Shift time

From Wikipedia, the free encyclopedia
For other uses, see Time shifting.

Shift time refers to the time interval between gear changes in a transmission. This interval is the time in which power delivery is interrupted and engine speed is reduced or increased to synchronize speed for the next selected gear. Shift time is usually in reference to motor vehicles but can apply to any gearbox. Reducing shift time is important in performance vehicles or race cars because the shifting process generally interrupts power delivery to the wheels. Shift time in a manual gearbox is dependent on the driver, but in automatic or automated manual cars the electronic or hydraulic control system must be calibrated and tuned to deliver a fast gear change.

Generally, a dual-clutch transmission (DCT) automatic shifts faster than a standard hydraulic automatic transmission with a torque converter, or a single-clutch automated manual transmission. This is possible because the DCT can pre-select the next gear change and switch between two separate clutches to the next pre-determined gear, thus reducing shift times. Using a freewheel may reduce shift time as it may not be necessary to use the clutch. A shift 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 lighter flywheel. During an up-shift the engine speed must fall for the same vehicle speed; a lighter flywheel will allow the engine speed to drop more quickly when it is unloaded leading to shorter shift times.

Shift times[]

  • A long shift time is considered anything over 625 ms[1]
  • The average manual car driver: 500 ms - 1 s (vertical gear changes e.g. 1st-2nd, 3rd-4th, 5th-6th): 1s - 2s horizontal gear changes (2nd - 3rd, 4th - 5th, 6th - 7th). As well shift times can change depending on gear throws (distance between gears), its easement of movement, ergonomics of lever and age of gearbox.[citation needed]
  • For reference, the time it takes for a human to blink can be as quick as 100ms[2] (.1 seconds).
  • The list below only refers to the fastest up-shift time.
  • Please note that manufacturers may have different definitions of shift times, and some times below are not properly cited. List may not be complete.

Official gearbox shift times (fastest to slowest):

  • BMW M3 E36 with SMG I: 250 ms[7]

Other Mentions:

  • AUDI (DSG)(Also S tronic): 8 ms*[circular reference]
  • Volkswagen (DSG)(Also S tronic): 8 ms*[circular reference]
  • Alfa Romeo Mito & Alfa Romeo Giulietta (2010) Dual Dry Clutch Transmission TCT: 8 ms*[15]

*This is an impossibly fast claim which is widely seen on the internet. This number most likely refers to the gear engagement time of the dual clutch transmission, which is the time it takes for the shift fork to select the next requested gear. Actual Up-shift time for the VW DSG and Porsche PDK may be closer to 200ms.

See also[]

References[]

  1. ^ "Tech Tips: Understanding TAP". Automotive Service Association. Archived from the original on 2006-10-03. Retrieved 2006-07-29.
  2. ^ "Blink and you miss it!". www.ucl.ac.uk. Retrieved 2018-11-28.
  3. ^ "Oerlikon Graziano and Vocis Driveline Controls develop step change in transmission technology for new Lamborghini flagship - Oerlikon Graziano". www.oerlikon.com. Retrieved 2018-11-28.
  4. ^ "Ferrari Factory Site".
  5. ^ "Maserati Granturismo MC Stradale (2011) review". CAR Magazine. Retrieved 2018-11-28.
  6. ^ Lewin, Tony (30 September 2016). The BMW Century: The Ultimate Performance Machines. Motorbooks. p. 137. ISBN 9780760353042. Retrieved 21 July 2017.
  7. ^ Jump up to: a b c d e f "Volkswagen makes way for DSG". Paul Tan. Retrieved 2006-08-11.
  8. ^ "STUNNING PERFORMANCE AND CONTROL: 2020 SHELBY GT500 ACHIEVES SUPERCAR ACCELERATION WITH 760 HORSEPOWER AND 7-SPEED DUAL-CLUTCH TRANSMISSION". Ford Media Center. Ford Media Center. Retrieved 9 June 2020.
  9. ^ "Bugatti Veyron Super Sport Technical Specifications" (PDF). Bugatti.com. Retrieved 2018-11-28.
  10. ^ "Ferrari FXX Breaks Cover". Piston Heads. Retrieved 2006-09-23.
  11. ^ "Corvette Shifting Software - Lickety Shift - Vette Magazine". Super Chevy. 2011-12-13. Retrieved 2021-02-18.
  12. ^ "MY19 Lexus LC500 Sales Brochure" (PDF). Retrieved 2018-11-29.
  13. ^ "Camaro ZL1's Lightning-Fast Transmission is a Perfect 10". media.gm.com. Retrieved 2018-11-28.
  14. ^ "New Clio R.S. 200 EDC: 'à la carte' sports performance". Renaultsport. Retrieved 2014-03-09.
  15. ^ "Alfa Romeo UK". Archived from the original on 2011-07-12.
Retrieved from ""