On 23/07/2018 12:02, NY wrote:
"Dave Plowman (News)" wrote in message
...
In article ,
* TMS320 wrote:
Turning off the ignition will turn off electric power steering. Not what
you want to add to your list of surprises.

You can still steer the car with no power assistance. It will just be
heavier. But not so heavy you can't steer it to the side of the road. And
far safer than trying to stop the car on the brakes while on full power.

Yes I've driven my car a couple of miles, including changing lanes,
coming off a motorway and going round a roundabout, with no PAS when the
fan belt broke. It was heavy. I had to plan ahead and grip the wheel
with both hands to get more torque on the wheel, but it was not
insurmountable. I wouldn't like to try it in a coach or HGV, though :-)

Is the heaviness of the steering when PAS is disabled due solely to
having to compress the PAS fluid on the "wrong" side of the piston that
gives power assistance? Or are cars with PAS made with inherently
heavier steering (different castor angle) to give greater precision and
feedback to the driver, in the knowledge that the PAS will more than
compensate for this heavier (but more responsive, more self-centring)
steering. I've heard two schools of thought about this.

There may be some hydraulic effects, but there is also a simple
mechanical reason - mechanical advantage. From my experience, non-PAS is
typically 3.5 turns lock to lock, while PAS is typically 2.5

Regards,
SteveW