Electric power steering pump / Variable PS

[joeyg1973]

So I was looking around the web for an electric power steering pump. I wound up coming across this website.

Toyota MR2 Power Steering System

So I wound up looking around for some more info about the electric PS pump for a 91 - 95 Toyota MR2. Turns out that this sucker puts out 2000 psi when it is running full speed and takes about 60 amps under full load. That isn't bad at all and could be supported by any 100 amp alternator. Well that's great I thought and began to look around for all the parts. Turns out that getting parts in the US from any junkyard now is damn near impossible and is ridiculously over priced. It's more economical to pull the motor and crush them or in the case of most Toyota's, ship them to Central or South America for parts. Best I could do was $200 plus shipping for just the pump. This would be ok because I also found this sight to run just the pump.

DriveEV.com: JeepEV - Jeep Cherokee EV conversion

But then I just did a google search and I got lucky. I found everything I needed, PS pump, PS Computer, PS Driver, and the Steering Sensor on ebay in the UK. Even with the weak dollar and the cost of shipping I got everything for $160.

I haven't put this in my truck yet, and don't expect to for a few months, but this should work fine. I will post up some pictures of what I got shortly and I am going to put up a wiring diagram that will turn off the PS Computer and turns the pump on high full time for off-road/rock crawling. What I am expecting is that this will gain me a good amount of extra power as well as boost my MPH a good deal. It will also simplify PS installs as you wouldn't have to worry about belts or mounting the PS pump.

There is one peculiarity in the setup that I can tell. There are a few different types of PS Motors/PS Computers combinations that were used.

• For 91 and 92 they used a four wire connection for motor high, motor low, ground, motor bad/fault wire.
• For 93 they used a 3 wire connection for motor high, ground, and motor bad/fault wire. ( This is the one I got. )
• For 94, 95 they used a 2 wire connection for motor high and motor low.

If anybody wants help locating these parts, PM me. I believe that I can get all the parts including the wire pigtails needed for about $250.

Joe

[CruisinGA]

Why?

[John Smith]

Originally Posted by CruisinGA

Why?

My guess is to be different and find out if it works. I look forward to your write up. I would buy and carry a spare pump and any other parts that are unique to that system.

[Poser]

Originally Posted by joeyg1973

What I am expecting is that this will gain me a good amount of extra power as well as boost my MPH a good deal.

Really?

How do you figure? Presuming you do not have power steering currently, how does not removing any parasitic accessory drag from the belt drive currently equate to better MPG?



The marginal amount of parasitic drag of a power steering pump spinning under virtually no load, ie. while cruising down the highway, is not something that you are going to feel in the seat of you pants when removed from the system.

Originally Posted by joeyg1973

It will also simplify PS installs as you wouldn't have to worry about belts or mounting the PS pump.

In all honesty, if fabricating a power steering pump bracket and getting a belt properly aligned is a challenge and something that would be worth worrying about, then perhaps getting someone else with more experience with this type of modification involved in the project might not be that bad of an idea. After all, it is not just your safety in the balance when you are on the streets.

Originally Posted by CruisinGA

Why?

Perhaps the poster ran across “nine page technical rant” Will Byars dissertation about the virtues in converting a Land Cruiser to diesel-electric......










Good luck with the conversion. I hope that it is reliable and safe.

[Jetboy]

It's an interesting idea. Might be an option for rear steer in a situation where running lines back is difficult and remote mounting of a second pump would be lighter, and/or more reliable.

[joeyg1973]

Originally Posted by CruisinGA

Why?

If you have to ask why I can't explain it to you.

[camcruiser13]

give it a go mate

[joeyg1973]

Originally Posted by Poser

Really?

How do you figure? Presuming you do not have power steering currently, how does not removing any parasitic accessory drag from the belt drive currently equate to better MPG?

The marginal amount of parasitic drag of a power steering pump spinning under virtually no load, ie. while cruising down the highway, is not something that you are going to feel in the seat of you pants when removed from the system.

In all honesty, if fabricating a power steering pump bracket and getting a belt properly aligned is a challenge and something that would be worth worrying about, then perhaps getting someone else with more experience with this type of modification involved in the project might not be that bad of an idea. After all, it is not just your safety in the balance when you are on the streets.

Perhaps the poster ran across “nine page technical rant” Will Byars dissertation about the virtues in converting a Land Cruiser to diesel-electric......

Good luck with the conversion. I hope that it is reliable and safe.

I want to reduce the parasitic drag as much as possible and considering I want power steering, this would reduce it. I can fab up metal, electronics, computer programs, wood, plastic, fiberglass, etc without any problem. On my last 40 I did a Scout II PS conversion that ran down the highway like it was on rails. I never said my fab skills were poor, this is just using newer technology that is in fact becoming more and more prevalent in newer cars and trucks. It is a lot easier to mount the items under the hood, connect the wires, and plumb the pump to the steering gear than it is to create a bracket from scratch and find the proper pulley and belt IMHO. If I bought a mechanical pump kit for the 2f it would cost just as much as this setup is costing me.

The reliability of these pumps is excellent. They outlast the lifetime of the MR2 by a whole lot. Toyota built these things right, you can replace the brushes on the motor without ever taking it apart. Taking it apart is trivial too, no special tools required. Wiring this pump up with the PS computer, the PS driver, the steering sensor, and the VSS means that it will only turn on the pump when I am going slow and I am turning the wheel.
I don't need to rev up the engine to get more pressure from the pump while rock crawling or moving slowly because off-road I will have it switched to high full time. This pump also has 2000 PSI which is about 400-600 more PSI than any expensive HO mechanical pump running at full tilt off of the engine that I have encountered. Keep in mind to get max PSI out of a mechanical pump you need to rev the engine which in turn needs to be in neutral so that it can rev it this high and not go anywhere just to turn the wheel.

As for safety going down the highway, it is just as safe as any Saginaw steering gear. Same thing that happens when a mechanical pump stops working applies here. You no longer have power steering and still have full manual control. I am using another Scout II Saginaw gear.

I don't need to carry around a spare pump any more than a truck with a mechanical pump.

Like it or not, these days electronics and electricity are longer lasting, more reliable, and cheaper than mechanical by a long shot.

And yes I can come across as a snarky prick even though it is not my intention.

Any more questions or clarifications needed?

[Poser]

Again, good luck.

[bobsworld2062]

And yes I can come across as a snarky prick even though it is not my intention.

Any more questions or clarifications needed?

Great answers... It's nice to see someone which a sense of humor... I hope that this works well for you!

[rusty_tlc]

I have the same problem with this that I do with electric air pumps.
To pump using electricity;
Step one convert mechanical energy to electrical energy with the associated loss due to efficiency.
Step two convert electricity back to mechanical energy, again with losses due to efficiency in both the motor and the pump

To pump with direct drive;
Run the pump, one set of losses due to efficiency in the pump.

[Poser]

Originally Posted by rusty_tlc

I have the same problem with this that I do with electric air pumps.
To pump using electricity;
Step one convert mechanical energy to electrical energy with the associated loss due to efficiency.
Step two convert electricity back to mechanical energy, again with losses due to efficiency in both the motor and the pump

To pump with direct drive;
Run the pump, one set of losses due to efficiency in the pump.

Dan-


Are you serious?

You cannot bring that kind of thought to this party.....

[rusty_tlc]

Originally Posted by Poser

Dan-


Are you serious?

You cannot bring that kind of thought to this party.....

What was I thinking

[vtcruiser60]

Cheers buddy for trying something new.

I can't add much technical help, but I did think to check the definition of efficiency on wikipedia.....

Efficiency - Wikipedia, the free encyclopedia

[bsmith123]

Sounds like it could be a nice set up this newfangled lectricity thing
Might really be worth it if the install is easy and it is reliable
The only thing that worries me is 60 amps sounds like a lot of power draw if it is constant but That is probably peak load, one winch I looked at draws 85 amps at 2k pull for comparison.

Now here's another idea---couldn't a hydraulic winch be run off this thing also?

Show us how it's done!

[joeyg1973]

Originally Posted by rusty_tlc

I have the same problem with this that I do with electric air pumps.
To pump using electricity;
Step one convert mechanical energy to electrical energy with the associated loss due to efficiency.
Step two convert electricity back to mechanical energy, again with losses due to efficiency in both the motor and the pump

To pump with direct drive;
Run the pump, one set of losses due to efficiency in the pump.

So then, why is everything in heavy industry run on diesel electric then?

Why are these pumps coveted for use in racing applications?

Why are all the manufacturers rapidly moving to this setup?

A quick search on ebay motors shows 3 electric power steering pumps from 3 different car companies, Subarau, Mazda, and Cadillac.

electric power steering pump, Parts Accessories items on eBay.com

Either I am onto something here or I am the dumbest smart person ever.

[bsmith123]

I think we can all relate to the concept of simple, reliable, proven on this site if nowhere else! so I can understand the dissent


yet if it works out we all get a peek at a new way to do it.

Doesn't appear to me from the post that he's asking for an opinion or help, just I'm doing this if you want to check it out, probably will not end up on my rig but I can dig it!

[joeyg1973]

Originally Posted by bsmith123

Sounds like it could be a nice set up this newfangled lectricity thing
Might really be worth it if the install is easy and it is reliable
The only thing that worries me is 60 amps sounds like a lot of power draw if it is constant but That is probably peak load, one winch I looked at draws 85 amps at 2k pull for comparison.

Now here's another idea---couldn't a hydraulic winch be run off this thing also?

Show us how it's done!

Yes I am also thinking of using this for a Mile Marker winch. It also only pulls a full 60 amps on start up. Once an electrical motor is running it actually uses significantly less energy. Applying load to it will cause more amps but no where near 60 amps needed to start up.

From Wikipedia:

Brushed DC Electric Motor - Wikipedia, the free encyclopedia

As an unloaded DC motor spins, it generates a backwards-flowing electromotive force that resists the current being applied to the motor. The current flow through the motor drops as the rotational speed increases, and a free-spinning motor has very little current flow. It is only when a load is applied to the motor that slows the rotor that the current draw through the motor increases.

"In an experiment of this kind made on a motor with separately excited magnets, the following figures were obtained:
Revolutions per minute 0 50 100 160 180 195 Amperes 20 16.2 12.2 7.8 6.1 5.1 Apparently, if the motor had been helped on to run at 261.5 revolutions per minute, the current would have been reduced to zero. In the last result obtained, the current of 5.1 amperes was absorbed in driving the armature against its own friction at the speed of 195 revolutions per minute."
(1917) Hawkins Electrical Guide. Theo. Audel & Co., 359.

[Poser]

Originally Posted by joeyg1973

Either I am onto something or I am on something....

Originally Posted by joeyg1973

Yes I am also thinking of using this for a Mile Marker winch.

All doubt has been removed; you are on something.








Again man...

Good luck with this, and please, start a thread with the build up.

[chattfj40]

Originally Posted by joeyg1973

Why are these pumps coveted for use in racing applications?

I'll take the low hanging fruit...In a racing application the idea is to get the most HP you can and by stripping everything off the belt drive you gain HP, which when .001 seconds counts in a NASCAR race it makes sense...On an FJ40, not so much.

I really can't imagine that you'd pick up any noticable difference in MPG, even on a wind tunneled dyno. The key being the wind...you have noticed that an FJ40 isn't the most svelte body style right? This reminds me of the old windows down or AC fuel economy question.

I'm running both a GM pump and a york compressor, and I can't tell a difference when the york is on, or off from a power standpoint...

But like Poser said, build it, write it up and

[watrob]

I thought very seriously about going Electric motorised FJ rather than diesel.

What stopped me was DISTANCE, how far from the beach house I could go before I ran out of electricity, the problem was SIZE, WEIGHT of cable, energy lose, plus room required for the energy source.

This is what I came up with

[Degnol]

I've seen that setup on pulling trucks to hold on to every ounce of HP and torque the engine can supply. Are you strictly offroad, as in dedicated trail truck?

Ed

[wdorry]

It's not a bad idea but it still takes an amount of HP to drive the steering gearbox to do it's work. So I might be wrong but the ALT will need to work that much harder to produce the ELECTRIC to turn the electric pump. The alt is belt driven so I don't see any gain. No matter what you do the engine is still making the HP to do the steering. Bill