Retrofitting Power Steering - what is the best option?

Retrofitting Power Steering - what is the best option?

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Discussion

jazzdude

Original Poster:

900 posts

152 months

Tuesday 25th October 2016
quotequote all
I gave it a year, and around town, especially on these narrow roads steering my pride and joy is more of a workout than a cruise.

Fitting a TVR one (if I can find one) from a scrappy may the easiest but it seems ridiculously expensive and leak prone.

So next, I can either go with a Subaru Impreza one, with a few mods, and connect this to a OEM belt driven pump and bottle, or alternatively connect it to either an electric pump from a 106/Saxo or one from an Astra.

Then there is the other option which is to leave the manual rack on the car, and replace the steering column with a modified one from a Corsa B.

Which option should I go for based on ease of installation, overall cost, and the final end result?

jazzdude

Original Poster:

900 posts

152 months

Tuesday 25th October 2016
quotequote all
To be honest, bolting a used Corsa B EPAS system to the car worries me. Even though a hydraulic system maybe older tech, if it goes wrong, it just leaks.

Having a motor attached to the steering column that could decide to turn the wheel if it goes wrong scares me.

Am I wrong?

jazzdude

Original Poster:

900 posts

152 months

Tuesday 25th October 2016
quotequote all
OK I have just had a look at some Corsa EPAS threads and I must admit I am interested.

I have studied the Subaru mod and think that it within my capabilities. How DIYable is the electric system?

The joining of the columns, I think a good machine shop can do that, but I am not clear about a full list of parts and details of how it is fixed to the pedal box.

Does anyone know of a detailed thread I could read and whether buying a complete column and boxes is achievable using those advertised on EBAY for about 100 -120 quid.

I also read that I may be able to buy an assembly thats ready to go one from a couple of specialists that some have spoken about but at over 1k seems very expensive, especially as the Subaru option is, like you said a couple of hundred.


jazzdude

Original Poster:

900 posts

152 months

Tuesday 25th October 2016
quotequote all
ClassiChimi said:
Just to clarify Phazed is slightly lighter than my standard Tvr PS RACK.
it's so subtle it feels almost exactly the same as the Tvr PS rack and I enjoyed its use very much. Peter uses huge great massive tyres too hehe
Do you happen to know what pump he was using?

jazzdude

Original Poster:

900 posts

152 months

Wednesday 26th October 2016
quotequote all
My mini Cooper s has electric steering and it has recently developed a problem.

As you are driving the steering goes rock hard. You can just about still steer the car but anyone with less strength would probably not be able to get it to the side of the road safely.

Quickly turning the car off and on again cures it but as this has started happening a bit more regularly it's going in to a sparky here who will take the system to bits and recondition it.

The subaru / electric pump setup seems to offer the best of both worlds where I understand that the pump shuts off when not needed (trw astra unit)

jazzdude

Original Poster:

900 posts

152 months

Wednesday 26th October 2016
quotequote all
I think I agree that I am also put off with the amount of cutting and welding the Corsa Epas system seems to need, and at the end of the day you still have the manual rack and its longer turning ratio.

I think I have decided to go the Scooby rack with the Astra pump, only in that the pump looks like a very straight forward fit on the crossmember in front of the Y piece, and is an all in one unit.

The Saxo option, with the separate resevoir tank seems a little more of a flaff as I see people prefer to put the pumps in the nose cone, which would mean taking out the radiator and it then being inaccessible if the £30 used part needs changing once it dies, a guaranteed 3 months + 1 day after purchase.

jazzdude

Original Poster:

900 posts

152 months

Thursday 27th October 2016
quotequote all
Do you know where a blow by blow DIY instructable might be for the Corsa installation on a Chim?

I would be very interested to read it. smile

jazzdude

Original Poster:

900 posts

152 months

Thursday 27th October 2016
quotequote all
One thing I liked about the Scooby, Astra/Saxo option, is if the pump packs in, it seems you can just take it out and drop in another unit sourced off EBAY, without a major disruption.

Unless you can do the same with the EPAS unit, ie, change just the motor which I assume is the one item that can pack in, I wouldnt want to be fabricating new steering columns each time.

jazzdude

Original Poster:

900 posts

152 months

Thursday 27th October 2016
quotequote all
One thing I liked about the Scooby, Astra/Saxo option, is if the pump packs in, it seems you can just take it out and drop in another unit sourced off EBAY, without a major disruption.

Unless you can do the same with the EPAS unit, ie, change just the motor which I assume is the one item that can pack in, I wouldnt want to be fabricating new steering columns each time.

jazzdude

Original Poster:

900 posts

152 months

Thursday 27th October 2016
quotequote all
phazed said:
True, my 106/Saxo pump can be changed in less than an hour.

In fact I did as the first pump was a bit noisy, (eBay £20.00) and the later one is silent, (eBay £40.00).
Why did you gop for the Saxo pump instead of the Astra option? Was it easier to locate and install?

jazzdude

Original Poster:

900 posts

152 months

Thursday 27th October 2016
quotequote all
phazed said:
True, my 106/Saxo pump can be changed in less than an hour.

In fact I did as the first pump was a bit noisy, (eBay £20.00) and the later one is silent, (eBay £40.00).
Why did you go for the Saxo pump instead of the Astra option? Was it easier to locate and install?

jazzdude

Original Poster:

900 posts

152 months

Saturday 29th October 2016
quotequote all
This debate has been interesting, thanks all.

Even though I had more or less decided that the Scooby saxo route was the way to go I am still intrigued by the Corsa option. With the cutting of and fabrication I guess I won't fully understand the instructions unless both columns are on the bench in front of me.

I suppose I could buy 2 corsa columns in case I cut something too short but is the tvr one a standard vauxhall model in case something goes wrong there too?

Should the Corsa colum be sought with its ecu unit and what part is the potentiometer, as that part does not show in any photos I have seen. How is the speed measured for the system to adjust the assistance?



And lastly does the existing cowling fit back over the new column and can I reuse the key barrel and stalks?

jazzdude

Original Poster:

900 posts

152 months

Wednesday 2nd November 2016
quotequote all
Brilliant post stevesprint, just what I needed, thanks!!

Ok, so I will look for another TVR column to modify, good idea. I think it is from a Cavalier Mk 3 column but looking on ebay hardly any on there so it might be hard to find one. Is there another Vauxhall that has the same column?

Looking at the side by sides, it seems you weld the top part of the TVR column just under the tilt mech to the Corsa part that has the concertina, then you fabricate some tubes to connect the lower half of the TVR column to the EPAS motor housing. What is not clear is what welding is needed for the internal rods.

Are both the ECU and the potentiometer available at DC Electronics?

The road speed sensor looks strange, as on the Chim the wheel around the prop is castellated in around 15mm increments, I would have to fabricate a new flange to take the extra sensor (which I assume is also from DC electronics).

When you were looking for parts, as a guide, what would you expect to pay for a Corsa B column (Ebay?) and a TVR compatible Vauxhall one?


jazzdude

Original Poster:

900 posts

152 months

Monday 7th November 2016
quotequote all
Great information.

So if you were doing this again, knowing what you know now and the information you now have available, would you say it is straightforward?

From what I see, apart from sourceing the components, the fabrication part looks like:

1. Joining the top end of TVR column (with half ring) to Corsa column.
2. Welding the top part of the TVR tilting bracket to Corsa 'Christmas tree'.
3. Cutting the TVR bottom inside shaft, and welding it to the Corsa one.
4. Fabricating a new 'collapsable'lower outer shaft.
5. Working out and fabricating the pedal box bracket.
6. Fabricating a new bracket to fit second speed sensor to crownwheel.

I am tempted to start this, but the Impreza / Saxo route seems a lot less complicated, cheaper and only needs a splined shaft made hexagonal to work.

And, apparently, it is also very similar in feel to the TVR PAS

Am I missing something?