I worked for a company that made the machines that electromagnetically
formed the metal bands on the rubber boots for the front drive shafts. GMC
made lots of rolling changes during the development of the Tornado front
wheel drive car.
Most of the smaller front wheel drive cars of that time all had torque
steer, but it was not a problem because their torque was small and it was
easy to overcome with the steering wheel forces and dampers. It was accepted
at that time that front wheel drive was only a solution for small cars with
low torque engines.
When GM started their big front wheel drive designs, nobody knew how to
solve the problem of torque steering. Torque steering was a major problem
with the high torque front wheel drives. Unsolved torque steer with a large
torque engine can rip the steering wheel right out of your hand to the full
hard over position at any speed, particularly with intermittent traction.
The problem occurs when the slipping tire instantly regains traction. You
can still sense a slight torque steer in the GMC Motorhome when that
happens.
GM spent a lot of development time solving that torque steering problem.
Their final solution resulted in a lot of unique front end geometry
compromises to tame the torque steer forces.
I recommend to anyone changing the front wheel offset to add torque steer
testing. It may surprise you with the amount of steering wheel yank the 340
ft-lbs of torque can developed with the now offset loads when the traction
is instantly regained. The real problem is that that situation can occur
when you least expect it.
As a started, talk to the young men who have put very wide offset tires on
their front wheel drive Honda's, which have no where near 340 ft-lbs of
torque.
Chuck
formed the metal bands on the rubber boots for the front drive shafts. GMC
made lots of rolling changes during the development of the Tornado front
wheel drive car.
Most of the smaller front wheel drive cars of that time all had torque
steer, but it was not a problem because their torque was small and it was
easy to overcome with the steering wheel forces and dampers. It was accepted
at that time that front wheel drive was only a solution for small cars with
low torque engines.
When GM started their big front wheel drive designs, nobody knew how to
solve the problem of torque steering. Torque steering was a major problem
with the high torque front wheel drives. Unsolved torque steer with a large
torque engine can rip the steering wheel right out of your hand to the full
hard over position at any speed, particularly with intermittent traction.
The problem occurs when the slipping tire instantly regains traction. You
can still sense a slight torque steer in the GMC Motorhome when that
happens.
GM spent a lot of development time solving that torque steering problem.
Their final solution resulted in a lot of unique front end geometry
compromises to tame the torque steer forces.
I recommend to anyone changing the front wheel offset to add torque steer
testing. It may surprise you with the amount of steering wheel yank the 340
ft-lbs of torque can developed with the now offset loads when the traction
is instantly regained. The real problem is that that situation can occur
when you least expect it.
As a started, talk to the young men who have put very wide offset tires on
their front wheel drive Honda's, which have no where near 340 ft-lbs of
torque.
Chuck
