Electric power steering

[roy53]

Whilst looking for a better quality rack i was pointed in the direction of the BMW 3 series rack. As power steering it was of no use for me but would be worth checking out.

Roy

[super6al]

Hi Coops

If you decide to use the MINI pump be sure to check its ok. The early Gen 1 are notorious for failing. Heat from the engine usually gets the blame but my experience was dust from the carbon brushes builds up & eventually shorts the electrics inside. They can be cleaned but it means cutting & re soldering the motor connections. Check Youtube how to do. Its a while since I changed a one & could be wrong but I'm sure the motor uses speed control to vary the assistance. Not sure how you would add the control system to a TR

Alan

[Coops]

    Wow! Thanks for the pump info, no doubt it will be a early example I will try before I fit. Fortunately it cost me nothing, having a mate with a scrap yard is great! As regards the model of the merc sadly I didn’t look, however I have a photo of the bar code on the rack which should be enough surely at a main dealers for an identity check as I would guess it may be on other models? I will add it on to this reply (hopefully!) I did think it likely models may be different in other countries anyway. Regards Alan

[astontr6]

On 2/24/2014 at 7:41 PM, Kevart said:

Hi As anyone fitted electric power steering to a tr6 !!

I phone a company called Litesteer and spoke to their top man he informed me that they had not done a TR6 but have done a number of other series TR's ie. 3's & 4's. I l know a tr4 with this electric conversion and the owner is very pleased with it.

Bruce.

[Coops]

Hi, I don’t know what you guys will think this, I have concerns about fitting electric assistance on the column whilst retaining the original rack and possibly column. The increased torque produced down the column and through the rack can be huge when stationary or at low speeds. I wonder if the standard components are strong enough? The consequences could be grim! I have a Vauxhall combo van with just such a system and I find it excellent, the assistance is phenomenal at low speeds - ideal for parking , but when driving at any speed is perfect. Of course the rack and column are suitably strong. 

[Z320]

Renault Clio II based

 

[Waldi]

4 hours ago, Coops said:

Hi, I don’t know what you guys will think this, I have concerns about fitting electric assistance on the column whilst retaining the original rack and possibly column. The increased torque produced down the column and through the rack can be huge when stationary or at low speeds. I wonder if the standard components are strong enough? The consequences could be grim! I have a Vauxhall combo van with just such a system and I find it excellent, the assistance is phenomenal at low speeds - ideal for parking , but when driving at any speed is perfect. Of course the rack and column are suitably strong. 

Good question.

In Marco’s system below, the forces generated by the PAS will be transmitted to the original rack m/steering system. If it were a PAS designed for say a large truck, this could easily damage the fragile TR rack (and other parts of the system). But with a “small car PAS” like the Clio, this will be less of a concern.

Waldi

[Malbaby]

15 hours ago, Z320 said:

Renault Clio II based

 

Marco....the above is your "old" one that you fabricated?

I am trying to remember if there was a pull apart feature so that the unit could be removed without removing the dash again.

I think that the "Ezisteer" system has a grub screw arrangement to enable separation of  the column/unit for installation and removable. That design would not pass "Engineering Certification" here in Australia.

The only solution that comes to my mind is to fabricate/modify the upper/outer column mount so that the unit can drop down below the dash/fascia. Unfortunately that would entail having a removable section of the lower crash pad.

Edited November 18, 2022 by Malbaby

[Malbaby]

15 hours ago, Waldi said:

Good question.

In Marco’s system below, the forces generated by the PAS will be transmitted to the original rack m/steering system. If it were a PAS designed for say a large truck, this could easily damage the fragile TR rack (and other parts of the system). But with a “small car PAS” like the Clio, this will be less of a concern.

Waldi

I thought that the "torque" was held under the dash via the epas unit mounts to the firewall and body, and not at the steering rack at all.

[Waldi]

You are right in that the tube from the steering column will not be exposed to the torque of the motor as long as the motor is NOT fixed to the tube because in that case it could take some of the exerted torque.

But the torque through the steering axle (which rotates) is transmitted to the rack&pinion and rest of the steering.

Thanks,
Waldi

Edited November 18, 2022 by Waldi
Correction

[Z320]

Hi Malcolm,

I wanted to built the unit to assemble it behind the dashboard, but the space is to narrow there to use tools.

To get it in position I had to remove the dashboard.

Another possibility perhaps could be to bolt the crashpad below the steering column out and cut a pieces of the dashboard out, just as wide as the outer tube of the column.

This maybe could make it possible to turn the unit down and than out.

The answer with the torque I will give later this evening.

Ciao, Marco 

[Z320]

Does it make sense to explain?

Sometimes I‘m tired of doing this….

[John Morrison]

Hi Marco.

Yes it does make sense to explain, and I for one find your engineering skills

and reasoning fascinating.

John.

[RobH]

One problem with assisted steering is that when you reach full lock, the assistance is still there.  If the driver continues to  pull on the wheel at that point, there is a lot of force being applied to the steering mechanism against the travel stops. That is not a good thing at all - particularly when you consider the instances of rack failure recently discussed on the forum. (Where after-market racks have been found not to have the fixing feature of TR OEM ones and have pulled apart, on normal un-assisted systems.) 

 

 

Edited November 18, 2022 by RobH

[harrytr5]

Classic car developments is hydraulic with new rack and components. Fitted 2010 and still superb after thousands of miles. I only notice it when driving standard TR,s.

Regards Harry

[Waldi]

Hi Rob,

I could not have expressed myself clearer. In other words: the torque generated by the PAS should not exceed our manual forces (torque).
Cheers,
Waldi

Hallo Marco,
I’m not sure what disturbs you, this is a forum where we share thoughts/experiences; stay tuned please.
LG, 
Waldi

[RobH]

55 minutes ago, Waldi said:

In other words: the torque generated by the PAS should not exceed our manual forces (torque).

Exactly that - the system needs to lighten steering effort for the driver but not increase force at the rack;  but if a home-made system is cobbled together from parts acquired all over the place, new and/or used, who knows what the characteristics are ?  Who has done the calculations ? Who can measure the result ? 

(That is a general comment, not direct at Marco, who I know is conscientious in getting things right)

 

Edited November 18, 2022 by RobH

[Malbaby]

Looking forward to an "engineering" explanation that even I can understand.

[Z320]

Hi there (Malcolm, I was just writing),

what I wanted to explain is the question "torque from the electric power steerung behind the dashboard".

All my experience, I could be wrong.

First suppose there is no EPAS!

The driver turns the steering wheel, this gives a torque via the inner steering column to the steering pinion (not on the rack).

AND also a torque to to the driver - but a to the other direction! The driver stems powerful against the steering wheel and against the seat.

Its all actio = reaction.

Btw on the outer stering tube is no torque this way, this is why it can be made of soft aluminum.

Next with EPAS.

The EPAS helps the driver and makes steering more comfortable, while the torque to the steering pinion is still the same.

This is the case because the steering does not work different now, the car drives and steers the same way.

But the torque to the driver is much less, so the "saved" torque is on the EPAS now and it has to be fixed against it. Otherwise it would rotate.

This is why I had to fix the motor of the EPAS against the firewall with a torque strap and why I made the outer tube of steel.

The torque is so much powerfull, it can't be held by the original TR clamps of the outer tube of the steering column.

I see some more questions, but this is what I wanted to answer while I rushed to my office.

Ciao, Marco

 

Edited November 18, 2022 by Z320

[Z320]

Please see the black painted clamp and torque strap fixed on the firewall.