Typical RPM and Torques for an Automatic Transmission

[Anthonyr]

I am looking for RPM and Torque data for automatic transmissions. Can someone give me some typical values or point me in the right direction?

 

[chevy]

I don't really understand your question. Input rpm and torque values are engine output torque and engine values. Torque convertor output torque values are dependent on the characteristics of the TQ. Zero torque at zero engine rpm and max torque at whatever rpm the convertor locks up. I should add that this assumes no loses in the convertor and that older convertor never really completely lock up. I think they achieve about 95-99% lock up. I don't know if the new stuff truly locks up. The same type of analysis goes for the transmission itself...You make an assumption about how much slippage is occuring in the clutch packs. I hope this helps.

 

[GregLocock]

Our torque converter has a lockup clutch, which is electrically actuated as and when the strategy says to do so. It has a limited heat capacity, so you don't use it during full throttle shifts, although once it is engaged it can easily handle the full engine torque. It does not slip at all.

Typical 4 litre engine torque converter characteristics would give a maximum torque multiplication of two, at about 1800-2200 rpm.


Cheers

Greg Locock

 

[rrgmenon25]

Generally for the use of Automatic Gearboxes with torque convertors on commercial Vehicles, the Transmission manufacutrer has a software programme to run and provide u with all details of power consumed, output torque developed, gear ratios, gear change RPMs, heat generated in the torque convertore which has be to added to the vehicle engine cooling system. generally the max. heat condition is considered at a convertor efficiency of 80%. Most Vehicle manufacturers design their cooling system for this value. Otherwise, the torque output from the transmission would then depend upon the demand the vehicle requires, based on load, gradient, acceleration, etc.

The subject is a very intricate one and there are persons who have completed PhDs on some of the parts of an Automatic GB. Suggest you word your question in more detail.