- Shift time
Shift time refers to the time interval between
gear changes in a transmission during which power delivery is interrupted. This is usually in reference to motor vehicles but can apply to anygearbox . Reducing shift time is important in performance vehicles orrace car s because it means the vehicle is rolling without power to the wheels. Shift time in a manual gearbox is dependent on the driver but in automatic or semi-automatic cars the electronic mechanism must be tuned to minimize the time between gears.One method of drastically reducing shift time is to use a
Direct-Shift Gearbox which has two independentclutch es that predict the next gear change making the shift time very small. Using afreewheel may reduce shift time as it may not be necessary to use the clutch. Ashift kit is also intended to reduce the shift time of a manual vehicle.In a
manual transmission car, shift time for upshifts can be reduced by installing a lighterflywheel . During an upshift the engine revolutions must fall for the same vehicle speed; lighter flywheel will cause the revolutions to drop faster when the engine is unloaded, leading to shorter shift times.hift times
*A long shift time is considered anything over 625 ms [web cite|url=http://www.asashop.org/autoinc/aug2004/techtips.cfm|title=Tech Tips: Understanding TAP|accessdate=2006-07-29|publisher= Automotive Service Association]
*The average manual car driver: 500 ms - 1 s Fact|date=February 2007
*Aston Martin Vanquish : 250 msweb cite|url=http://paultan.org/archives/2006/06/26/vw-phases-out-automatics-makes-way-for-dsg/|title=Volkswagen makes way for DSG|accessdate=2006-08-11|publisher= Paul Tan]
*Ferrari 575M : 220 ms
*BMW M3 E36 with SMG I: 220 ms
*Audi TT Quattro 3.2 (Direct Shift): 200 ms [web cite|url=http://www.evo.co.uk/carreviews/evocarreviews/34737/audi_tt_32_quattro.html|title=Audi TT Review|accessdate=2006-07-29|publisher=Evo Car Reviews]
*Ferrari 360 : 150 ms
*Enzo Ferrari: 150 ms
*Ferrari FXX : Under 100 ms [web cite|url=http://www.pistonheads.co.uk/news/default.asp?storyId=12602|title= Ferrari FXX Breaks Cover|accessdate=2006-09-23|publisher=Piston Heads]
*BMW M3 E46 with SMG II: 80 ms
*Ferrari 430 Scuderia & FXX Evoluzione : 60 ms
*Volkswagen Golf GTI (Direct Shift): 8 ms
*Bugatti Veyron (Direct Shift): 8 msSee also
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Powershifting References
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