Shift time

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 transferred to the next selected gear, and engine speed is reduced or increased to synchronize the speed of the next gear. Shift time is usually in reference to motor vehicles, but can apply to any gearbox. Shift time is measured by the time it takes for the engine rpm to synchronize with the next gear input speed target. This is illustrated by ZF, describing the 100-300 millisecond shifts of their DCT transmissions.[1]

Reducing shift time is important in performance and racing vehicles because upshifting 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 execute fast gear changes. Historically, a dual-clutch transmission 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 and transfer torque from one clutch to the next clutch with the pre-selected next gear, thus reducing shift times. Standard planetary automatic transmissions have caught up to DCT transmission shift times by also utilizing clutch to clutch shifts. For older transmissions, 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.

With a manual transmission, upshift time can be reduced by installing a lighter flywheel. During an upshift, the engine speed must decrease to synchronize with a higher gear; a lighter flywheel will allow the engine speed to drop more quickly, leading to shorter shift times.

Shift times

  • A long shift time is considered anything over 625 milliseconds.[2]
  • The average manual car driver takes between 500 ms and 1 s to perform vertical gear changes (i.e. 1st-2nd, 3rd-4th, 5th-6th) and 1 - 2 s to perform horizontal gear changes (i.e. 2nd-3rd, 4th-5th). Shift time is also dependent on gear throws (distance between gears), ease of movement, ergonomics of the gear stick, and gearbox condition. [citation needed]
  • For reference, the time it takes for a human to blink can be as quick as 100ms[3] (.1 seconds)

Example upshift times

Please note that some manufacturers may have different definitions of shift times, this is not a complete list.

Vehicle Transmission model Transmission type Shift time (ms) Notes
McLaren 675LT 7 Speed SSG Dual-Clutch 40[4] According to MotorTrend Article
Lamborghini Aventador Graziano ISR Automated manual 50[5][6]
Ferrari 430 Scuderia Graziano F1 Automated manual 60[7]
Ferrari FXX Evoluzione Graziano F1 Automated manual 60[8]
Maserati GranTurismo MC Stradale Maserati MC Race Shift Automated manual 60[9] With Race mode active
BMW M5 (E60) BMW SMG III Automated manual 65-250[10]
Ferrari FXX Graziano F1 Automated manual 80[11]
Shelby GT500 (3rd generation) Tremec TR-9070 Dual-clutch 80[12]
Bugatti Veyron Volkswagen Group DSG Dual-clutch 100[13]
Mercedes-Benz AMG GT-Line Mercedes-Benz AMG SpeedShift Dual-clutch 100[14] As little as 100ms, according to MB
Lexus LC 500 Aisin WR10L65 Hydraulic automatic 120[15]
Renault Clio RS 200 EDC Trophy (4th generation) Renault EDC Dual-clutch <120[16] With Race mode active
Chevrolet Camaro ZL1 (6th generation) Ford-GM 10L90 Hydraulic automatic ~150[17]
Ferrari Enzo Graziano F1 Automated manual 150[18]
Nissan GT-R BorgWarner GR6Z30A Dual-clutch 150[19] With R Mode active
Lexus LFA Nürburgring edition Aisin SA6 Automated manual 150[20]

See also

References

  1. ^ "Wayback Machine" (PDF). www.zf.com. Archived from the original (PDF) on 2023-06-01. Retrieved 2024-12-11.
  2. ^ "Tech Tips: Understanding TAP". Automotive Service Association. Archived from the original on 2006-10-03. Retrieved 2006-07-29.
  3. ^ "Blink and you miss it!". www.ucl.ac.uk. Archived from the original on 2018-07-02. Retrieved 2018-11-28.
  4. ^ Walker, William (2016-02-16). "2016 McLaren 675LT First Test Review". MotorTrend. Retrieved 2023-01-26.
  5. ^ "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.
  6. ^ Radu, Vlad (2021-07-02). "The Aventador's ISR Gearbox: How It Works and Why Some Owners Complain About It". autoevolution. Retrieved 2022-09-09.
  7. ^ "SCUD MISSILE Ferrari 430 Scuderia Review". Rush Magazine. Retrieved 2024-12-11.
  8. ^ "Ferrari FXX Evo | Corse Clienti - Ferrari.com". www.ferrari.com. Retrieved 2024-12-11.
  9. ^ "Maserati". www.media.maserati.com. Retrieved 2024-12-11.
  10. ^ Lewin, Tony (30 September 2016). The BMW Century: The Ultimate Performance Machines. Motorbooks. p. 137. ISBN 9780760353042. Retrieved 21 July 2017.
  11. ^ "Ferrari FXX Breaks Cover". Piston Heads. Archived from the original on 2012-02-05. Retrieved 2006-09-23.
  12. ^ "Stunning Performance and Control: 2020 Shelby GT500 Achieves Supercar Acceleration with 760 Horsepower and 7-Speed Dual-Clutch Transmission". Ford Media Center. Retrieved 9 June 2020.
  13. ^ "Bugatti Veyron Super Sport Technical Specifications" (PDF). Bugatti.com. Retrieved 2018-11-28.
  14. ^ "| Mercedes-Benz USA". www.mbusa.com. Retrieved 2024-12-11.
  15. ^ "MY19 Lexus LC500 Sales Brochure" (PDF). Archived from the original (PDF) on 2018-11-29. Retrieved 2018-11-29.
  16. ^ "New Clio R.S. 200 EDC: 'à la carte' sports performance". Renaultsport. Retrieved 2014-03-09.
  17. ^ "Camaro ZL1's Lightning-Fast Transmission is a Perfect 10". media.gm.com. Retrieved 2018-11-28.
  18. ^ "Volkswagen makes way for DSG". Paul Tan. Retrieved 2006-08-11.
  19. ^ "LAUNCH CONTROL: MY20 NISSAN GT-R IS READY FOR TAKE-OFF". Official Great Britain Newsroom. 2019-08-30. Retrieved 2022-10-07.
  20. ^ Clifford, Joe (2020-12-10). "What made the Lexus LFA Nürburgring edition so special?". Lexus UK Magazine. Retrieved 2024-12-11.