Calculate New Top Speed

This calculator estimates your top speed when horsepower is added. The stock 93 RX-7 was rated at 255 HP at the flywheel and had a top speed of 158. A car's top speed is affected by many things. Higher temperature, humidity or altitude will lower power output and decrease top speed. Lower springs will reduce the apparent frontal area of the car, reduce turbulent airflow under the car and stiffer springs will reduce front-end lift, all of which reduce drag and increase top speed. Adding or enlarging a rear wing will increase drag and slow a car (but the down-force will help road-holding ability and increase speed through corners). Even tire pressure will affect top speed.