Electric power steering on a Beta

[frankxhv773t]

What you say about the change in feel is a good description of how I experienced the difference between hydraulic and electric in the Yaris. It'll be interesting to see what a difference further modifications to the suspension etc makes to the project. I'll not be spending any time trying to copy your findings on my daughter's Yaris but if that has to be scrapped in the future I might just be saving the steering column for my Spider.

[betabuoy]

Hi Ian
I do have a spare manual rack lying around. If you msg me with your address, I’ll send it down to you to play with.
Chris

[squiglyzigly]

Thanks for your offer Chris,
Let me have a dig around in the loft first. I must have one after the amount of cars I’ve stripped.
But if I fail to find one I’ll take it thanks.

All the best
Ian

[HFStuart]

Great piece Ian. I'm not sure it would fit a pre f/l car but as Eric says it could well do in the F/L versions.

On caster, Hillman Imps were very light at the front (obviously) and ran 8-11 deg castor to improve feel and centering.

[squiglyzigly]

Great piece Ian. I'm not sure it would fit a pre f/l car but as Eric says it could well do in the F/L versions.

On caster, Hillman Imps were very light at the front (obviously) and ran 8-11 deg castor to improve feel and centering.

I’ve never owned a pre f/l, so I’m not familiar with the shape of the under dashboard layout.
I think the main snag point is the line behind the steering column pivot point. If that pivot point is roughly inline with the edge of the lower lip of the dashboard then I expect it will be doable.
That point is where the motor and gear housing bulk needs to go.

When I get time I’ll have a look under the dash of the VX to see if post f/l cars look doable just in case someone feels the urge to give it a try.

Ian

[squiglyzigly]

Hi

Yep, very impressed with the end fit, I also hope the end result is a good one. This is going to be an ongoing need I think. I was surprised you managed to fit that large motor which sticks out of column hidden away so well!

Is there any adjustment to sensitivity on this system?

Peter

Peter, I’ve done a little nosing around and further down the line I will try a few experiments to see if adjustability is a possibility. I can’t find any information to suggest anyone has done it but I have a few suspicions that it maybe possible.
There is an input on pin 5 of the Prius steering module that is for speed input. I intend to play with that at some point in the future. I also suspect a module from a Yaris may work on my Prius adapted column. That has a similar feature and I believe some people have played with a potentiometer type adjustment through an eBay module. Although I’m not into fiddling with knobs whilst I’m driving I think it might be possible to give a speed input to it via a Brantz speedo cable interface. These are used for classic rally computers etc.
So maybe, just maybe there will be future upgrades to this project.

Ian

[peteracs]

Hi

That is interesting. I did see on one supplier of new kit that there was an option for speed input and that would make total sense if you already have a controller in place.

What make is the motor on the one you have used?

Peter

[squiglyzigly]

I’m not completely sure how to answer that.
The motor is Denso as is the control module but the torque sensor is made by JTEKT.
But as a complete entity I believe they ‘may’ be referred to as Koyo products.
I gather it was a joint collaboration between ‘Koyo Seiko’, Denso and Toyota to develop these steering controls so I’m not sure what you would call them singularly.

These Koyo units appear to be fitted to a good number of different manufacturers.

[chrisc]

Fantastic implementation, and a nice usability upgrade. I actually prefer heavier steering for some reason, my old alfasud sprint was enormously heavy - it was undoubtedly a pain sometimes, but also in my memory it's one of the fondest things I recall about the car.

[squiglyzigly]

The electric steering project has moved on a little.
As mentioned in the first test drive the lack of self centering out of junctions and roundabouts felt a little odd and out of character. So I decided to carry on exploring in the hope of a more complete package. I decided to explore the Castor angles as previously mentioned but of course there is no built in adjustability. My chosen route was two fold as I was aiming to double the standard beta castor angle. My car measured up at 1.3 degrees n/s and 1.4 degrees o/s. (Factory spec)
With a couple of spare wishbones to hand it was time to experiment.
My plan was to cut and shut the leading edge of the wishbone where the lower ball joint bolts in and then weld up the bolts holes and ball joint hole and re-drill them all 10mm further forwards. Then slot the top suspension turrets 5mm rearward and slide the top mounts back.
To my joy I got 2.4 degrees Castor n/s and 2.5 degrees o/s.
Whilst I was down there I removed the factory positive camber and dialled in 1/2 degree of negative camber.

The third photo with the black and silver wishbone is modified next to a standard one. From under the car you’d do well to spot the 10mm modification.

Road test time.

[WestonE]

Hi Ian great to see more pioneering development. This is how our cars can become better in ways purists would struggle to notice. This could be built into new stronger wishbones is your testing confirms the improvements I am expecting to hear.

I have used multi hole top mounts with slides to have the scope to make adjustments like these, but because they are solid I expect a harsher ride and I am considering a firm rubber ring at the interface if I can work out how to get one made!

Looking forward to the road test results.

I wish work was not manic so I could make some progress.

Cheers

Eric

[squiglyzigly]

Hi Eric,
Yes I think it’s the way to go to keep the original look and feel when originality is a priority.
Slotting the original top mounts 5mm was easy to disguise with a slightly larger washer.

The first 100 meters with the changes and it’s obvious the castor angle increase does its job. As soon as I start to negotiate the S-bends out of the drive to get to the main road the steering is centring up of its own free will and I’m grinning like a child. It works.  But before I go any further I want to know what it feels like without the steering damper. So a quick pit-stop and damper is relaxing on the bench.
Now we’re off to B&Q for some emergency supplies and a Long way home via the A20/M25/A21 to get a full understanding of this project.
I find it difficult to quantify all of the feelings and observations but the words that keep coming to mind are that this is how it should be. Yes the steering is light’ish all of the time with minimal feedback, but then the original steering with its saloon spec 3.8 turns lock to lock was like that until the speed dropped below 15mph. And yes it feels a little different on the move, but that’s not a criticism.
Every car feels different right? I believe every beta feels different because they were all made like that for one reason or another, and they are all maintained differently with different wheels and tyres. Even a small change to front suspension toe makes a beta drive differently. Or tyre pressures.
So now I’ve made it feel different again. And I’ve decided I like it and wouldn’t go back. It’s now easy to drive in town and it’s as stable on the motorway as it was before. The faster you go the easier it seems to be to hold a line. Castor.
When you pull out of a side road the steering straightens up in a way that lets you slip the steering wheel through your hand but tighten your grip just a little and it stops spinning. When your navigating a large roundabout it’s just the same. It straightens up but is easy to stop and turn to the other lock and take your turn.

In essence the e-steering project is all but finished. The cherry on top will be a 3.5 turns coupe/spider rack which is pencilled in for this year when I drop the drivetrain assembly for a gearbox overhaul. The faster rack will undoubtedly be slightly heavier and slightly quicker. Perfect I expect.

Today, Sunday, was my seventh straight day at work and I needed a smile. So I took the Berlina to work on the cold salt covered roads and grinned for 45 mins each way whilst listening to ‘80s greatest hits’ with one arm on the door panel. It’s an easy car to drive now.

[WestonE]

Inspiring and an opportunity for others to benefit. Few old car designs are so good that you can bring them bang up to date with relatively minor changes. If it was a Ford Escort you would be throwing most of the OE suspension away.

I am looking forward to hearing how the 3.5 turn rack works and if no damper is an issue longer term with sharp bumps and pot holes kicking the wheel? FYI the Monte and X19 do not have a steering damper.

Eric   

[peteracs]

Hi

Can I ask a simple question on the subject of castor.

I understand from reading that the larger the castor angle the more self centering, however does this also mean heavier steering, hence the current manual steering setup is a compromise on the two?

Peter

[mangocrazy]

Following all this with great interest. So basically it's a question of moving the ball joint mounting inwards by 10 mm? As for the suspension top mount, would something like this obviate the need to slot the top suspension turrets?

https://www.ebay.co.uk/itm/FITS-Lancia-Beta-ADJUSTABLE-TOP-MOUNT-1-pair-CMB4455-135mm-PCD/281762386123?

[peteracs]

Hi Graham

From what I understand it is moving the ball joint forwards by 10mm and the upper mount backwards to achieve an increase in the castor angle which is the angle viewed from the side of the effective upper and lower mount points of the hub and the vertical. See

https://en.wikipedia.org/wiki/Caster_angle

The larger the angle the more centering you get is how I read it.

Peter

[squiglyzigly]

Morning Eric,
I can already answer the question of torque and bump steer as I’ve deliberately asked for trouble during the drive to work on Sunday morning. It wasn’t exactly difficult to find a few pot holes!
Both aspects seem to be dampened/controlled by the e-column. You can tell the wheels are fighting with the road surface but it’s no drama in the driving seat.

I did notice during the work grafting the Beta and Prius columns into one, that there seemed to be some sort of steering damper effect within the gear/motor assembly. This primed me in advance to test both with and without the Beta damper fitted.
Also I did have to open up the gear housing as it was necessary to spin it 180 degrees to improve clearance under the dashboard due to the shape of the alloy casting. I couldn’t see anything inside that seemed designed to give what feels like a fluid damped movement. So I assume it’s simply the resistance of a large cog working against the worm drive of the motor.
Maybe it’s this built in design that controls the torque/bump steer or maybe it’s in the steering ecu. I really couldn’t suss it out.
But the outcome is that it drives better without the damper attached. The biggest improvement is in the straight ahead to near straight area. The damper limits the self centering a little as the castor effect works less when the wheels are near straight and conversely self centering is much greater on lock with extra castor.
So this e-column conversion makes the damper unnecessary.
I’m looking forward to the 3.5 rack but that won’t be for some months yet.

[squiglyzigly]

Hi

Can I ask a simple question on the subject of castor.

I understand from reading that the larger the castor angle the more self centering, however does this also mean heavier steering, hence the current manual steering setup is a compromise on the two?

Peter

Hi Peter,
In a word Yes.
If you increase the castor you will get heavier steering. Without power assistance you’re going to notice it. One nice performance bonus of more castor means you get increased negative camber on lock. Very handy for cornering and also you don’t have to run as much static camber. Again good because having the tyres square to the road gives maximum braking efficiency. On the Berlina with its high soft standard suspension, I expect the factory positive camber is to give a flat contact patch when the car dives under braking giving a square contact patch. This is because the wishbones push the wheel out under braking to remove the positive camber to something near zero degrees.
My knowledge on suspension design is basic so I don’t know for sure why older fwd cars run less Castor but I would hazard a guess that it’s a combination of reasons. Top of the list is most likely steering weight. 

[squiglyzigly]

Following all this with great interest. So basically it's a question of moving the ball joint mounting inwards by 10 mm? As for the suspension top mount, would something like this obviate the need to slot the top suspension turrets?

https://www.ebay.co.uk/itm/FITS-Lancia-Beta-ADJUSTABLE-TOP-MOUNT-1-pair-CMB4455-135mm-PCD/281762386123?

Hi Graham,
Yes those top mounts are designed to allow you to increase castor and or camber. I didn’t want to go down that path because a) it won’t look remotely original on the Berlina and b) the ride quality, noise and vibration is again something I didn’t want on the Berlina.
However horses for courses, I have got top mounts similar to these on the VX coupe. (Some group 2 escort mounts that I modified)

Also the ball joint position question is as Peter said. The ball joint moves to the front of the car.

Should I post a picture of the slotted top turret on the Berlina?

[WestonE]

Hi Graham

I am using that sort of multi - point adjustable top mount with a central bearing, but I went for the version that has a slide in the center so it can be fine adjusted when it comes to set up with 4 wheel alignment kit. I am nervous about whether I also need to put a hard rubber damper ring between the mount and the body shell to damp harshness. However with the excellent damping in the Gaz Gold coil overs I am using it might not be needed.

Eric