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To make a long story short, it didn't work out. Even though it was a "true" manual rack, it was still way too stiff to turn my fat front tires. (it would probably be perfect with skinnies)
So - I started looking at options. Turns out that a fair amount of racers, and also folks who have converted their car to be completely electric, have been using a Toyota MR2 Spyder pump to do this. Specifically, you want a pump from a 2000-2005 MR2 Spyder to do this swap. The beautiful thing about this pump is it is 100% self-contained - the pump AND reservoir are one single unit.
As opposed to newer cars that have "electric steering", which is notorious for lack of "feel", this is "electro-hydraulic". You are keeping the feel of the hydraulic rack, but getting rid of the mechanical pump, long hoses, bracketry, remote reservoir, etc. It's a very clean install.
The pump has circuitry that causes it to switch to an "idle" mode when no load is being sensed. I haven't tested how much current it uses, but it hasn't blown a 30 amp fuse yet, and I'm using it to turn 18" wheels that are 10" wide with 285 tires.
The pump also has circuitry for picking up on vehicle speed, but I'm not using that currently. It appears most of the conversions don't use this either.
If you are interested in doing this, you will need the following parts:
1. Pump
2. 2 AN fittings for the steering rack - I bought mine from Turn One - see here: https://www.turnone-steering.com/col...ering-fittings If you buy the fittings from Turn One you need 1 "TUR6" and 1 "TUR5" These are male fittings that screw directly into the steering rack.
3. 1 AN fitting for the pump itself - I used a Russell fitting, part number 670531 - see here: https://www.summitracing.com/parts/rus-670531 This is a male fitting that screws directly into the Toyota pump.
4. High pressure hydraulic line - any competent hose shop can make this - you simply need -6 AN female 90 degree fittings on the end. Obviously, depending on how/where you mount the pump, this determines the length of the hose and the "clocking" of the fittings relative to the hose itself. In fact, the first hose I had made I had to change the clocking 90 degrees - the high pressure hoses do NOT have any "rotational" flexibility - in other words you need to nail the "clocking" of the fitting the first time. (though the hoses are relatively cheap, I think my hose shop charged me $70 or so)
5. Low pressure line - this is a simple rubber hose with a -6 AN female fitting on one end and "open" on the other
So - on to my install. I chose to mount the pump in the well below the driver's side headlight. (my smog pump is long gone) Obviously, this is probably the best location since it's close to the fittings on the rack. However, the pump is compact enough where you could put it just about anywhere.
From a wiring perspective, it's pretty simple. You have a heavy duty power wire, heavy duty ground, and 2 smaller power wires that power the internal relays in the pump. I used a 40 amp relay on the fat power wire. The 2 smaller power wires are fed 12V once the car is running by picking up on the fuel pump signal. (which also means the pump primes once I turn key to first position, just like the fuel pump does) That's how I did it, you could do it virtually any way you wanted to, even use a switch if you liked.
Note: my car is heavily customized, so I have a lot of wiring going on in the area near the pump. On a "factory" car, this area looks quite a bit different.
Here is a view directly from the top. You can see all 3 bolts that are used to mount the pump - luckily the 2 on the left matched up exactly with 2 of the holes for the air dam, so I used those holes:
Here is a better view of the pump body. At the bottom left, you can see the metal pipe (from Lowes) that I used as a support. There is an identical pipe support at both of the other bolt holes. However, the pipe support on the far right in the picture I had to shorten, and cut a slight angle, to make it better fit the fender well.
Also, at the lower left, below the metal pipe support, you can see a flat piece of steel that I used to give more support to the pump mounting. There is another flat piece of steel on the bottom side.
Here's a view of the steering rack:
So how does it drive? Personally, I LOVE it. I actually think it feels better than stock, especially at speed. I always HATED the "floaty" feel of stock C4 steering. It is a "tad" heavy at low speed, but you can certainly turn the wheel with one hand no problem.
A couple other newer cars use that type of system, I should keep track of the models. That was a short run of MR2s, so your not going to find that unit easily.
A couple other newer cars use that type of system, I should keep track of the models. That was a short run of MR2s, so your not going to find that unit easily.
You might think that, but there seems to be a lot of the pumps around. In fact I bought 2 at the same time to have a backup, and I'm probably going to do the same setup on my M5.
There's a crapload on ebay right now. You can also use an older MR2 pump, but the 2000-2005 is the hot setup.
Porsche has a nice pump that's really similar, but of course it's $$$$$
I don't know of any newer cars that are "electro-hydraulic" - most of them have an electronic servo on the steering shaft, so there is no hydraulic component. Those are the ones that are notorious for lack of steering feel.
What pressure does this pump produce? I'd think that contributes much to maybe the "low speed" drive-ability. Could it be controlled by an orifice of sorts or is their maybe a way to increase the flow control of this pump?
I believe a fellow here local has maybe used a Volvo creation for something similar on a project car.
What pressure does this pump produce? I'd think that contributes much to maybe the "low speed" drive-ability. Could it be controlled by an orifice of sorts or is their maybe a way to increase the flow control of this pump?
I believe a fellow here local has maybe used a Volvo creation for something similar on a project car.
That's a good question. Obviously, the MR2 has much smaller tires and is a lighter car, so I'm asking a lot of the pump. I figured I would see how it went and if they start dying on me left and right I'll try the Porsche pump.
I don't think you can increase the flow, only decrease it through the use of a VSS signal.
would this return a couple more hp that hadbeen soaked up by the drive pulley ps pump?
I would think so, especially since the pump goes "idle" when it doesn't sense load, and so you aren't really using much power when you are running straight down the highway.
You might think that, but there seems to be a lot of the pumps around. In fact I bought 2 at the same time to have a backup, and I'm probably going to do the same setup on my M5.
There's a crapload on ebay right now. You can also use an older MR2 pump, but the 2000-2005 is the hot setup.
Porsche has a nice pump that's really similar, but of course it's $$$$$
I don't know of any newer cars that are "electro-hydraulic" - most of them have an electronic servo on the steering shaft, so there is no hydraulic component. Those are the ones that are notorious for lack of steering feel.
The mazda 3 uses a similar system, I don't think its been used in custom cars as much though. I wonder if these systems could operate a hydraulic cooling fan at the same time.
What pressure does this pump produce? I'd think that contributes much to maybe the "low speed" drive-ability. Could it be controlled by an orifice of sorts or is their maybe a way to increase the flow control of this pump?
I believe a fellow here local has maybe used a Volvo creation for something similar on a project car.
Just found a link that claims 1200 psi
Also - you have me thinking now. Turn One has "restrictors" and even a "variable flow" controller, gonna shoot them an email.
No free lunch, converting mechanical power to electrical and then back to mechanical there are losses. That being said from the description "It is a "tad" heavy at low speed" I'd say it pumps less so the cost would be less. From a drag race perspective it's something you can flip off and back on when you leave the track, but you still have weight vs total manual rack. If I ran any type of high speed track I might experiment with an rpm/window switch to kill it with higher speed, to try n get every last bit of power.
Great info! I've been looking for something like this for my lemans. Also looking for an electric ac compressor for the same car. I can't find anything near the capacity of the original one though.
Great info! I've been looking for something like this for my lemans. Also looking for an electric ac compressor for the same car. I can't find anything near the capacity of the original one though.
If you figure out something for electric ac I would love to know how . . .
It wouldn't even have to work fantastic, just take the edge off. That will be one of my next projects. I would love to have easily removable ac.
01-28-2017, 09:25 PM
Converted my car to use an electric power steering pump
