electric power steering
Discussion
I want to fit power steering to my car and i've not really got the room for the belt driven pump, I would have to do some serious squeezing to get it in so my next move is to use an electric pump, I know a few manufacturers make them mercedes and vauxhall are two does anyone know any others? and any forseeable problems?
I'm using a capri rack
thanks for any info
I'm using a capri rack
thanks for any info
I guess it is probably electric due to the logistics of running piping from the rear 
I dont think I could use an all electric rack as i plan to use a capri rack so i would need a hydraulic type of pump BTW i've seen one where its claimed that the pressure is 70.5 bar which according to info i've got equates to over 1000ibs psi !!!! is it my conversion or is it the 70.5 that's wrong if its right then my hose clip fixing methods out the door!
I've worked on software for both EPHS and EPS systems before and I've posted comments with regards to both before.
EPS (Electric power steering) in kit cars, although not impossible would be a nightmare. The dash (where it is mounted for most systems) needs to be specifically designed to take the loading of the system, early development cars had real problems with them literally ripping the dashboard apart under the large torque that some of these systems can produce.
EPHS (Electro-Hydraulic Power Steering), would eliminate this problem, but also have another challenge of the EPS system, electrical/sensor interface. Most of these systems run off signals provided on the CAN bus from the engine (engine speed/state) & abs (vehicle speed) ecu's. And any other sensors the system may require to provide steering assistance.
Most of these messages are implementation specific and cannot be just swapped from one vehicle to another. I would have thought one of two things are required inorder to 'adapt' the system:
1. The original source code for the system, to be adapted to the signals supplied from the ecu's (if any) fitted to the vehicle. (Highly unlikely!)
2. Design and build an interface ecu which could adapt the signals to those that would be suitable for the EPHS system (would also require knowledge of all signals supplied, would be difficult to get hold of!)
Relocating the pump is going to be a much simpler task than attempting to adapt an EPS or EPHS system to run on your vehicle. And I would highly not recommend attempting to adapt an EPS system to fit your kit car, due to the safety concerns.
EPS (Electric power steering) in kit cars, although not impossible would be a nightmare. The dash (where it is mounted for most systems) needs to be specifically designed to take the loading of the system, early development cars had real problems with them literally ripping the dashboard apart under the large torque that some of these systems can produce.
EPHS (Electro-Hydraulic Power Steering), would eliminate this problem, but also have another challenge of the EPS system, electrical/sensor interface. Most of these systems run off signals provided on the CAN bus from the engine (engine speed/state) & abs (vehicle speed) ecu's. And any other sensors the system may require to provide steering assistance.
Most of these messages are implementation specific and cannot be just swapped from one vehicle to another. I would have thought one of two things are required inorder to 'adapt' the system:
1. The original source code for the system, to be adapted to the signals supplied from the ecu's (if any) fitted to the vehicle. (Highly unlikely!)
2. Design and build an interface ecu which could adapt the signals to those that would be suitable for the EPHS system (would also require knowledge of all signals supplied, would be difficult to get hold of!)
Relocating the pump is going to be a much simpler task than attempting to adapt an EPS or EPHS system to run on your vehicle. And I would highly not recommend attempting to adapt an EPS system to fit your kit car, due to the safety concerns.
I had my Cerbera converted to electric PAS following a fault with the original system.
The original system used a pump that was driven off a jack shaft on the engine. This sheared and it was far cheaper to fit an electric PAS system than to repair/upgrade the original. (engine out/retrofit shaft etc!)
The new part contained both the resivoir/ electric motor and hooked up to the original hoses. Cost about £500 all in.
Not sure who makes the part but it was supplied by joospeed @ www.joospeed.net
The original system used a pump that was driven off a jack shaft on the engine. This sheared and it was far cheaper to fit an electric PAS system than to repair/upgrade the original. (engine out/retrofit shaft etc!)
The new part contained both the resivoir/ electric motor and hooked up to the original hoses. Cost about £500 all in.
Not sure who makes the part but it was supplied by joospeed @ www.joospeed.net
There's a company called D.C.Electronics (I think that's right) who make their own electric PAS with adjustable assistance.
All the gubbins are on the column so you can just use a standard rack and all the linkages.
They advertise in Racecar Engineer magazine, I try and dig their details out.
No idea what the cost is though.
All the gubbins are on the column so you can just use a standard rack and all the linkages.
They advertise in Racecar Engineer magazine, I try and dig their details out.
No idea what the cost is though.
regarding price of complete set up ouch! I knew I should have bid more than £35 for the used merc one on EBAY last week mind you it did go over my budget at £43!!! 
Hi,
Ive just about finished fitting power steering to my Dax Cobra, I was very tempted indeed to go with the Corsa system as they are dirt cheap from scrap yards as they never go wrong and are there for worthless in a scrap car. But having heard from annodomini2 I decided to abort that idea totally, the area around where the Corsa system would fit is vertually all fibreglass with just a skuttle hoop there to mount it to and the though of stress cracks in the fibreglass or what ever else could happen just put me totally off the idea. I instead opted to convert a Pug205 GTI rack, well a mate of mine actually did the work for me on the rack, but it has a ram on the outside so its just a case of cutting the body and arms to the same size as the Dax rack, not quite as easy as that but you see what I mean. Anyhow, as for the pump, we are using a Citreon Saxo electric pump, same as a Pug 206 I think, again very cheap from scrap yards as they are vertually worthless. Cant tell you if it will work OK as yet, still got to connect the pump pressure side up and then wait for a nice day to test it, but see no reason why it shouldn't work,
Phil
Ive just about finished fitting power steering to my Dax Cobra, I was very tempted indeed to go with the Corsa system as they are dirt cheap from scrap yards as they never go wrong and are there for worthless in a scrap car. But having heard from annodomini2 I decided to abort that idea totally, the area around where the Corsa system would fit is vertually all fibreglass with just a skuttle hoop there to mount it to and the though of stress cracks in the fibreglass or what ever else could happen just put me totally off the idea. I instead opted to convert a Pug205 GTI rack, well a mate of mine actually did the work for me on the rack, but it has a ram on the outside so its just a case of cutting the body and arms to the same size as the Dax rack, not quite as easy as that but you see what I mean. Anyhow, as for the pump, we are using a Citreon Saxo electric pump, same as a Pug 206 I think, again very cheap from scrap yards as they are vertually worthless. Cant tell you if it will work OK as yet, still got to connect the pump pressure side up and then wait for a nice day to test it, but see no reason why it shouldn't work,
Phil
Hi
the reason i haven't considered all electric steering is because i hadn't even heard of it and after reading annodomini 2s piece it's a complete non starter.
The reason i want to use an electric pump is because I haven't got room to use the Capri one, now the thing is that the Capri one is close to 20 years old now so wouldn't have variable assistance at least I think not, but it does beg the question does a belt driven pump maintain constant pressure through any given engine speed ? because the electric one wont if its just a straightforward fitting without any ecu or such thing, an auto electrician friend of mine says he cant see any problems with my theory so far as the pump on a belt type starts to work as soon as the engine starts where as the electric one starts when ign on but make sure its fitted on a seperate relay as they're quite powerful,any thoughts
BTW the blue box with o/t in was a mistake i dont know what its suppose to mean
the reason i haven't considered all electric steering is because i hadn't even heard of it and after reading annodomini 2s piece it's a complete non starter.
The reason i want to use an electric pump is because I haven't got room to use the Capri one, now the thing is that the Capri one is close to 20 years old now so wouldn't have variable assistance at least I think not, but it does beg the question does a belt driven pump maintain constant pressure through any given engine speed ? because the electric one wont if its just a straightforward fitting without any ecu or such thing, an auto electrician friend of mine says he cant see any problems with my theory so far as the pump on a belt type starts to work as soon as the engine starts where as the electric one starts when ign on but make sure its fitted on a seperate relay as they're quite powerful,any thoughts
BTW the blue box with o/t in was a mistake i dont know what its suppose to mean
Although the Capri rack is 20 years old, I think you'll find there must be some sort of inbuilt pressure regulator/release valve in it. I had a 3ltr Capri many years ago 
And I have to say it was one of the nicest power setups I have ever driven. light for low speed and parking, but progressivly heavier as the speed went up
And I have to say it was one of the nicest power setups I have ever driven. light for low speed and parking, but progressivly heavier as the speed went up1000psi sounds about right to me for an old-style hydraulic system. Jubilee clips are definitely out! You can use them on the low pressure pipe from the reservoir to the suction side of the pump and probably for the return from the rack to the reservoir but everything else will need to be metal.
Been away for a while, just reading a few posts. Thought I'd offer some thoughts, the old manual pumps used by fords are regulated for a constant pressure, reaching operating pressure when the car is at about 1500rpm. the return line can indeed be made from your standard rubber fuel line, the pressured delivery can be made from basic hydraulic hose, your local hydraulic specialist can help, I converted an old diesel to a power rack, the pressured run cost me about £30 from my local hydraulic shop, I considered this very reasonable since the job looked very professional and I didn't even get my hands dirty!
Dangerrous
ps most newer power rack and pumps are variable pressure set ups, as previous posts have pointed out.
Dangerrous
ps most newer power rack and pumps are variable pressure set ups, as previous posts have pointed out.
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