Power Steering?

[rickjames8]

So I work in a building that has a rather tight garage, with rather tight spaces. My car has gotten much easier to steer with the new steering rack, and my column bushing has just arrived, but I am considering trying to adapt an EPS (electronic power steering) column to my car to make it easier to park. Has anyone ever tried this?

It's been done by many other car communities, mostly older hot rods that didn't come with PS. The most common donor columns seem to be the Saturn Vue (same column on the Chevy Equinox, and likely others) and the Toyota Prius (which I think is also used on the Echo and Matrix, and again, likely others). Both of these units can be found for less than $100 on ebay or in your local yard.

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Prius Column link (http://www.ebay.com/itm/2004-2009-Toyota-Prius-COLUMN-STEERING-80960-47051-OEM-/172465995479?fits=Model%3APrius&hash=item2827c63ed7:m:mT_DJh_oIBl2oG67tt0kKwQ&vxp=mtr)
Saturn Column link (http://www.ebay.com/itm/2008-2010-Saturn-Vue-Equinox-Electric-Power-Steering-Column-Pump-Gear-Box-/182375099766?hash=item2a76672d76:g:L9EAAOSwNRdYBp2 d&vxp=mtr)

These don't require an external pump, they are 100% electric. However, they do need to know the vehicle speed to know how much assist to give. Lower speed = more assist, and vice versa. Because most of the older hot rods do not have a VSS, someone has come up with a manual knob that lets you dial in the assist (http://www.ebay.com/itm/Toyota-Prius-04-09-Electric-Power-Steering-Column-Controller-Unit-kit-EPAS-/262400460977?hash=item3d184948b1:g:qVwAAOSw3mpXGlS A&vxp=mtr). While I think this would be a bit annoying, it does solve the problem. One thought I had was to keep the knob dialed at about 80% assist, then hooking the power to a circuit that would engage when the car was in 1st gear (mine is an automatic) and reverse. I have no idea if such a circuit exists for first gear - obviously for reverse I could tap in to the back up light.

I haven't found any reference to anyone trying this, but I don't always search well. I did find a thread about a guy who installs PS for a 4-figure price tag, but no DIY attempts.

So, for your reading enjoyment, here are a few links that got me thinking.
http://www.fordmuscleforums.com/all-ford-techboard/538585-100-power-steering-yes-you-can-use-column-electric-power-assist-system-epas.html
http://forums.vintage-mustang.com/mod-custom-forum/787114-best-200-mod-ever-eps-7.html#post6037649
http://www.pro-touring.com/threads/75149-Electric-power-steering?

[Bitsyncmaster]

My 2005 Chevy Malibu has the best steering feel for any car I have driven. It has the all electric PS. It takes a lot of current when your using it since it's fused at 80 amps. One day I pulled that fuse just to try it. It required a very heavy two hands to make a turn. I would not want to drive that car if the PS ever breaks.

[Jonathan]

You can also experiment with how much air you have in the front tires. Manual says 23 psi for regular driving and 27 psi for continuous highway driving. Turning at low speeds, like into and out of this parking garage of yours, will get better with more air in the front tires. Low air pressures allowing the front tires to grab more pavement will make it more difficult to turn at low speeds. Play around with the air pressures and find out for yourself. It's free too.

[rickjames8]

My 2005 Chevy Malibu has the best steering feel for any car I have driven. It has the all electric PS. It takes a lot of current when your using it since it's fused at 80 amps. One day I pulled that fuse just to try it. It required a very heavy two hands to make a turn. I would not want to drive that car if the PS ever breaks.

Dave,

In some of those other threads I posted, it says that the PS unit 'goes neutral' if you will, when no power is applied. It does not have any resistance of its own. It sounds like you found this was not true of your Malibu.

Also, you seem to be one of the more experienced people with DMC electronics. Is there a way to pick up a signal when the auto trans is in first gear?

[rickjames8]

You can also experiment with how much air you have in the front tires. Manual says 23 psi for regular driving and 27 psi for continuous highway driving. Turning at low speeds, like into and out of this parking garage of yours, will get better with more air in the front tires. Low air pressures allowing the front tires to grab more pavement will make it more difficult to turn at low speeds. Play around with the air pressures and find out for yourself. It's free too.

Come to think of it, one of the tires is a bit low and I keep meaning to inflate it a bit.

[David T]

Dave,

In some of those other threads I posted, it says that the PS unit 'goes neutral' if you will, when no power is applied. It does not have any resistance of its own. It sounds like you found this was not true of your Malibu.

Also, you seem to be one of the more experienced people with DMC electronics. Is there a way to pick up a signal when the auto trans is in first gear?

There is no good way to get a speed signal out of the automatic transmission and even if you could, what do you do for the 5 speeds? IMHO the way to get a speed signal would be to tap into the speedometer cable. Maybe where the Lambda counter is. Remove the counter and put a sensor there. While electric power steering may be a good idea, I would worry about the added load on the electrical system, especially when the alternator is not putting out a whole lot at low speeds. There have been a few attempts at power steering. Do some more research.

[rickjames8]

There is no good way to get a speed signal out of the automatic transmission

David, my plan was not to get a speed signal. Basically, the kit with the knob allows you to set your assist from 0% - 100%. I was going to set it at 80%, leave it there, and hook the 12v+ to a relay that engages only in first and reverse. My assist levels would look like this

1st gear - 80% (regardless of speed)
2nd gear - 0%
3rd gear - 0%
N- 0%
Reverse - 80%

I know when it's in reverse (back up lights are on), I just need to know when it's in first.
You are correct, this would not work for 5 speeds, they'd need to use the knob.

[DMCVegas]

...I am considering trying to adapt an EPS (electronic power steering) column to my car to make it easier to park. Has anyone ever tried this?

It's been done by many other car communities...

And ours is no exception.

http://www.delorean.eu/catalog/product_info.php?cPath=20_143&products_id=168053

[David T]

David, my plan was not to get a speed signal. Basically, the kit with the knob allows you to set your assist from 0% - 100%. I was going to set it at 80%, leave it there, and hook the 12v+ to a relay that engages only in first and reverse. My assist levels would look like this

1st gear - 80% (regardless of speed)
2nd gear - 0%
3rd gear - 0%
N- 0%
Reverse - 80%

I know when it's in reverse (back up lights are on), I just need to know when it's in first.
You are correct, this would not work for 5 speeds, they'd need to use the knob.

To "know" when you are in first gear would require 1 micro switch on the gearshift in the console or 2 anywhere on the shift linkage. Not a big deal to do that. Might also have to put one on the clutch pedal so it will only work when you are moving (for the 5-speed). Before you do this take some basic measurements for fit and travel. Make sure you know what happens in every failure mode too. Steering is a primary control, you MUST have full control AT ALL TIMES under ALL conditions. The other way to go is the more traditional way, hydraulic. A lot more choices but it would require some bracketry on the motor and of course some plumbing. That is what Lotus did later on in their cars and would probably be easy to adapt over.

[rickjames8]

And ours is no exception.

http://www.delorean.eu/catalog/product_info.php?cPath=20_143&products_id=168053

I had seen that, but I can't really justify the $3k tag for how little I'd use it. However, $100 plus some time, I could do pretty easy.

[tommyrich]

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I can confirm that it is possible.
Some observations:
I used the Saturn Vue unit. It is designed for a much heavier vehicle (SUV) and even at the lowest setting, it is a lot of power assist.
Turning off is not a viable option as it is not only stops assisting, but adds additional load from the worm drive motor.
The most amazing thing about the power steering is that it attenuates the feedback from the road (Things like bumps potholes).
Overall, I really like it, but it is not an "easy" mod. and I would advise caution when modifying the steering, unless you know what you are doing.
Tom

[vwdmc16]

Wow that is a very slick install. You have a VSS in place of the Lambda counter I see? I need something like that for my cruise control input.

[rickjames8]

I can confirm that it is possible.
Some observations:
I used the Saturn Vue unit. It is designed for a much heavier vehicle (SUV) and even at the lowest setting, it is a lot of power assist.
Turning off is not a viable option as it is not only stops assisting, but adds additional load from the worm drive motor.
The most amazing thing about the power steering is that it attenuates the feedback from the road (Things like bumps potholes).
Overall, I really like it, but it is not an "easy" mod. and I would advise caution when modifying the steering, unless you know what you are doing.
Tom

That is pure awesomeness!

Your comment about the load when off goes against something I thought I read elsewhere - I'll have to go see if I can find it and see if it was about the Prius model specifically. The Prius is obviously much lighter, so perhaps that also equals less assist.

So how do you control the amount of assist? VSS? A knob? Something else?

[tommyrich]

So how do you control the amount of assist? VSS? A knob? Something else?

I purchased an interface kit (ebay) that comes with a potentiometer to controls the amount of assist. I found that the lowest setting was best so I simply replaced the potentiometer with a fixed resistor.
Tom

[tommyrich]

Wow that is a very slick install. You have a VSS in place of the Lambda counter I see? I need something like that for my cruise control input.

That's actually the opposite. It is a motor driving the speedometer. It replaces the lower cable and angle drive.
Tom