Electric power steering is installed

[Art Vandelay]

I spent more time and money than I intended, but my SVO with electric assist power steering is done and driving. I used the fox body kit from EPAS Performance, so I didn't have to engineer much of it. I am making a few extra column support brackets because I don't think the kit is adequate in this regard, and I also made a custom collapsible steering shaft in front of the firewall instead of using the shaft from the kit. First driving impression is good, even with a bad alignment. The steering rack itself is a Flaming River quick ratio manual rack. I can add more details if anyone is interested.



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[Mike S]

Cool! Does it have the separate modes like the late model Mustangs?

[Art Vandelay]

This kit is like most aftermarket kits, and has a knob to adjust the level of steering assist. Most people just settle on a middle ground position and leave it alone.

My next step is to modify this to give it speed-sensitive power assist. I have a Ford speed sensor and Arduino microcontroller on my test bench, and have a proof-of-concept for changing the assist level as speed goes up. The adjustment knob is just a 100kΩ potentiometer, and I have a digital potentiometer that I will splice in to replace it.

From here, I could add a switch to create different steering modes. I'm going to finish the base code while the car is in storage this winter, and see what makes the most sense after driving it more.

[rodster]

Would definitely like to hear more. Very interesting!

[Raven855]

Post some more pics if you could. I had been gathering info to do the conversion for quite awhile. Just haven’t done it yet.

[Art Vandelay]

One negative of this system that I didn't consider until mid-install is that this replaces the collapsible portion of the steering column. This is why I made the collapsible shaft down below, but I may address it further. There is limited space to do this. There may be enough joints, couplers, and my new collapsible shaft section to prevent the steering column from going through me in a bad crash. My collapsible section of my stock steering column had a lot of rotational play in it, which was leading to thunking noises and loose steering, so at least that is gone.

Here is a picture from early in the installation. The firewall plate is shown here. I didn't think to trace it for a template. The hole accepts a 3/4" steering shaft support bearing, like this one. The left side of the motor has a coupler welded to the end that accepts our 3/4" DD steering shaft just below the steering wheel. The right side of the motor has a splined end, and the kit comes with a coupler welded to a 3/4" DD shaft that goes through support bearing at the firewall.

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And here is my steering shaft. The top universal joint is 3/4" DD on the firewall end, and 1" DD on the lower side. I have a 1" DD tube from Borgeson that slides over a 3/4" DD shaft that came with my old Flaming River shaft kit. The lower universal joint is 3/4" DD on the top, and a splined end that fits a manual rack. I put a boot over the steering shaft, took a chance on this one and it was a perfect fit.

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EPAS Performance has great technical support and I have to give them credit for making a fox body kit, even though there is not too much specific to a fox body. This could definitely be done cheaper, especially if you know how to weld.