Continuously variable transmission. A CVT usually has a low efficiency of 74-75%[need quotation to verify], but it can provide a cheap automatic gear solution by enabling the engine to run at its most efficient revolutions per minute (RPM) for a range of vehicle speeds, allowing a small car (CVT can't handle high torques[need quotation to verify]) to have an acceptable fuel efficiency at low cost. Alternatively, it can be used to maximize the performance of a vehicle by allowing the engine to turn at the RPM at which it produces peak power. This is typically higher than the RPM that achieves peak efficiency. Finally, a CVT does not strictly require the presence of a clutch. Nevertheless, in some vehicles (e.g. motorcycles) a centrifugal clutch is added,[1] to facilitate a "neutral" stance, which is useful when idling or manually reversing into a parking space. Uses[edit] A Chain-driven CVT Principle of Variator Many small tractors for home and garden use have simple rubber belt CVTs.
Some combine harvesters have CVTs. Turbocharger. Cut-away view of an air foil bearing-supported turbocharger. A turbocharger, or turbo (colloquialism), from the Greek "τύρβη" ("turbulence") is a turbine- driven forced induction device that makes an engine more efficient and produce more power for its size by forcing extra air into the combustion chamber.[1][2] A turbocharged engine is more powerful and efficient than a naturally aspirated engine, because the turbine forces more air, and proportionately more fuel, into the combustion chamber than atmospheric pressure alone.
Turbochargers were originally known as turbosuperchargers when all forced induction devices were classified as superchargers. Turbochargers are commonly used on truck, car, train, aircraft, and construction equipment engines. They are popularly used with Otto cycle and Diesel cycle internal combustion engines. They have also been found useful in automotive fuel cells.[4] History[edit] Turbocharging versus supercharging[edit] Operating principle[edit] Turbine[edit]
How a turbo works. Www.powersys.com/system/files/sites/powersys.com/files/EngineSpecificationsGuide.pdf. Gear Ratio for Best 1/4 Mile Time.