Electric Power Steering pump
 

Just finished converting my 1997 S10 to 144v DC. The steering is really hard without the power steering pump. There is no room for a pully off the 9" DC motor. Right now I have the steering rack fittings back on itself and took the pump out of the loop.

Anyone know what size DC motor would be able to turn the Power steering pump? Does anyone make a DC powered power steering pump?

Have you tried looping the power steering lines together so you are not fighting the pump?

If you are set on power steering, do a search for the Toyota MR2. One of the generations had an electric power steering setup. I've seen it used on a few EVs.

Yeah, some MR2s have power steering.
The 2nd generation (SW20, MR2) and the 3rd generation (ZZW30, MRS)
have electric power steering.
Make sure you get the control box as well as the pump. The control box varies the amount of power assistance (depending on car speed I think). Without it the pump will run at full speed all the time using more power and shortening it's life.

Ken

Perhaps you could manually switch the pump on when required? ie when parking or manoeuvering at low speed

The other thing that can be done depending on engine bay space is to get a small DC motor from a treadmill and just use that to spin the existing PS pump. It's extra battery draw, but you could always make it switched - turn on when you're in the parking lot, and off when you're on the road.

Heck, with a little luck and electronics knowledge, you could use an arduino hooked into the VSS to measure vehicle speed, and have it fire a relay to turn the pump on and off automatically at some speed (off if speed is higher than 20 MPH or whatever, and on if speed is lower).

An earlier post on this forum on the same topic.

"Changing from a purely (engine driven pump) hydraulic to an electric driven pump will reduce the power demand by around 80% according to Reimpell , Stoll and Betzler in The Automotive Chassis , p286 in Edition 2.

Power requirements are around 80 amps at full demand , like parking lots for instance , but reduce to the 15 / 20 amps range for suburban driving.
Operating pressures are around 120 bar (1800 psi approx)

Many automotive suppliers (ZF , SKF etc) supply these as complete sub assemblies to car builders so perhaps this may be a good place to begin your search.

Good luck , Pete."

HTH , Peter.

Hi, I'm new to this forum, but I am in the process of fitting electric steering to my VW Transporter van. I bought the whole steering column from a Vauxhall/Opal Corsa and with a bit of cutting and welding it has fitted really well. Ive bought an adjustable controller so I can turn it up when parking etc. In total it has cost me around £100. Cheap and fairly simple to do.

Bigash ,
Welcome and that is a great item for a first post.

Let us know how you progress with the VW conversion.
This is a topic which has been talked about a lot but not too many have actually done the deed.

Peter.

Am I missing something? I can understand that if you have the ability to switch-off an electric PS pump then savings will be made. But if it is running all the time, surely it will be less efficient than a belt-driven pump?

After all - you are first having to use the alternator to convert mechanical energy into electrical energy then convert electrical energy back into mechanical!

On my car, steering is immensely heavy when the hydraulic pump is not running - so if I had, and used, an electrical pump only at very low speeds, I would be in a situation which could be unsafe if I need to suddenly make big steering movements when the pump is not running...

An electrically powered steering column would seem to offer a much better solution - although the conversion could be a bit daunting for most...?

This is my understanding on how these steering columns work.

They are fed by a fairly hefty power wire and earth,and fused with a 60A fuse. They have an ecu with a wire from a speed sensor and a wire from the rev counter plus a fused 3A live and a small earth. The speed sensor varies the amount of assistance. The rev counter wire just tells the ecu the engine is running(I assume so it doesn't drain the battery without the engine running). That's how it works when in the original vehicle.

The controller is just an adjustable potentiometer for the speed signal to vary the assistance.

The system has 3 maps, map 1 is the lowest amount of assistance. When the main power wire is connected without the speed sensor wire the motor works at map 1.

Many people install a 40A fuse as they do not have to turn it up high enough to blow it.

I would assume at its lowest setting(map 1) it would use little power, and would assume a lot less effort than driving a hydraulic pump etc.

Weight wise the column is fairly heavy, but if you stripped your hydraulic stuff out I reckon there may be a weight saving, certainly there would be on an old VW van with the engine in the back! I stripped and weighed my Skyline rear power steering system a few years ago. It had a double pump, one part for front steering, one part for rear. I machined the pump to make it into a front only system and removed half the pump, the lines, and replaced the rear rack with a bar. It all weighed 27KG!

At a guess I would say this system uses an average of 20A at normal driving(nothing when going straight!), so I would say it probably would save fuel. As my van has no power steering I will let you know if I see an increase in fuel use, the trouble is I am also installing a 150A alternator(this may confuse things) as the van has a large stereo(its a party bus!).

I have pics of column if I can work out how to post them.:thumbup:

Ash

Top shaft is the original column that I have removed from it housing....sorry I dont have a pic of both complete columns side by side.

http://i379.photobucket.com/albums/o...36935047_n.jpg

Showing length of both...
http://i379.photobucket.com/albums/o...36935047_n.jpg

Ignition fitted...

http://i379.photobucket.com/albums/o...30944387_n.jpg

Welded 2 ends of columns together....

http://i379.photobucket.com/albums/o...93188857_n.jpg

Brackets welded on.....
http://i379.photobucket.com/albums/o...14588281_n.jpg

Getting there..
http://i379.photobucket.com/albums/o...81038921_n.jpg

Almost done...
http://i379.photobucket.com/albums/o...58139903_n.jpg

I've got an MR2 pump in there, wired to a switch. I didn't get the brain box, so those wires (the clip) are just hanging out in case I want to add it later.
The only time it's even remotely difficult to steer is when I'm at a stop, or very very low speed. The car seems to benefit most from this at highway speeds in terms of mileage, though I didn't do any solid testing to be sure.
What's neat about the MR2 pump is that there is a manual pressure adjustment on the pump, so you can mess with it to find "just enough" assistance when you're not moving.

I haven't yet had any "OH SH**!" moments in which I've needed to turn faster than I am capable. Although it HAS had the added benefit of strengthening my arms a little (I don't actually turn it on very much, only in very tight parking situations).

Would a good idea be to use the pulley off an a/c compressor with the electric clutch and just turn the pump on when needing to turn? Thought about it for a while but never actually tried it.

That could work - it just sounds like it might be more complicated than getting an electric ps pump wired in. Unless you have the materials on hand, in which case, go for it! I'd love to see how well that works!