[AMC-list] Electric Power Steering

[Jesse <j2sax@xxxxxxxxx>]

Yeah, one of the most common is the rack that is on the Pontiac G6 and the other same size GM vehicles.  

Did you know the first completely self-contained , electronically controlled rack was to steer the REAR of the GM pickups with Quadra Steer.  Those were the trucks they used to shown backing up with a boat in a figure "8".  The input system would sense what speed and direction the truck was moving and, if at low speeds, the wheels would turn opposite the front to make it reduce the turning radius and make it more maneuverable.  At highway speeds the wheels would turn the same direction as the front to make for easier/smoother lane changes.  It was a giant rack bolted to the rear end with nothing connected to the steering system but a plug.  

 Mechatronics is a newly coined term for controls that were previously mechanical that are now driven by electronically controlled electrical motors.  Electrical-over hydraulic power steering pumps, electric racks and gears, electronic throttle bodies, and soon electrically controlled BRAKES! (imagine a drive-by-wire vehicle where there is no more connection between you and the steering and brakes than a video game!) Oil pumps, vacuum pumps, parking brakes, fuel pumps are just a few more examples of where this is headed.  

Due to this, the high amperage alternators are becoming more of a draw since so much more is being required of the electrical system.  


Jesse


" From: Jesse <j2sax@xxxxxxxxx>
" 
" There are LOTS of newer vehicles that have electrically boosted power
" steering as well as completely electronically controlled, electrically
" powered steering racks.  Most of your later model GM mid size vehicles
" have them (06 and up) as well as many other vehicles available here.
" No need to pay over the pond shipping for something you could get here!

i expect hydro ps to become rare, if it isn't already.  now that
york-style a/c compressors are a thing of the past, a ps pump is the
3rd biggest load on the engine after aero drag and drivetrain/road
friction.  [which rules depends on speed - friction around town, aero
on the highway]

remember, the pump is pumping all the time keeping the system
pressurized, even when you're not moving the steering wheel.  and it's
a fixed-displacement pump so it's always putting out full volume even
if the steering gear isn't using it, and it has to be sized big, to
supply the steering even at idle, like when parking.

a variable-displacement pump could approach electric ps for
efficiency, but not in cost or maintenance.  electric ps isn't just a
newfangled gimmick.

semi-relevant factoid: the shuttle flight control system - the rudder
and ailerons and main-engine gimbals - were hydraulically actuated,
and the pumps took 400hp just to maintain working pressure. 
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