Vauxhall/GM EPAS power steering details
Posted: February 16th, 2012, 6:40 pm
Tommi
As requested Here are some details on the GM/Opel/Vauxhall Electronic power assisted steering (EPAS) power steering retro fitted to my lada.To those who don't know this is a motorised steering column which is triggered to assist when torque is applied via the steering wheel
I though maybe we could do this as a post as it may well intrest other people,I've been asked about it on numerous occasions.
This a rather new system fitted to Corsa B and C models from 2003 onwards A similar system is fitted to Fiat Puntos,but this isn't as good as GM version as its only designed to assist the steering for parking and is switched on and off via a button on the dash. It also generally isnt worth using as its not an easy unit to disassemble for modification (i've had a good look at one). Electronically the GM system uses a engine speed signal and a gearbox speed signal to regulate the tension of the Column. When we retro fit it to our cars we must use a aftermarket control unit which tricks the unit into thinking it has these signals. You can then adjust it with a twiddle knob which you can mount anywhere on your dash board. I've discovered that when you drive at high speed the steering can be very twitchy and its best to turn the unit off but at lower speeds its great. A chum of mine fitted one to an old Series 2 ex army Land rover but as the unit was getting worked hard off road it seemed to overheat and kept cutting out,they don't seem to lend themselves well to off road vehicles which is a real shame.
I wouldn't recommend you fitted this to any car unless you have very good skills with welding, machining and fabrication as its very involved no 2 cars are ever the same,In most cases you have to strengthen the Bulkhead column supports and adapt the pedal box. I've fitted these several times to various cars,Lotus esprit and Humber Sceptre to name a couple of recent ones and its always been a hard but worth while modification..
You can fit these 2 ways,the easy way is to retain the Corsa Column switches,ignition lock. You then must change steering wheel for GM one,This may look silly on an Old/Retro car and doesn't give a good look, you will also need to do extensive modifications to your wiring harness to make this work. They is advantages to this though. You get a modern steering lock and a very good quality ignition switch I did it this way in the Lotus esprit but because its a more modern sports car, GM switches and ignition lock cowling don't look so bad but In my 1965 Humber they look silly.
The other way to do it is to totally remove the corsa column and modify and adapt the one from you modified car. This requires joining the two column shafts together and for this you need a precision machined joint professionally welded together.
If you notice in the lada application the column looks very long this is because the unit physically is too big to fit in the desired gap,But in this application with bucket seats we want a longer steering column anyway bringing it closer to the driver so it works very well.
Its also worth noting that I pay around £80-£100, this is generally the going rate for a second hand unit no more than that. you must also get the brown and blue plugs from the corsa wiring loom to power up the unit.
Have a look at the pictures and give your honest opinion
As requested Here are some details on the GM/Opel/Vauxhall Electronic power assisted steering (EPAS) power steering retro fitted to my lada.To those who don't know this is a motorised steering column which is triggered to assist when torque is applied via the steering wheel
I though maybe we could do this as a post as it may well intrest other people,I've been asked about it on numerous occasions.
This a rather new system fitted to Corsa B and C models from 2003 onwards A similar system is fitted to Fiat Puntos,but this isn't as good as GM version as its only designed to assist the steering for parking and is switched on and off via a button on the dash. It also generally isnt worth using as its not an easy unit to disassemble for modification (i've had a good look at one). Electronically the GM system uses a engine speed signal and a gearbox speed signal to regulate the tension of the Column. When we retro fit it to our cars we must use a aftermarket control unit which tricks the unit into thinking it has these signals. You can then adjust it with a twiddle knob which you can mount anywhere on your dash board. I've discovered that when you drive at high speed the steering can be very twitchy and its best to turn the unit off but at lower speeds its great. A chum of mine fitted one to an old Series 2 ex army Land rover but as the unit was getting worked hard off road it seemed to overheat and kept cutting out,they don't seem to lend themselves well to off road vehicles which is a real shame.
I wouldn't recommend you fitted this to any car unless you have very good skills with welding, machining and fabrication as its very involved no 2 cars are ever the same,In most cases you have to strengthen the Bulkhead column supports and adapt the pedal box. I've fitted these several times to various cars,Lotus esprit and Humber Sceptre to name a couple of recent ones and its always been a hard but worth while modification..
You can fit these 2 ways,the easy way is to retain the Corsa Column switches,ignition lock. You then must change steering wheel for GM one,This may look silly on an Old/Retro car and doesn't give a good look, you will also need to do extensive modifications to your wiring harness to make this work. They is advantages to this though. You get a modern steering lock and a very good quality ignition switch I did it this way in the Lotus esprit but because its a more modern sports car, GM switches and ignition lock cowling don't look so bad but In my 1965 Humber they look silly.
The other way to do it is to totally remove the corsa column and modify and adapt the one from you modified car. This requires joining the two column shafts together and for this you need a precision machined joint professionally welded together.
If you notice in the lada application the column looks very long this is because the unit physically is too big to fit in the desired gap,But in this application with bucket seats we want a longer steering column anyway bringing it closer to the driver so it works very well.
Its also worth noting that I pay around £80-£100, this is generally the going rate for a second hand unit no more than that. you must also get the brown and blue plugs from the corsa wiring loom to power up the unit.
Have a look at the pictures and give your honest opinion