Misplaced Pages

Latest revision as of 22:28, 11 December 2024

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Shift time" – news · newspapers · books · scholar · JSTOR (September 2022) (Learn how and when to remove this message)

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.

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.
• 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.
• For reference, the time it takes for a human to blink can be as quick as 100ms (.1 seconds)

Example upshift times

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

See also

• Powershifting
• Shift kit

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.

• Automobile transmissions