top speed than a normal C5 despite having a higher RPM limit and more power, this is due to its gearing.

A three-valve layout allows better breathing than a two-valve head, but the large exhaust valve results in a lower RPM limit.