The Getrag F28/6 is a 6-speed manual transmission built by Getrag and fitted to the C20LET 2.0L Turbo Opel Calibra.
Features The F28/6 was designed to follow a transverse oriented C20LET engine feeding the front wheels with an outlet to facilitate a driveshaft to feed the rear wheels as well. If the four-wheel drive system is disengaged, the gearbox feeds the front wheels. Conversion kits are available from aftermarket suppliers to convert the 6-speed transmission to suit a front-wheel drive vehicle, and this is a common upgrade (from the 5-speed F20 transmission) amongst owners of the C20XE and X20XEV Calibras.
+ Configuration Clutch diameter 1st gear ratio 3.57:1 2nd gear ratio 2.16:1 3rd gear ratio 1.45:1 4th gear ratio 1.10:1 5th gear ratio 0.89:1 6th gear ratio 0.74:1 Reverse gear ratio 3.23:1 Final drive ratio 3.72:1 (front)3.70:1 (rear)
Designation One interpretation of Opel's gearbox numbering designation is that it refers to the ft·lbf torque capacity, in this case a torque limit. Instead it may be related to the engine size (the F28 gearbox was fitted to a 2.0L turbo engine, with the 1.4 multiplier applied for turbocharged vehicles).
GM transmissions are usually numerically designated in Newton-meters. For example the 6-speed M32 gearbox was fitted to the Opel/Vauxhall Astra VXR H and has a torque rating of (hence '32' designation). The maximum torque output of the Astra VXR engine (Z20LEH) is limited to .
Nomenclature The letter F stands for front-wheel-drive; Although the F28 is only used in 4WD applications, the base transmission still remains a common FWD gearbox. The number 28 stands for the maximum torque capacity in Newton-meters divided by 10; therefore, 28 means that the transmission is capable of transferring nominal torque to the input shaft.
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