Powershifting, also known as full-throttle shifting or flat-shifting, is a method of gear shifting used with

manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canadian English, Canada, British English, the United Kingdom and American English, the United States), or stick shift (in the United States), is a multi-speed ...

s to reduce the time where the driving wheels are not powered. Unlike during a normal gear change, in a powershift the driver does not let off the accelerator. The

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

is briefly depressed while the shift lever is rapidly shifted into a higher gear, keeping the engine in its

power band The power band of an internal combustion engine or electric motor is the range of operating speeds under which the engine or motor is able to output the most power, that is, the maximum energy per unit of time. This usually means that maximum ...

(unlike speed-shifting, where the throttle is let off very quickly, simultaneously depressing the clutch and shifting into the next gear). Keeping the engine in its power band allows it to put down power quicker when the clutch is re-engaged and power returns to the transmission. In a lot of powershift setups there is also a method of cutting the ignition or fuel delivery in a manner similar to a

rev limiter A rev limiter is a device fitted in modern vehicles that have internal combustion engines. They are intended to protect an engine by restricting its maximum rotational speed, measured in revolutions per minute (RPM). Rev limiters are Engine contr ...

, which prevents the engine from over-revving when the load from the transmission is removed. Many aftermarketMegaSquirt ECU
DIY engine management systems. engine management systems provide this functionality as either a standard feature or as an option, usually combined with launch control.

References

Driving techniques {{auto-stub

See also

References