EPAS - Electric PAS - anyone done it here?

Hi chaps,

Newly back into the world of Landies, I'm really surprised that I can't find anything on the net for a Corsa steering column swap out on an S3 to give power steering. A couple of in passing debates, but nothing substantive.
Has anyone actually done it? It doesn't look a particularly tricky problem so far as I can see - and if no-one's done it, why not? Am I missing something here?

If I can't find any substantial objections I shall be doing it and publishing the results here.

To that end, can someone assist? If anyone has an s3 steering column & box out of the car, please measure from the end of the steering wheel splines to the point where the shaft enters the steering box. Just for feasibility purposes - if I can contrive to keep the Corsa ignition key, steering lock & wheel, then so much the better.

Thanks all.

Just for info:-
http://www.super7thheaven.co.uk/blog/corsa-c-electric-power-steering-epas/

I haven't done it - yet, but I have a Punto column ready for mine (coil sprung, but the same problem). Probably much the same in principle.

Do take pictures and write a guide for the benefit of others.

boguing said:

I haven't done it - yet, but I have a Punto column ready for mine (coil sprung, but the same problem). Probably much the same in principle.

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Can you point me at any electrical tech. detail on the Punto column? It's also a candidate. Is it controlled in the same way as the Corsa do you know?

i was going to use the Corsa column, but ended up buying a bargain Punto in a rush after writing off my SIII. While I was buying a part for the Fiat on eBAy, I got chatting to the seller , punto_spares on eBay, who competes in some events with a 4wd he has built. That uses a Punto column, and he described using a system that your link describes (cheap box that isn't very good). I thought that I'd either improve on the box, or go down the route described in the article, but in the latter case with the aid of a software engineer that I know. Unfortunately for you, that's not even on the back burner until I find a house/workshop to buy, which is my current project.

As it happens, the Fiat died, so it became obvious that I should take the column out of it before scrapping it, which is how I have it ready now.

Thanks - this sounds promising.
Your man is listing this - Fiat Punto ELECTRIC POWER STEERING COLUMN 6670 looks like a better fit than the Corsa unit, it's also made by Delphi so is likely the same control-wise...

Yep, that looks like mine, except that I have all the stalks etc.. still attached. Might be worth asking him for a complete one. Whilst I still have the car sitting here, I intend to remove the other end of the coupling from the steering 'rack'. Maybe ask for that too? Or find a Punto at a breaker's yard?

I forgot to say... and the reason that I mentioned him is that I'd asked him if he thought they'd be man enough for a Landy, and it was his reply that he'd had no problems racing etc.. that persuaded me that I'd use mine.

How do you propose to turn the rotational movement to a linear one .
IE where will you attach it to the landrover system.

Blackburn said:

How do you propose to turn the rotational movement to a linear one .
IE where will you attach it to the landrover system.

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Steering box I would assume.

Blackburn said:

How do you propose to turn the rotational movement to a linear one .
IE where will you attach it to the landrover system.

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My plan is to take a s3 column and box, identify which EPAS unit intrudes least into the hard-to-change bits like the bulkhead when spliced onto the top of the s3 column, splice and weld, thus using the existing drop box.
This means that in the event of PAS failure that system simply becomes as it was - unassisted.
This may change as I obtain the bits - plan A was to use the Corsa unit, now the Fiat unit is looking better.... I'm sure there are more.

Then there's the issue of telling the unit how fast the LR's going, and doing battle with the CANBus if it's there.

If anyone knows of an EPAS drop box that can be readily plundered, do tell!

Later: Just discovered the Renault Clio column is also a candidate.......

My project is based on a 110, so I'll be using a non-pas steering box from a 90/110. Column length is not a problem for me.

Awhile back you where worrying about how safe your grand children where in the seats you had fitted.
Do you not think this serious design change will put there lives at risk?

Blackburn said:

Awhile back you where worrying about how safe your grand children where in the seats you had fitted.
Do you not think this serious design change will put there lives at risk?

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No - not really. I make significant design changes all the time so you can be safe.

Castor CEng MIEE MIMechE.

I'll be interested to see how you get on with this. The things that I'd be concerned about is that you may need to strengthen the bulkhead considerably and that putting the power at the steering wheel end of things will put extra strain on the steering relay and steering box. I've heard of steering relay shafts shearing but not sure if those tales are true...

dominicbeesley said:

I'll be interested to see how you get on with this. The things that I'd be concerned about is that you may need to strengthen the bulkhead considerably and that putting the power at the steering wheel end of things will put extra strain on the steering relay and steering box. I've heard of steering relay shafts shearing but not sure if those tales are true...

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The existing steering box & relay take pretty well all that feeds back from the wheels. Ruts, potholes, tramlining etc etc. I suggest that the relay is going to take far more from there than from any assisted column.

Supposing I have a 2ft diameter steering wheel and I put all my weight into it - a not uncommon event when manhandling a series or other early vehicle.
That's 200ft/lb of torque applied. I will bet you that the Corsa unit won't supply much more than that at most, but I admit I haven't checked that out yet.
Containing 200ft/lb of reaction at the bulkhead transit won't be an issue - it really isn't that much. Call it 400 - still not that much when spread a bit; the trick is to not create any stress raisers in the area.

I don't want to make light of the mechanical elements - it all deserves proper consideration, but I think the principal issue will be control - obtaining and scaling the road speed feedback and not overdoing the degree of assistance at any particular speed. So it will be a control proportioning issue, I believe. We shall see!

Meanwhile if anyone has an old s3 steering column going cheap somewhere close to Stroud, I'd be happy to know.

The most I have to swing on my steering wheel is when I'm parking the bugger - so I tend to rock it to make life easier (for me and the steering box/relay). If the PAS couldn't make that a piece of **** with one hand then I'd suggest that it is a waste of time and effort - it has to be able to raise that amount of torque - every time you need to park...

dominicbeesley said:

The most I have to swing on my steering wheel is when I'm parking the bugger - so I tend to rock it to make life easier (for me and the steering box/relay). If the PAS couldn't make that a piece of **** with one hand then I'd suggest that it is a waste of time and effort - it has to be able to raise that amount of torque - every time you need to park...

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Indeed. I have a large build (XXL according to the T shirts) and I am applying maximum heave-ho. I'm exhausted after a complicated parking routine!
How the hell smaller persons manage, I don't know...

The issue is that the degree of assistance has to be proportional to the roadspeed - I understand that the Corsa unit has three bands of output torque..and I really don't know what the max is....

To be fair, you don't need assistance when driving normally, and you could in effect turn off the EPAS at anything above 5mph. If you could fit a switch that only enables it in 1st and reverse that should be sufficient. Also from a safety point of view in those gears if something did go wrong the speed would be slow enough to stop in a safe manner anyway.

Do you really find the steering hard enough to warrant all the work? I'm running 235-85-16's with no real need for power steering.

I can't see a small car like a corsa needing more than 40 to 50lbs/ft for the steering, I doubt the EPAS unit your looking at would even make a noticeable difference

If the steering is at all heavy when you're moving then I'd remove and strip down the steering relay. They are a real weak spot as people tend not to keep them topped up with new oil and once the channels in the back of the bushes are blocked with goo the bottom never sees any lubrication leading to heavy sticky steering. As murtle says its just parking that needs PAS and that needs a lot of heft

Murtle raises a point that I forgot to mention.

The Fiat unit takes an input from a dash switch labelled 'City', which, when pressed, ups the power assistance to max. You can almost turn the wheel by blowing it. It switches itself off at about 10mph. Complete waste of time really in a tiny hatchback, but would make a great party trick in your SIII.

boguing said:

Murtle raises a point that I forgot to mention.

The Fiat unit takes an input from a dash switch labelled 'City', which, when pressed, ups the power assistance to max. You can almost turn the wheel by blowing it. It switches itself off at about 10mph. Complete waste of time really in a tiny hatchback, but would make a great party trick in your SIII.

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Lol.

Someone will put HUGE tyres on.....I wonder what the max torsional strength of the relay is...