OE PAS v EPS

[ELVIS]

first of all I don’t want to start a war over what’s best or indeed a bun fight over coded welding, crash testing, litigation or indeed who’s brother is the hardest!

 My newly acquired LLE has factory PAS and must say I am quite disappointed as I haven’t driven a factory PAS van for some while. My daily is an Amarok and the PAS on that is as light as a feather.

 Am at the point of if a fluid change doesn’t bring joy to my heart, I might actually go EPS. 

 Anyone else done this ? 

 What are the best kits out there? Unlike most fb threads, quality beats price any day. Does anyone make one with a hallsender/VSS for true speed sensitive steering? 

[maxstu]

The factory PAS on my camper is perfectly balanced. Much better and precise than any EPAS l have driven.
Change the fluid and filter to start with. Yes, it does have a filter.
Perhaps it needs a rebuild?

[ELVIS]

Cheers chap. 
 Knew about the filter. Hoping it’s still on its thirty year old original and the fluid is "pooh" but there again it’s had new BW lines in recent years so guess the fluid was done then when they were swapped. 
 I just find it heavy. Tyres are only 215s so not too outrageous and pressures are good. 
just find it very heavy. 

When racks go do they leak pressure past seals and therefore lose efficiency? 

[ZsZ]

just find it very heavy. 

Probably still lighter than a non PS

I am not an expert on PS but beside the seal question, the pump itself can be worn too.

[multisi]

It shouldnt be heavy, there must be a problem, being LHD you are in a good position with the choice of used or a new reproduction racks available, try the pump first.

[Smiffo]

My standard hydraulic PAS is great and I would definitely recommend. No complaints whatsoever.

I’ve never driven an electric PAS example though, so don’t have any comparison. Deffo sounds like something amiss with yours though, if it feels heavy or lacking feel.


Sent from my iPhone using Tapatalk

[R0B]

This

[Mr Bean]

I had the Slaughterhouse EPS installed recently and find manoeuvring at low speed a joy now - better than my Focus.  Feels slightly different at fast cruising speed but I can't quite put my finger on it - no pun intended . Good price, same day installation and excellent service.
Incidentally my insurers - SAGA, gave me a small rebate when I informed them of the modification.  I never expected that.

[cobblers]

My factory PAS caravelle had lovely steering, if it's bad enough that it's bugging you then something isn't right.

I know a couple of people with EPAS on these and they all say that it's a bit over-light when at speed. One of the guys previously owned a van with factory PAS and has started looking into sourcing the bits to do a proper conversion, so I'd definitely think twice before going the other way!

[Jeff J]

I can't really help with your problem but glad I have read this thread because I have had EPS fitted & found that low speed manoeuvring is much easier but driving on motorways etc. is a bit disconcerting as it seems to show up any wear in the steering & you need to be constantly moving the wheel. Thought there was something wrong at first but apparently it's normal. I fitted a switch to the dash so that I can switch it off on long motorway journeys.

[Robsey]

I fitted a switch to the dash so that I can switch it off on long motorway journeys.

I was going to suggest this yesterday, but chose not to post.

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If you are really pedantic, you could get one of the pulse pick-up units that plug into almost all water-cooled speedometers with the clip-on speedo cable.

You can then use the pulses from this to tell the EPAS ECU what speed you are travelling.

Also - if you can get the tachometer pulse converted to 5 volts, then this would give the EPAS the full information that it needs to control the steering properly.
- just as Vauxhall / Opel originally intended.

EPAS X61 - Plug.

Pin 3 - Black = Ignition Live.
Pin 6 - Blue = road speed pulse
Pin 7 - Green = RPM signal.
I would need to verify voltage levels at pins 6 and 7 so that you don't kill the EPAS ECU.

[Jeff J]

I fitted a switch to the dash so that I can switch it off on long motorway journeys.

I was going to suggest this yesterday, but chose not to post.

------------------------------

If you are really pedantic, you could get one of the pulse pick-up units that plug into almost all water-cooled speedometers with the clip-on speedo cable.

You can then use the pulses from this to tell the EPAS ECU what speed you are travelling.

Also - if you can get the tachometer pulse converted to 5 volts, then this would give the EPAS the full information that it needs to control the steering properly.
- just as Vauxhall / Opel originally intended.

EPAS X61 - Plug.

Pin 3 - Black = Ignition Live.
Pin 6 - Blue = road speed pulse
Pin 7 - Green = RPM signal.
I would need to verify voltage levels at pins 6 and 7 so that you don't kill the EPAS ECU.

Mine is supposed to have that built in to the control unit but it is still too sensitive ( or not sensitive enough) at higher speed
 

[Robsey]

With EPAS you are only getting half of the necessary components.

It will have a torque sensor built in for the force that you are putting into turning the wheel, but...
Force applied by you = tell the ECU to give assistance.
No force applied = don't give any assistance.
That is all the torque sensor does (in very basic terms).

The ECU does not get engine load - or more specificly the engine rpm and it does not know the true road speed.
So it relies solely upon the output from the cheapo. pulse widh modulation unit that the retro builders tag onto their EPAS kits

If yours is the sort without the variable resistor (potentiometer), and just has the black box with the jumper removed, then the ecu is being told to give full assistance all the time.

Hence the very light steering.

Kits with the potentiometer give a bit more ability to tune the desired setting, but again, you are using a judgement to guess a setting that may give a "happy medium" regardless of engine rpm and road speed.
The upside is that you can adjust this whilst you are driving, assuming the potentiometer is in a safely accessible location.

As with anything...
If retro-fitter companies wanted to do this properly, they would need to add two extra circuits, which adds more to the kit price tag.

Version 1 - Road Speed -Using Corsa set-up
Corsa use a orange relay-like looking device that acts as a pulse pick-up signal converter and works in conjunction with a toothed wheel or for cheep-skates, the bolt-heads on the CV joints adjacent to the gearbox drive flange.

The pulse converter module.




The Vauxhall part number.


Version 2 - Using VW based parts -
To do this properly, as mentioned earlier, you would get one of the speedometer pulse pick-up gizmos from Brickwerks or GoWesty.
Then wire the speed pulse wire to the EPAS ECU.

A suitable speedo head.



Pick-up unit fitted.



NOT mentioned much here is the engine RPM signal - I am assuming 5 volts here, and it may be possible to use a tacho signal stepped down to an appropriate voltage value. I am not too clued up exactly how the coil or W terminal output is conditioned to drive a tachometer or other ECU input.

After a very quick Google...
Here is something that may help..

https://wiki.autosportlabs.com/CoilX

With both rpm and speed circuits operating, the EPAS ECU will operate as intended, rather than working flat-out or to "best guess" settings.

Bear in mind... the Corsa-C has not been made for 15 years, so parts for these will no doubt begin to dry up from scrap yards in years to come.

-------------------------------------

On another tangent.
If you wanted - in place of a potentiometer, you could fit a switch similar to that used for the blower motor, using three resistances for parking speed, city speeds and motorway speeds.
Standard EPAS retro-fit kit potentiometer is a 100k ohm variable resistor.



You would have to do a bit of research with a potentiometer first.
1 - Parking Speed - Drive the van at a low speed and set the potentiometer to a comfortable level of assistance.
Unplug the potentiometer, and measure the resistance across it's contacts
Write the value down for the resistance value.
2 - City / Urban Speed - Repeat the process for 20 or 30 mph
3 - Motorway Speed - Repeat for your preferred motorway speed. 50, 60 or 70mph...
Finally remove the potentiometer, and purchase upto three resistors - one for each of the readings noted above.
Although you could get away with.
1 - Parking = probably infinite resistance (open circuit)
2 - Urban Speeds = resistance value noted above.
3 - Motorway Speeds = EPAS turned off.
Wire up to suit. - and there you have it.
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So to finish up.

If you can get original factory PAS for the van, then that is always the best option.

If you cannot get the original van parts, then the Corsa kits give you a "get out of jail free, card".
Especially as none of us are getting any younger.

But do remember - you are only getting a "dumb" version of EPAS, not the system that cost developers a fortune to refine for a vehicle about 1/3 the size and weight of the van.

And then there is the potential issues insuring your vehicle with "half" of a non-factory upgrade that was never designed by Vauxhall / Opel to fit a VW...
And fitted without any consent from an appropriate VW technical representitive. (Not all insurers are the same - some will see it as a beneficial upgrade - others will see it as a non-approved modification)

[maxstu]

Wow!

A mega and most interesting write-up, Robsey. Well done.

[clift_d]

I'm in a similar position to ELVIS in that I need to get our power steering working again. What are people's views on the PS racks that are currently available - I think currently the choice is only JP or Mapco?

Or is the best option to get our rack properly refurbished, and if so who would people recommend to approach for this?