4 Wheel Steering Discussion (Page 2/2)
MichiganReefer NOV 18, 04:36 PM
I think something I will also consider with a switchable steering button is to have an override/mode that defaults to 0 rear steer angle. Does anyone with a 84-87 have a decently clear picture of the gap between the engine and the cradle that the steering rack could fit? I might need to buy an older cradle to use as a bench system.
pmbrunelle NOV 18, 06:51 PM
The engine wouldn't come close to the rack.

Assuming the muffler is removed, the trunk would be the most likely source of interference for a rack, followed by the automatic transaxle. The standard transaxle is much more compact (i.e. non-existent) towards the rear.
Frenchrafe NOV 19, 03:07 AM
This sounds like a good idea. A bit out of my capabilities for the electronic control/piloting, but hey!
I would like to point out that the Fiero has quite a short wheelbase and that handling is quite good already. Ask my track friends who drive GT86/BRZ which have longer wheelbases!
The only ones who out perform me (on the bends) are the Lotus Exige drivers!

Regards,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. - The fastest Fiero in France!
https://youtu.be/c4Cu7_2OgYc
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

pmbrunelle NOV 22, 07:30 PM

quote
Originally posted by Frenchrafe:
I would like to point out that the Fiero has quite a short wheelbase and that handling is quite good already.



I think that OP simply wants to explore, not that there is a specific problem needing fixing with rear wheel steering.

I happened to be looking at Texense products today, and I had a flash that a sliding potentiometer like this would be easy to add to the 84-87 Fiero rack:
https://www.sens4pro.com/en...ers-4/112-rsl-1.html

As Rodney Dickman sells special hardware to add a second steering damper to the rack, I think that special hardware could be used to mount a potentiometer on top of the steering damper.

A small magnet mounted to the end of the pinion (can it be made accessible easily?) could be used with an end-of-shaft magnetic sensor for some limited (modulo 1 steering wheel turn) redundancy, but I think it would be enough to catch the likely failures, by comparison with the potentiometer's reading.

It is ideal for redundant systems to use completely different technologies. In this case, a magnetic field could make the magnetic sensor read incorrectly, but not the potentiometer. A broken mounting stud would make the potentiometer read wrong, but not the end-of-pinion magnetic sensor.

Two of the same sensor are likely to share the same design flaws, or to be influenced the same by some external environmental factor... so even though the measurement is wrong, both measurements will be equally wrong, no problem will be detected, and the redundancy will have been for nothing.