Electric power steering on a Beta

[squiglyzigly]

Heavy steering is the only thing I don’t love about my Berlina. It’s a wonderful drive until you slow down or heaven forbid, wish to manoeuvre into a parking space.
Since putting the Berlina on the road tin 2020 it became apparent that using it as a daily runner in London was going to require me to get down the gym or come up with a way for the car to help me out.
What with gyms being closed due to lockdown (result) I decided to see if it was doable to fit some kind of electric power steering. Now from the off I should declare where I sit with modern car electric steering debate. I HATE THEM. But there are not many options are there? Hydraulic power steering on a Berlina. High parts cost and lots and lots of work put me off of this.
So I done some internet reading and made a hasty eBay purchase or two based on the theory of “well if it can’t be done or I don’t like it then it goes in the bin and £100 worth of spares won’t be the most stupid thing I’ve tried”.
So this is where it began. . . .

[squiglyzigly]

The electric column is from a 2008 Toyota Prius. My reasoning was that Uber Prius drivers clock up starship Millage and every Uber driver I speak too has never had a problem with the steering. Then they are cheap and plentiful in the breakers yards. Judging by the driving standard of the average Uber driver I get, I think I know why the breakers yards are full of smashed Prius’s (what’s the plural for Prius).

And most importantly, when used with its matching steering control module, its a 3 wire installation! ! !
That sold it to me on what is essentially an experiment to pass some furlough time.
When you connect the control module to permanent live, earth and ignition live, the steering module looks for the main body computer which is of course hundreds of miles away and then after about 5 seconds it simply powers up in “safe mode”. This is a mid ground assistance level.

So the picture is the starting point of stripping a beta upper column and opening up the Prius column to find it is very nicely made with two half shafts in the upper column. Very useful I thought.

[squiglyzigly]

Onto the precision job of dummying the column under the dash. Carried out with tie wraps and a cardboard tube. What can go wrong? It confirmed that there is very little space even after cutting a gusset into the pedal box to get it up high enough to retain the original rake of the old unit and also to not get in the way of your feet. It then becomes apparent that due to the extra length of the Prius column due to the bulk of the motor the lower link shaft with the two UJ’s will now go straight through the clutch pedal.

[squiglyzigly]

So the clutch pedal gets a swan neck and onto cutting the mounting brackets off of a spare column to weld onto the new unit.

[squiglyzigly]

Brackets transferred over so time to bolt it up under the dash and move onto the lower steering shaft to see if this project is a waste of time or wether it can fit.

[squiglyzigly]

Lower steering shaft was a case of using the nicely made Toyota shaft upper plus UJ and welding the beta lower UJ to the nice sliding shaft that came as part of the Toyota piece. This was very useful in my view because the shortened lower shaft was now going to be running at more of an angle than before and I had concerns of the shaft pushing and pulling a little as the UJ rotated. So the sliding spline shaft design (collapsible crash design?) would happily take up any slack.

[squiglyzigly]

Then to make the Toyota upper shaft into a Beta fitment. Transferring the steering lock barrel and welding the Beta steering wheel shaft ‘into’ the Toyota shaft. Lady Luck made this easy to weld straight and true. The cut off piece of beta shaft was an interference fit into the cut down Toyota shaft so it welded up without any heat distortion trying to make it a banana. Then a 1mm thick sleeve and a circlip groove (cut with a dremel and finished with needle file) to fit the original bearing meant the power steering assembly was now Beta fit.

[squiglyzigly]

Finished upper half shaft. Beta steering lock barrel and upper shaft grafted to Prius upper half shaft and bearing.

[squiglyzigly]

New power column ready to fit. Almost looks normal.

[squiglyzigly]

Then to the simple job of 3 wires and a module. With the original factory brackets trimmed off, the compact box found a new home in the corner of the dashboard.

[squiglyzigly]

Wiring done, column bolted in, just put the clocks back and time for a test drive 

[WestonE]

Impressive work and creativity. I am looking forward to hearing how the test drive goes!

Eric

[peteracs]

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

[betabuoy]

Hi Ian

This is edge-of-the-seat stuff and we certainly need to keep you in furlow to see it through! Terrific work and hugely interesting.

Chris

[frankxhv773t]

My daughter's Yaris has Toyota electric power steering and I hated it compared to the hydraulic power steering on a previous Yaris my wife had. I felt there was a lack of connection between steering inputs and response.  I'm inured to it now so you do get used to it. That said, your installation is a masterful piece of work so I'll be interested to see how it turns out. As a solution to heavy steering for town driving it seems an elegant solution.

[squiglyzigly]

Good morning chaps,
Thanks for your interest and kind words. I hope this helps some of you decide if it’s worth the effort and I’m always happy to share what I’ve learnt.

Well it’s had its shakedown and in short, it’s staying.
It’s not without fault but then it never could be. For me it was always going to be an experiment to see if it could be done and if the positives outweigh the negatives.
I’ll try to give my first impressions before I forget them as I think it’s always important to be able to refer back to them at a later date as more thoughts and feelings come to light. And I’m happy to share this project for a long as I don’t bore everyone to death.

This morning was a nice bright chilly start and the roads are a mix of dryish but slippery winter roads which is a nervous way to start a test which will inevitably end up with me pushing my luck. First up, reversing out of the garage and 3 point turn to get out of the cul-du-sac which is a bit busy with strewn Alfa’s and a VX coupe (guilty m’lud). The Berlina passed the obstacle course with consumate ease winding from lock to lock and enabling me to control the steering with an air of grandeur in front of the neighbours instead of the usual red face, tugging at the wheel and lifting my backside off of the seat. First notable negative as you pull away is very little or no self centering of the wheel. So that’s the first question ‘‘can that be improved?’
Then along the wiggly drive to the main road and I’m liking my new found steering muscles. It’s a big positive. The strange thing to note immediately is that this doesn’t feel modern and I think this may be due to the fact that it is still running a Berlina 3.8 turns lock to lock rack. Second question ‘time for a coupe rack and possibly a smaller wooden Nardi steering wheel to quicken it up?’
Then off onto the main road and trundling along at 30mph and the car just feels 90% the same. The steering inputs are the same and the gentle change in direction is the same, it just feels like someone has maybe put an updated steering damper on the rack. Not in a heavy way because you now have assistance but its a kind of plush feel. Positive not negative.

Then out onto the A21 and we’re up to 40-50mph and I wind my senses up incase something unusual happens and I need to react sharpish. I’ve put a switch on the dashboard so that I can power the unit down immediately if things get a bit lively. But there’s not much to add. To answer Peters question ‘this has no variable assistance provision’ so I’m worried the faster I go the less suitable the modification will be. But no, it’s working fine and still steers  90% the car it was. This must be to do with the torque sensors in the shaft not being pulled on by the driver. Little input request equals little assistance given. I guess???

So the bravado is rising and the dual carriageway is up ahead with national speed limits to explore.
Road opens up and it’s time to let the tweaked 2.0 trot on. The dual carriageway is uphill, gently sweeping into a downhill with a large roundabout to finish. 90 plus and still it’s not scaring me. No lightness, no nervousness, nothing in fact it feels near standard. So the damp roundabout is going to get full tilt midway round and back towards home. Winding the speed up on the big empty roundabout and with the door handles almost scraping the tarmac she gently starts to slide. Just like a standard Beta you steer, you change throttle and it does what a Beta does. But there is no feedback forced from the tarmac to the steering wheel. More questions in my head. ‘Would a dry surface change this?, would a faster ratio rack change this? Is the Berlina on its standard high rise suspension and fluffy 65 profile toyo tires ever going to give much feedback? And would a lowered stiffened coupe be better?’

The final test on the way home was planting it in 2nd gear coming off a roundabout and letting the wheels spin up in turn. Easy to control, really easy, the power steering just lets you decide which direction to choose. No torque steer. Yes a bit PlayStation but it’s good to look relaxed in a 40 year old Berlina.

Hope your all still awake

Ian

[Nigel]

Really impressive Ian. This mod will become a go-to for many folk.

I wonder if the Coupe/HPE version has less vertical space ,and whether the pedal box etc
is in the same spot relative to the column? Questions for another day perhaps.

Compliments to you!

Nigel

[smithymc]

Fantastic work- in awe.

[WestonE]

Hi Ian  A new role in motoring writing beckons!

More significantly this is a modification with a ready market for you to earn some much needed money. Especially if you can get it to neatly fit S2FL Coupes and Spiders which probably make up the bulk of cars left on the road wanting PS. It would be great to see the effect of using a smaller steering wheel and then a Coupe rack with the large factory wheel and the far nicer Italian aftermarket smaller items. Of course playing with wider tires will also give a feel for what works well. Have you kept standard Camber and Caster?  NB adding caster could fix your self centering question mark and potentially improve turn in.

Modern cars have a lot of caster compared to our cars and rally cars have a huge amount.

I installed OE Hydraulic PS to my Beta Spider build knowing I would add 1.5 degrees Negative Camber, wider tires (195) and a Momo Competition smaller steering wheel. This was based on my experience from doing this on my previous Beta Spider and getting nicely weighted steering over the speed range.

In fact my old car in light blue with Thema wheels and PS added by me is on the 2021 Forum banner to the right of the date!

Keep up the good work and think about offering this to other owners. I believe you have a ready market.

Eric       

[squiglyzigly]

I feel I should apologise for the graphic equaliser hanging from the steering motor on a tie wrap but it and the original drivers side under dash speaker were made homeless in the making of this project. So a sound system rethink is next.
As a test run it was a short 20 miles or so and didn’t include the kind of lovely B roads which most of you more northerly chaps enjoy but lockdown rules suggest I shouldn’t be out for steering checks.

Nigel, I think the pedal box/adjustable steering column layout looks incredibly similar between the berlina and coupe/spider/HPE version. I’d bet the same.  I did notice the spare column I cut about (a coupe/HPE version) was about 20mm longer. I chose to follow the dimensions of the coupe column as I feel the steering wheel is way to far forward for me to the point of banging your fingers on the windscreen every time you thank an oncoming courteous  driver for letting you through. This meant modifying some coupe column plastics to suit.
So I think mounting the motor assembly should be much the same and the module can easily have wires extended to wherever space permits.

Eric, thanks for you compliments.
Yes the car is on completely rebuilt but standard suspension. Only notable change being poly wishbone bushes.
I’m in complete agreement with the camber caster principal. Especially the caster as this is the big self-centering govenor. As front wheel drive cars naturally pull themselves straight under acceleration they run less castor, by contrast RWD cars do not. So they run big castor. And the modern fwd cars run more because they can with the PS and the advantages it brings. The Beta has very little and with the power steering available it surely is a useful avenue to explore. I probably won’t try this on the saloon as I want to keep it looking as original as I can. Special top mounts and custom wishbones really aren’t for this car. That’s what my VX is for.
But a coupe/HPE rack and smaller steering wheel are very likely although I somehow do not have a manual rack laying around. Will have to source one if anyone has one laying around.

Once I get out and about I will see how it drives on motorways and on twisty B roads.

Update to follow.

Ian