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Craigorypeck
Craigorypeck New Reader
7/28/17 7:24 a.m.

What modern car is a good donor for electric steering? The rebuilt power rack in my car won't seal as the ram was so pitted from rust. A replacement rack from Germany is over a grand delivered to me in Canada. Back in the UK the Vauxhall corsa was the car that everyone was nicking the E-steering from. Is there a similar go to for components here in North America? Plus I wanna get rid of the PS pump too. Thanks

akylekoz
akylekoz Reader
7/28/17 7:51 a.m.

One fella had an electric rack in a lemons car with a variable assist rheostat, he said it was real easy to wire up. I thing he said it was from a saturn or other GM product. The one in my Mazda 5 looks like it could be used as a stand alone also.

Ian F
Ian F MegaDork
7/28/17 7:57 a.m.

Saturn Vue. The electric columns can be found on eBay for fairly cheap and there's an aftermarket controller module for $55 which allows you to manually adjust the assist. I understand the motor is normally controlled by the car's BCM, so the modules is required to make it work in an older car.

GameboyRMH
GameboyRMH MegaDork
7/28/17 7:59 a.m.

Here are some good American donor candidates:

http://www.fordmuscleforums.com/all-ford-techboard/538585-100-power-steering-yes-you-can-use-column-electric-power-assist-system-epas.html

Since you're never going to use hydraulic PS again, you should do a full rack de-powering which includes welding up the flexible control valve in the lower part of the shaft. This will reduce steering play.

tuna55
tuna55 MegaDork
7/28/17 8:02 a.m.

Saturn Vue and Equinox along with a few small Toyotas are known for this ability.

What I want to know is how to get the dual pinion variety, or at least the 'motor on the rack' variety. I don't know which vehicles came that way.

GameboyRMH
GameboyRMH MegaDork
7/28/17 8:11 a.m.
tuna55 wrote: Saturn Vue and Equinox along with a few small Toyotas are known for this ability. What I want to know is how to get the dual pinion variety, or at least the 'motor on the rack' variety. I don't know which vehicles came that way.

If you mean cars with a linear electric motor built into the steering rack, these are very rare and are now out of production, since the OEMs have found ways to get good steering feel out of the column-drive units. The Toyota Yaris once came with this kind of rack, it's a bolt-on swap into AE86s, but only early years had simple enough control systems to work without electronic mods.

collinskl1
collinskl1 Reader
7/28/17 8:17 a.m.

Dual pinion systems aren't as common as the rack based systems that are driven by belts and ball screws. The larger vehicles use these as the column drive units can't provide enough output.

There are many many newer vehicles with systems like this, but the packaging of a retrofit will prove difficult. Most of the race applications like ours would be easier with the column mounted systems.

The control module is looking for various signals from the car, and the "box" that you buy fakes these for the motor to work. Ignition, vehicle speed, etc.

tuna55
tuna55 MegaDork
7/28/17 8:27 a.m.

I know I saw some pictures of some trucks with the motor on the rack but I cannot recall which nor do I know how easy they are to fake

Ian F
Ian F MegaDork
7/28/17 9:09 a.m.

The S2000 has a rack with an integrated motor. Used ones are surprisingly reasonable on eBay. Not sure about the controller to make it work in a different car, though (or if one is even required).

Dbussey1
Dbussey1 Reader
7/28/17 9:12 a.m.

When I was looking at it for my Falcon, the Saturn Vue was the simple, cheap donor. Should be able to easily source in the junkyard

Keith Tanner
Keith Tanner MegaDork
7/28/17 9:16 a.m.

Current Miata has the motor on the rack. Keep in mind that it bulks up the rack considerably. You can control it with CAN signals.

Craigorypeck
Craigorypeck New Reader
7/28/17 9:25 a.m.

Sorry should have stipulated I'm after a column unit. I'm gonna run the power rack dry. It has one less turn lock to lock which I think is a better option for EPS as assisting a manual rack can be very very light in feeling I will have a look at the suggestions above. Many thanks.

Ian F
Ian F MegaDork
7/28/17 9:37 a.m.

In reply to Craigorypeck:

I understand it's not a good idea to do that for a couple of reasons. The fluid usually lubricates the mechanism and if you plug the ports it usually "hydro-locks" the internal passages. Fill it with fluid and then loop the supply return ports together.

chaparral
chaparral Dork
7/28/17 9:45 a.m.

The best steering feedback I've gotten from a power-steering system is from the new GM Alpha low-tension-synchronous-belt system. I'm not sure what inputs it needs.

Another alternative to consider is Armstrong steering. Weld the control valve in the pinion assembly, drain and grease the rack, and seal off the ports for the lines. Unless you're parallel parking or doing 3-point turns several times per day it won't take long to get used to.

Craigorypeck
Craigorypeck New Reader
7/28/17 11:09 a.m.

In reply to Ian F:

The rack has two fluids.. the low pressure lubricant can be left as is and high pressure cylinder can have some light grease put in and use dust vent caps on the in and out?

Ian F
Ian F MegaDork
7/28/17 12:05 p.m.

In reply to Craigorypeck:

Might depend on the rack. I'd probably still link the two ports no matter what just to make sure any air pressure that gets created during operation gets equalized.

MulletTruck
MulletTruck Reader
7/28/17 6:14 p.m.

I have a Saturn Vue with the 3rd party control module for my truck but I think the better option is the 2009ish Prius is better, When you run the 3 wires it has the perfect feel being in fail safe mode and no 3rd party module is needed.

Craigorypeck
Craigorypeck New Reader
7/28/17 9:02 p.m.
MulletTruck wrote: I have a Saturn Vue with the 3rd party control module for my truck but I think the better option is the 2009ish Prius is better, When you run the 3 wires it has the perfect feel being in fail safe mode and no 3rd party module is needed.

But the vue unit worked nicely? Can it be linked to some sort of speed sensor to adjust assistance?

Craigorypeck
Craigorypeck New Reader
8/5/17 10:55 a.m.

I picked up a complete unit from a Nissan versa.

They charged me 39 Canuckbucks at pick n pull.

Its quite large and I'll have trouble getting it under the dash. I may however be able mount it to the engine side of the bulkhead. This thing doesn't look to weather proof though.

Knurled
Knurled MegaDork
8/5/17 12:49 p.m.
Craigorypeck wrote: What modern car is a good donor for electric steering? The rebuilt power rack in my car won't seal as the ram was so pitted from rust. A replacement rack from Germany is over a grand delivered to me in Canada. Back in the UK the Vauxhall corsa was the car that everyone was nicking the E-steering from. Is there a similar go to for components here in North America? Plus I wanna get rid of the PS pump too. Thanks

Near as I can tell, the Corsa column is the same internals as what we got in the Cobalt and Malibu.

Saturn VUE also got a power column late in life (doing timing belts on the Honda V6 is so much easier when there's no power steering pump/hoses in your way!!) and I would guess that, given that it's a truck, its column got a beefier motor unit

Knurled
Knurled MegaDork
8/5/17 12:51 p.m.
tuna55 wrote: Saturn Vue and Equinox along with a few small Toyotas are known for this ability. What I want to know is how to get the dual pinion variety, or at least the 'motor on the rack' variety. I don't know which vehicles came that way.

Why would you WANT that? That's the bad kind of electric power, with the steering feel of recirc-ball.

This seems to be the way Ford does it. And apropos of above comments, it does bulk the rack considerably, in bad ways. Ford thoughtfully put the motor guts where the pinion would be on a RHD car (and, presumably, vice-versa) but it still takes up a lot of space. I replaced the rack on a Fusion last week due to some interesting faults, and it was not a fun process.

Knurled
Knurled MegaDork
8/5/17 12:58 p.m.
Ian F wrote: In reply to Craigorypeck: I understand it's not a good idea to do that for a couple of reasons. The fluid usually lubricates the mechanism and if you plug the ports it usually "hydro-locks" the internal passages. Fill it with fluid and then loop the supply return ports together.

Don't fill it with fluid. Pump it dry, loop the ram lines together, done.

I find it humorous. On rx7club, people with FDs say you have to take the quill valve assembly apart and weld it up or the world will end, or something. I figure this is because FD owners are weenies. When I converted my FB to FC front suspension in 2010 (same rack design as FD and Miata), I depowered the rack as I describe. No disassembly, no welding, other than cutting the power steering pump lines off flush and welding the nuts shut. A small section of vacuum hose connects the two ram lines together. I have driven the car this way for something like 70-80,000 miles, and have rallycrossed it this way quite regularly on some of the nation's roughest courses since day one. Guess what? The rack is still fine, the quill didn't break, there isn't any play in the steering.

This is known as reality getting in the way of theory.

BrokenYugo
BrokenYugo MegaDork
8/5/17 3:04 p.m.

In reply to Knurled:

I really don't get the whole "weld the valve thing" either, it's just a sloppy spline fitment, you could probably squirt some epoxy in there during assembly and get the same effect without the risks of welding on a mission critical mystery steel shaft.

GameboyRMH
GameboyRMH MegaDork
8/5/17 6:19 p.m.
BrokenYugo wrote: In reply to Knurled: I really don't get the whole "weld the valve thing" either, it's just a sloppy spline fitment, you could probably squirt some epoxy in there during assembly and get the same effect without the risks of welding on a mission critical mystery steel shaft.

Yeah epoxy's not a bad idea. The reason for solidifying it is to remove the small amount of play that's necessary for the valve to function, when you no longer have any use for the valve.

Mind you, EPS systems have a load cell in them, which is basically the electronic equivalent of the flexible shaft valve in a traditional power steering system (it also uses flex to measure the force applied at the steering wheel, which is used to control power assist actuation). So if you don't solidify the hydraulic valve when you convert a hydraulic rack to EPS, you'll have two flex-based power steering control systems in your steering column when you're only actually using one.

Craigorypeck
Craigorypeck New Reader
8/5/17 10:22 p.m.

I replaced the seals in the power rack so i had it completely disassembled and as far as I could see the steering pinion was solid the whole way down from the column to the rack gear. It does have a loose collar with holes in it.... which I assumed was the valve. It's a burman rack. So I don't think I would need to lock anything.??

I found a pic..

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