[Chief of the 60's]

Originally Posted by JLMounce

Technically speaking, unless you’re running a lockup converter, your DS rpm will still be less than engine RPM due to torque converter slippage, even if your final is 1:1

But that’s splitting hairs of course.

Not necessarily.

[JLMounce]

I guess if you're on the limit, knowing your slippage across the line would really be necessary. Or calculate backwards from mph and gear ratio to get true shaft rpm.

[AG]

Originally Posted by Chief of the 60's

Just curious. Some do not. That, obviously effects flywheel RPM vs. tail shaft RPM. That effects driveshaft RPM

My converter slips 6.8% across the line so my driveshaft rpm will be slightly lower than flywheel rpm.