Backwards Thinking

[firefighter]

I started out driving a non-power steering lil Ford Aspire. When i swiched to my Mazda i was so thankfull for the power steering. But the more i thought about it, the more i relized that pumps are designed backwards. It seems to me that when the power steering is the most usefull is when your sitting in one spot or creaping along, but when your turing 2000 rpm down the high way you dont really need it. So why make the pump run at max when you dont need it and idle when you do??

 

[Wicked_Sludge]

most pumps will provide sufficient pressure to give power assistance at idle. if it doesnt your pump is probbaly worn.

the pumps arent designed to give you the most assistance when you least need it...they just do it by default. they are designed to give sufficient boost so grandma can parellel park, while still being cheap and economical to build. a pump that somehow decreased its drag on the engine as RPM climbed would require expensive and complicated control systems.

 

[firefighter]

I understand that they do work when we need them. Just though it might be a littel more usefull if it could be kicked, sort of like an air conditioner pump, after a certin road speed is achived. This inturn could prolong pump life.

 

[4x4junkie]

Like WS said, the components to control such a system would be expensive and complicated. It would need to gradually ramp up the pump engagement to prevent sudden "bumps" in system pressure as the pump cycled on or off.
With the way so many people in today's society are, someone's gonna get startled by the pump kicking off, resulting in an accident, followed by lawsuits filed against Ford (or anyone that comes up with such a system)

The amount of power the pump uses (and wear on it) at higher speeds is rather minimal anyway. Only when you're turning the wheel does the system build up any pressure.

 

[Wicked_Sludge]

not to mention the reliability factor. the more parts you add to a system, the more failure points it has...and thats the last thing you want on something as important as power steering. as junkie pointed out, can you imagine some soccer mom running her kids to practice when her power steering clutch relay suddenly fails, causing her to loose power steering unexpectedly? reliability is probably the main reason systems like power steering and power brakes havnt changed for, what, half a century?

 

[firefighter]

well good to know
thanks

 

[rocks]

Cars have been made for some time with varible assist power steering. My 350z has it, My 1984 porsche 928 had it. Its nice to have the steering tighten up at 150 mph, it makes it much easier to drive at high speeds. It is more expensive and usually not used on cheaper vehicles. Google it you may be suprised. First post but couldn't resist awnsering this one

http://www.canadiandriver.com/articles/jk/at_010327.htm

 

[bobbywalter]

yeah...its the reason for electric powersteering

 

[4x4junkie]

Cars have been made for some time with varible assist power steering. My 350z has it, My 1984 porsche 928 had it. Its nice to have the steering tighten up at 150 mph, it makes it much easier to drive at high speeds. It is more expensive and usually not used on cheaper vehicles. Google it you may be suprised. First post but couldn't resist awnsering this one

http://www.canadiandriver.com/articles/jk/at_010327.htm

If I'm not mistaken, I think variable assist works by having a variable dump valve (solenoid) or similar at the pump output that regulates the system pressure (pump always spins at engine speed still). This is a little different than the original thought here of having the pump cycle on/off at times in an attempt to prolong the pump's life (at least that's the impression I got when I read firefighter's post).


Welcome to the boards!

 

[Beanmachine7000]

I know I would be kinda weirded out if my power steering went bye bye on the interstate (if I didn't know it was supposed to do that)... I used to drive a manual steer Ranger, I miss it, you felt the road ALOT more, lol... Most people will freak out if they don't have power steering (because you pretty much have to be moving to turn the wheels)... I knew this guy who was a Marine, his power steering broke when he was trying to park and I had to park his car for him, yeah...

 

[firefighter]

yeah...its the reason for electric powersteering

And do they make them for rangers?

 

[firefighter]

i guess not.....

 

[marc11]

And do they make them for rangers?

I have it on my Chevy Equinox and love it. Same power steering feel at any speed.

 

[AllanD]

to quote a line from one of the star trek movies
"the more you overthink the plumbing, the easier it is to stop up the drain"

Ford did exactly what you are describing on some upper level vehicles,
cetain lincoln models, LX and SHO Taurus, etc...

The one thing it accomplished was making the P/S system more failure prone.

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[Wicked_Sludge]

i recently learned that many expeditions were equipped with such a system. its basically an electronic bypass valve built into the pump.