electric power assist steering

[David Morgan]

Has anyone tried adapting parts from a Subaru brz or scion fs-r? looks very similar to the kits available and can be bought very cheap used. My thoughts are I might try this plus use the brain box which would work off a vss so that the assist is related to speed and not have to be adjusted on the fly like the kit I looked at .I took a scion fr-s for a test drive just to see how it steered. I liked it! 

[socorob]

Ebay search for electric power steering controller. You can get a box from Europe that works with GM stuff for around $65. They've been doing it over there using opel stuff (euro gm) for a while now. The EPS setup they use there must be the same as here as the box is supposed to work with GM stuff available here. The boxes come with a knob that lets you adjust how much assist you like. The hard part would be mating the columns.

[yhlz]

Pros and cons and why would it be worth it?

[socorob]

There is already someone who makes a kit for the Z anyway. You send them your steering column back as a core when you're done. It ain't cheap though but it's all figured out.

[texis30O]

Who does this?

[socorob]

http://zpowersteering.com/

[seattlejester]

Pros: you get power steering. Less steering effort, more comfort. Wheel doesn't fight you going over bumps are small road imperfections.

 

Cons: there may be a delay in steering input, very small, but noticeable at highway speeds. Cost. Typical response, but it can feel like you are detached from what the wheels are actually doing. In the unlikely situation that it fails, the steering should revert back to manual, this can be jarring if you aren't expecting, or happens mid turn.

[socorob]

If its set to a low amount of assist it shouldn't mess with feedback too much. I guess that would be the beauty of the adjustable knob. Parking turn it up, track days turn it off. I think the motor is geared to the solid shaft, so if it goes out you should be back to as it was before you put it on instantly. http://www.autospeed.com/cms/article.html?&A=111532

This site has lots of good articles on all kinds of car related things.

[seattlejester]

Yea I just saw the adjustability with the assist level, that's a neat feature.

[Tony D]

Anything that works with a VSS will not have any assist at highway speeds, This is the way the Dutch unit works, and with any that hook to a VSS. The rotary pot adjustment of the assist simply puts a manual input to the VSS Input to the brain box. No reason for that, when you have a Nissan Tranny since the VSS off 90's models backfit easily enough. Or, like any number of old-school aftermarket cruise control, you slap some hall magnets on your driveshaft and set up your own VSS.

 

This is not as complex to make work properly as most would believe. I'm surprised they don't offer the flying hall solution instead of that knob in the first place. Makes it speed-sensitive power steering right off the bat.

[seattlejester]

^Very interesting, so the nissan electronic steering units turn off at highway speeds? I just remember that I felt like every correction would take a second and be amplified on the highway, almost like it was twitchy in the ford focus st I was driving. 

[Tony D]

That's not what I said.

I said the assist is variable, and at highway speeds, it's a direct connection link with no assist.

 

"Twitchy Steering" i don't know, I do know alignment, quill diameter, bushings, etc all play a part in road feedback. If you look how they work, you see the direct line to the rack and pinion. 

When steering assist goes out at highway speeds the 'heavy' wheel you feel these days is simply the same effort it used to take before the power steering came into being.

 

Remember those 15" steering wheels in a Corvair.... no need for power steering, you just made up for it with quick hands.

[seattlejester]

Sorry misworded, I meant reduction of the power steering assist at highway speeds. 

 

I am going to chock up my feeling with having just been around hydraulic and manual steering cars my whole life. Just felt foreign to me. I would adore it at parking lot/autocross speeds, but I would probably turn it down on the freeway.

[David Morgan]

So I recieved my brz steering column and brain box. The steering column is also telescopic. After looking at this and how it would mount up I have decided to just use the entire Subaru steering column. Now I want to try to hook a vss to my front wheels so I do not loose my assist at low speeds if my back wheels are spinning. This may be a problem since I have a 388 and a t-56.

[David Morgan]

I bought my column in pieces because when I looked for a complete one the prices were high. I now have all the pieces from steering wheel to the coupling in the engine bay. I bought the steering wheel as a temporary use item. The aftermarket makes an adaptor for aftermarket wheels. Momo plus others. At the moment there is a complete one on ebay for $ 339.00 with out the brain box. I have roughly $ 310.00 in all my pieces including the brain box. Here is what I have figured out. Mounting will be easy. A plate with two holes drilled in it as an adaptor to the stock mounting location. The stock Datsun headlight switch will bolt on because at that point the columns they are the same diameter. I will try this directly. Someone going for a stock look would like this. I am actually going to use the Subaru switches though.For a more modern look. I am also going to use the Subaru ignition switch. Yes I will have to make a wire harness but the car is getting rewired anyway. After doing some research I may buy another switch with related matching pieces to make some other modern features available. Cost wise probably cheaper to go aftermarket though. I am reading about vss sensors. At the moment my car has two available. One in the T56 and one in the r230 differential housing. Not sure if either would be compatible with or even if the Subaru brain box would recognize. May be able to adapt Subaru vss sensor by drilling tapping or however but I know the gearing could not be the same but maybe close enough. Slower speed will provide more assist, faster none. I would prefer a front wheel set up. I really do not like the idea of having to adjust on the fly so an adjustable box will be my last option. May try it temporarily to get a feel for the assist, but it would be a pain considering I want to autocross this car and I really want this to be automatic and hands free. Does anyone have any ideas for a front wheel vss sensor?

Edited April 5, 2014 by David Morgan

[David Morgan]

I found a solution to convert one of my existing vss to one that the Subaru brain box will recognize. VSS Pro from DCCD Pro.com. With a little work I think this will work and be way cheaper than the $ 2,000 kits on the market and be more user friendly.

[Tony D]

Old Cruise Control Systems used magnets glued to the driveshaft and a hall sensor. You can glue them on almost anything you want as long as you can mount a sensor. The VSS is really not that touchy, if you can determine the pulse rate up to around 35mph, and fit your magnets accordingly, it will work. Frankly if you have electronics background you could use ONE magnet, and then make a signal multiplier to output the required waveform accordingly.

 

Really if you change to an Electronic speedo, the VSS for it will splice a signal just fine. Tire spin brings up a strange quandary as I don't recall if you loose power steering assist...I mean, I can see how you should as the VSS says you are going 70 when you're standing still... But doing brodies really isn't where power steering excels. It's in parking lot maneuvers with wide tires and big steering angles at very low speeds. 

 

Most cars, no matter how wide the tires, going forward at speed really doesn't need a lot of assist. The faster you go the lower your steering angles need to be to keep a stable vehicle.

 

I'm going to have to go do brodies in the Suzuki and see what the e-steering does. If I can get it do to smoking, rolling, boiling brodies in the first place...

[David Morgan]

Tony D.   How did the Suzuki hold up? After you mentioned about making my own vss setup I did some research and this looks very doable.  The Datsun switches do bolt on and with a small hole cut in the shaft cover and a cam welded on to cancel the turn signal it would work, but like I said I will be using the Subaru switches which to me makes more sense. I will have to add a dimmer switch for the lights to the dash but I already got the one from the Subaru as well which also has a hatch release button beside it. Another added bonus, just keep giving myself more work! LOL! Another benefit I see is that where the shaft comes through the firewall I can move this to the right slightly because of the design of the steering column, it has another u joint. This will give me more clearance for my headers. I am going to either make a plate to match the Subaru boot or just cut that section from a donor car to make for a clean install. The end of the column that will come through the firewall is also telescopic which will make it easy to adapt to the Datsun linkage.

[Tony D]

The Suzuki is in a Suzuki.

 

 

I have an LHD Converted 1990 Suzuki Every 660Turbo (nee Daewoo Damas now I suppose)

 

I have to up the boost a bit to break the tires free to do the brodies... though the Speed Sensor MAY be on a pulser wheel inside the front differential (it's Pushbutton 4WD)

 

I will NOT be boiling all four tires...not with this engine! No matter what boost I'm running.

 

Now, taking a Sunny Pulsar GTi-R driveline and bolting it underneath... Heeeeeey.... We're on to something there!

[David Morgan]

At some point i will post some pictures but the column is mounted. It was rather easy. Waiting on a section of firewall from a BRZ then i will be working on the electrical part of this swap.