Turning power steering off and on?
 

I drove a 2008 Malibu and took the power steering motor out just because, and I actually quite liked the feel of it all the time. It was an auto and kind of a beater though so I want to do it more tastefully to my FR-S.

The idea I like best would be to install a switch (or even a variable resistor to adjust amount of assist) by the trunk button where it would be very simple to turn eps off and on for whatever driving conditions you were in or whoever was driving.

Is there a convenient wire that could be used to perform this function? I was thinking it could be the wire for the strain gauge sensor so that you could just interrupt the signal and the whole system could still be on, but just not doing anything because it thinks there is no steering force it needs to counteract. Not sure about the intricacies of the system, is that feasible?

Turning power steering off and on?
 

I would start by pulling the fuse. You will quickly find the FR-S is not a Malibu. The FR-S ratio is 13:1 vs 16.4:1 on the Malibu. With EPS disabled the FR-S is incredibly hard to turn even while rolling.

It’s the #46 fuse in the engine compartment. It’s 80A for a reason. It takes a ton of power to manhandle the tight steering rack.

I tried that on my BRZ. The steering is much heavier even at speed. Even mild curves require quite a bit of muscle to turn the wheel (and keep it turned). For me it detracted greatly from feeling the car, but it might be that after a while ones would get used to it. In addition, there was a strange feeling of looseness in the steering at certain points that isn't present when the power steering is active at all.

It might be that keeping the assist motor still connected adds additional resistance to turning the wheel, but I'm pretty sure the majority of the effort comes from the quick ratio rack and high caster angles (vs. non power assisted cars like the Elise of 4C - an Elise runs a 15.8 rack with under 4* caster, the 4C runs 15.7 rack and under 3* caster, vs. the Twins 13.1 rack and around 6-7* caster) as well as quite a bit of vehicle weight over the front wheels (due to the 55/45 weight distribution and the extra 300-800 lbs vs. the non power assisted mid engined 4C and Elise with a weight distribution of around 40/60).

No harm in pulling the fuse and having a go, though.

Thank you, very helpful info. I tried driving with the fuse out and, call me crazy, I loved it! I even thought it felt a little easier than the malibu, and this was on dry roads with sticky summer tires. Maybe because the malibu's weight distribution is much more front-heavy and is just heavier in general?

Anyway, that brings me back to my question, is there a more convenient wire I can put a switch on than the big main 80 amp cable?


EDIT: I found the wiring diagram here in the EPS section: https://www.ft86club.com/forums/showthread.php?t=43087
And here's a convenient thread with several diagrams and pinouts in one place: https://www.pro-touring.com/threads/...n-A-Body/page2

Looks like the torque sensor has four wires in connector z2, I'm assuming they are Voltage in, Ground, 1, and 2. Seems like the 1 and 2 wires may be the ones to look closer at, any information on what kind of signal they carry?
(pictures not my work, credit to linked thread)
https://www.pro-touring.com/attachme...5&d=1545455546
https://www.pro-touring.com/attachme...6&d=1545455614

I'd hate to arm wrestle this guy.

https://metro.co.uk/wp-content/uploa...size=480%2C360

If your arms ever get tired, try the Perrin steering rack lockdown. It feels like slightly heavier steering with more feedback.

- Andrew

I miss my 240Z street/track car, BAD. The manual steering was quite good on that car, but that is definitely one part I do NOT miss.

FT86 electric power steering is *quite* good, I rate it higher for responsiveness and feel than the 987.2 Cayman I owned for a year (which everybody raves about, but I didn't care for the on-center slowness and nonlinearity around 45-60 degrees steering wheel angle).

Do what you will, but you shouldn't automatically equate *heavier* steering with *better* steering feel...

I put solid mounts on the rack in my IS300 (1st gen) and man it made a big improvement to feedback. I didn’t realize there was anything like this for the Twins. Thanks for the heads up.

The Twins have multiple options - stiffer bushings, solid aluminum bushings, Perrin lockdowns and Cusco rack brace. I went with the cheapest stiffer bushings I could find (at under $20 shipped) as the other options are quite a bit more expensive. This thread was the main reason I saw no point in splurging for the more expensive solutions. Plus the Cusco rack brace doesn't look like it can do something useful (although there are some positive reviews around here for that).

Did you also delete Windows and install DOS?

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