[richw]

I thought that he was clear he did not really mean "double clutching" but rather slipping a clutch during an acceleration phase.

If you slip the clutch so that the vehicle stays in the motors maximum power band that is feed it enough clutch so the rpms don't drop off or rise to much. Assuming there isn't a rear tire smoke show then your going as fast as you can. If there is any doubt this is not health for most of the components to do this

"Double Clutching: is the act of trying to match the gear speeds up or down with the engine and vehicle motion by reving or slowing the transmission by clutching it into the motor. In the mean time the driveshaft is spinning as the vehicle rolls along.

Single clutching on an up shift of a non syncro tranny will have the motor and input shaft speed drop to idle whilt the tail stock is still spinning at speed. So if you know your vehicle and have a tach (so that's why there there other than "ain't it cool") then you can "double clutch once to neutral rev up or down second clutch new gear ) match MPH with RPMs of that gear and it slips in like BUTTAH.