Smokey Yunick's Reverse Torque Special
#1
Posted 28 July 2013 - 10:54
Here we attempt to separate the truth from the legends in Smokey Yunick's 1959 reverse-rotation Kurtis-Offy...
Another Look at Smokey Yunick's Reverse Torque Special | Mac's Motor City Garage.com
Advertisement
#2
Posted 28 July 2013 - 23:29
#3
Posted 29 July 2013 - 03:49
Unfortunately this is one of those examples of Smokus Pocus. When an engine is "free revved" with a WOT blip, a large percentage of the engine torque is accelerating rotating masses in the engine - the reaction causing the chassis to roll. When driving - especially in higher gears, the engine is accelerating much more slowly and (hopefully) the majority of the engine torque is being reacted by the output shaft, leaving only a negligible portion to roll the chassis.
I would think that as long as an engine is producing torque whether accelerating, driving at a steady speed etc. the engine will twist in the opposite direction and transmit this twisting torque to the chassis through the engine mounts.
I have heard that some speedway sprintcars are reverse rotation.
#4
Posted 29 July 2013 - 06:01
If the car has a live axle the drive torque will be transferred to the ground as a "jacking" couple and/or directly into the chassis via the axle linkages. Careful design of the linkage arrangement can cancel or even reverse the jacking effect.
#5
Posted 29 July 2013 - 09:43
And a sprintcar engine with 6-1 gearing has a **** load of torque reaction.
Edited by Lee Nicolle, 29 July 2013 - 09:52.
#6
Posted 30 July 2013 - 00:49
This is a much more significant factor than reversing the small inertial reaction of the accelerating engine, especially one with no flywheel and therefore very low rotational inertia.
Edited by gruntguru, 30 July 2013 - 00:50.
#7
Posted 30 July 2013 - 02:42
It is not uncommon to see drag racing cars lift one front wheel off the ground due to the engine torque reaction (assisted by weight transfer due to acceleration).
#8
Posted 31 July 2013 - 11:57
Reverse rotation engines were common place in Sprintcars about 15 years ago. I don't think anyone uses them now. But it was the same theory that Smokey was using.
And a sprintcar engine with 6-1 gearing has a **** load of torque reaction.
I think it's one of those recurring fads in auto racing through the years. Seems to capture peoples' imaginations for some reason.