has anyone here ever tried installing an electric power steering pump into their chevelles? it seems like a good way to free up some horse power and still have the convenience of power steering.

Danny

where do you see this? sounds interesting

im helping a friend work on his electric car and it has one. he said that some fiats came with this pump.

i guess ill be the first...eventually

I keep seeing the Saturn comercials that state they have electric power steering, so maybe their system is worth looking at.

I've actually been giving this some thought lately. I'm not sure how much power is needed to turn the pump when there is a large load placed on it. Like wider front tires, increased scrub radius, cornering, etc. I would like to try this sometime. I was thinking about using one of those electric motors that moroso sells for turning a mechanical water pump. I wouldn't doubt it if an aftermarket company comes up with a kit real soon for this very type of thing. Just like electric fans, if you advertise they'll save you 'x' amount of horsepower, they'll sell like hotcakes, :D .

That would work well if you had a 42 volt system like some of the new cars will have. Using 12 volts, the motor used to turn to pump will draw alot of amperage!

The new 2004 Malibu also has an electric steering unit. I think that the Malibu is about as big as you can go with a 12 volt electric steering unit. The problem is one of power. You may be able to steering slowly with the vehicle rolling. But you would find that you could not steer with the vehicle stopped and you would also find that you could not make a rapid evasive maneuver. Chevrolet is not making many advertizing comments relative to electric steering.

Another thought, in terms of power, you can turn the steering gear with a direct electric motor assist system or you can turn a hydraulic pump and produce hydraulic pressure and flow that provided power to a gear or assist cylinder. But the power required to turn the road wheels is virtually the same. So if you don't have sufficient electric power with a 12 volt system it doesn't make much difference if you power direct or through a hydraulic pump.

As far as driving direct. This sounds much more difficult as opposed to running a electic motor with a pulley directly to the pump pulley. Or am I missing something?

As you gain HP with the Elect pump. Find out if you lose any from the extra load on the Elect chargeing system, Like a larger Alt & Batt. May be less $ to add a few HP to the crank. Elect fans work. Elect water pumps work in the short runs. But in the short runs do they use power steering?
If you keep the front wheels off the ground in the short runs and go straight, You won't need steering. :D
JMOP Bob J.

The company that I work for makes some of the electrically assisted power steering units. They do not use hydraulics.

Unless a system comes out for a heavy duty application I would not put one in my car. The internal components are pretty small.

Try going here: http://www.am.nsk.com/default.asp?ID=124

Click on the "Automotive" car in the center, then select Powertrain from the LH menu, then Electical Power Steering.

Here's a picture.
http://industry.am.nsk.com/assets/images/prdauto_car_stearing2.gif

Originally posted by MarkM:
As far as driving direct. This sounds much more difficult as opposed to running a electic motor with a pulley directly to the pump pulley. Or am I missing something? i think i few people were confused about this. i meant an electric pump still using the stock steering box and components, not a fully electric steering system. im going to look into how many amps it takes to run tomorrow.

Danny

I can't possibly see that the power loss through the stock pump is larger than through the alternator and then through an electric pump. The kW's required to make the fluid move should remain the same, so taking "the long way" through the electrical system doesn't really sound like a power saver. Converting from kinetic energy (alternator belt) to electric energy and then to pressure (electric pump) should result in more losses than the more direct conversion from kinetic energy to pressure in a conventional system. Kinda home made physics here, but makes sense if you think about it. I wouldn't even bother to calculate it anyway.

On the other hand, the advantage would be that it won't put a load on the alternator when the steering isn't used, like when going straight forward like we all like to do now and then. A mechanical pump will always put a load on the engine, at least to an extent. Also, you could just flip a switch to disengage an electrical pump while doing those straight line exercises, just like some people take the pump belt off.

IMO, the power gain will only useful on the strip, and it will be another thing that could break or wear out. After all, electric water pumps are not really recommended for street use either. Due to the power conversion losses, I would also think that the mileage will suffer. All this will, of course, only be of concern if it's a street driven car you'll put some miles on, but it would make sense if if it's a race car and you want to get those last ponies out of it.

I'm still thinking the electric motor operated ps pump would help more then hurt. If the alternator is running anyways to operate your fans (which has been proven to make power), ignition boxes, water pump, etc. then some of it's charge can go to the ps pump motor too, without anymore power from the alt. Isn't an alt. either on or off?

Also when you're running at speed, either on the highway, drag strip, staights on a road coarse, etc. the e-ps pump could be turned off. Perhaps hooked up to a WOT switch to turn it on and off. This switch could also momentarily turn the alt. completely off. Or you could turn the alt. off with a manualy operated switch, allow everything to run off the battery for a short period, and then turn the alt. back on to allow it to re-charge the battery, like on a cool down lap, return to the the pits, highway, etc.

This may sound like alot of work to get a few hp, but if you're wanting to get every last hp out of a combination, it's worth it, IMHO, :D .

It is true that the belt driven power steering pump is always recirculating oil around the system and also internally. So there is always parasitic drag from the pump even though you are not steering.

For everyday useage, if you try and power the pump with an electric motor you are going to have to sense when you need flow and pressure (i.e. when you are steering) so that the electric motor can spin the pump up to 1500 or 2000 rpm. You also cannot stop the electric motor completely when you do not need power assist because you will have a noticeable lag between when you need assist and when the electric motor can spool up to spin the pump and produce flow.

Now if you are just talking racing, you can just charge the battery in the pits, and spin the power steering pump during your runs since you are using stored energy and not the engine to provide power to spin the pump.

Originally posted by MarkM:
If the alternator is running anyways to operate your fans (which has been proven to make power), ignition boxes, water pump, etc. then some of it's charge can go to the ps pump motor too, without anymore power from the alt. Isn't an alt. either on or off? Now, correct me if I'm wrong, but doesn't the (mechanical) resistance in an alternator increase with increased electrical load? If I remember correctly, it's an old racer's trick to have a cutoff switch on the alternator wiring to temporarily reduce the drag when racing, without taking the belt off.

And the reason why electric fans save hp and gas is that they are not always on, they just kick in when needed and don't put a continous load on the engine like belt driven fans do, right?

That is correct. You can't get something for nothing. If an electric motor is spinning your power steering pump the energy has to come from the alternator and/or the battery. The battery has to be recharged as some time.

When the EPA runs a fuel economy test, the car is placed on a dynomometer and the car is run through a cycle. There is no steering. So a conventional belt driven hydraulic power steering system will always impose a parasitic loss since the pump is always spinning and pushing fluid out through the gear valve and back. On demand, electric power steering systems do not create any losses during the EPA test.

The EPA test typically shows about a 1/4 mile per gallon improvement in a small car with a full electric power steering system.

Now in the real world, you have to steer to get from point A to point B, therefore the electric system does impose a penalty. But not during the EPA test.