forty4milesaway

SO has anyone run and eletric power steering pump on an fc tried it, thought about it ? I was just curious could you rig up a pump and resevoir to work w/ the stock rack? What pump would work. I was just curious to see if neone has done it or tried to set it up? SO Lets Hear it.

Miles

Aaron Cake

iTrader: (1)

It should be easy to do by belting the proper sized motor to the pump. The problem is that the power steering takes several HP to drive, and a 12V motor of the necessary size is going to be physically huge, and draw around 70A or so. This will certainly ADD weight, and put a major stress on the electrical system (ie. get a big alternator!). A better idea might be to adapt a system from another car. For example, my Honda Insight uses a servo driven electric rack that is very expensive, but needs a complicated control system. I'm really not sure why you would want to do this anyway. Better to just swap on the manual rack.

'Vert in Vegas

If you did it, just figure out a way to turn the pump off above 10MPH.
You only need it at low speeds.

SS124A

just take it off, and watch your forearms start to grow...

slidingsky

I dont think it takes that much power.
I run a haltech so I have no idle assist. At 900rpm I dont make crap for power. So you would deffinetly notice a 10hp drop, especially when trying to start up hill. Even if I turn the wheel while trying to start is isnt that bad.
The new RX-8 uses an electronic rack. Take a look down there. Its probally the same stuff your insight has, right?
It would be nice to find a way to run it electronicly. Im not exactly looking foward to making new lines to fit the pump to a 20b.

Mazdamark

The 2nd gen MR2 used a electric power steering.

Rex4Life

I found an image of what one looks like.

Wish I knew how big it was.

forty4milesaway

I have my power steering removed and i dont think its bad, accept for parking but ull have that. I was just kinda curious to see if neone has done it. Ya the RX 8 has an electric rack would that work in an FC

tweaked

iTrader: (4)

If you find one from a jusnk yard, you have everything already made. You just may have to adapt the fittings for our hoses. I have thought about this too, but there are too many other things I need to finish before I start on that.
But I don't think it will be hard at all.

forty4milesaway

What did that pump come from where did u find it?

SureShot

Look under the hood of an RX-8..

Aaron Cake

iTrader: (1)

That's a really nice looking motor! Looks to be about 1HP or so. Great for a go-kart or scooter...

Note to one of the above posters that I DID NOT say it takes 10HP to drive the power steering. Reread my post.

Still, 1HP is 70A @ 12V, much too large a draw for the stock alternator. Seems like a lot of trouble to go through, especially when there is an excellant manual rack available.

I should also mention that transplanting the system from the RX-8 will probably be difficult, since it is more then likely tied to the ECU (but that's just an assumption).

AREITU

I always thought the MR2 pump was electro-hydraulic. As in, it pumped the fluid instead of just driving the rack by itself. I'm sure with a little monkeywrenching, you can adapt it. Its also easier to source than the NSX stuff.

Aaron Cake

iTrader: (1)

Yes, the MR2 uses basically a pump connected directly to the motor. Lots of EV guys use them. However, they pull quite a lot of current. The limitatin here will be the stock electrical system...

White_FC

The Rx-8 and the MR2 must have HUGE alternators going by these statements then?
but.... do they?? .......the plot thickens....

tweaked

iTrader: (4)

I believe the alternator rating for the RX8 is 120 amps and the MR2 is 100. It doesn't take that much horse power to do this. if it did manufactures wound't bother.
I also don't beleive that you match the draw on motor horse power with the draw of electrical current. I think by just turning the alternator, it is sucking up almost all the power it is going to at 100% duty cycle.
meaning it is sucking lets say 10 HP at 50% duty cycle, but becuase it is already in motion, it may only take an extra 5 horse power at 100%.
The extra current draw doesn't make any real friction. The stator isn't rubbing anything. it is just stationary magnets moving past a coil of wire.
Do you think that there is no power advantage in removeing the stock fan and replacing it with an e-fan. Both take about the same amount of power to spin. But I can't tell a diffrence in accelleration when the fan is on vs off.

rx78788

just wondering how much horse power you loss from the powersterring pump. and if i want to take mine off can i just detach the pelt to it or is they for you have to do to it? thanks

theloudroom

Has anybody looked at the power steering system on the new Saturn Ions?

These have electric power steering pumps.

An electric system would give two benefits:
-less rotating mass (on the engine)
-more flexible mounting options

Rex4Life

That pump is from a Toyota MR2.

Andrew

iTrader: (1)

The RX-8 electric power steering motor directly drives the rack.

Aaron Cake

iTrader: (1)

1 HP is roughtly 745W. So 1HP @ 12V is 62A if the motor is 100% efficient. Since automotive motors are disgustingly inefficient, figure 70% at best, you're looking at over 70A to run a 1HP motor rated at 12V.

The alternator becomes harder to turn as you draw more current from it. Not sure what you're trying to say above, since you don't seem to know the meaning of "duty cycle".

An alternator is not an overunity device. I assure you that the amount of HP it takes to turn will be almost linear to it's output.

[quote]
The extra current draw doesn't make any real friction. The stator isn't rubbing anything. it is just stationary magnets moving past a coil of wire.[/quoite]

Huh? Do you know an electric motor/generator works?

I'm almost willing to bet it takes MORE power for the engine to turn an e-fan then it does the stock fan. The stock fan is directly rotated via the eccentric shaft. An e-fan involves 2 energy conversions (motion to electric, then electric to motion...oh, and there's the electrical losses through the wires, the poor efficiency of the altnernator and e-fan motor, etc.). I have not yet measured this, but plan to...

theloudroom

Everything Aaron has said here is pretty much correct but it doesn't negate the reasons for having an electric ps pump:
-less rotating mass hanging off your engine (whether or now the pump is actually drawing power, you're spinning two pullies, a belt, and who-knows what inside the p/s pump)
-more flexible mounting options
-pump draws ZERO power when you're not steering (...and when you're turning the wheel, you're typically on your way INTO a corner and therefore braking, not accelerating. You don't need much power assist straightening the wheel out again.)

TweakGames

iTrader: (3)

Back from the dead. Sorry.

I want to bring this back up to see if anything else is new? I would like to get rid of my power steering pump and have a more linear power steering system.

Does anybody have any of the pics from this thread from 4 years ago?

Aaron Cake

iTrader: (1)

Just Google Image for "MR2 power steering pump".

The issue is always going to be current draw. It's far easier to just belt off of the engine then install a massive alternator and run an electric pump. Most of the electric power steering systems are a large servo (more efficient then a pump) or use an integrated pump assembly.

You'll still find cars with electric power steering to have larger alternators. For example, in my Insight, turning the wheels lock to lock will cause the DC-DC converter to come on and belt out it's full 70A for several seconds.