Board logo

Power Steering?
magsy - 2/5/06 at 12:23 AM

Bear with me..

Been thinking about a RT+, saw the cars at the show this weekend and it looks good.

The thing is my old man would be helping with the build and will be expecting to drive it at the end. He had a bike shunt a while ago and is now arm down.

We can work around the gearchange issues (BEC) but power steering is going to be a must.

Is this going to be possible somehow on the RT+?


jollygreengiant - 2/5/06 at 02:12 AM

Use something like the steering column out of the MG-F ( I believe & if I'm wrong then I appologise ) this has electrically assisted power steering operating along the column rather than on the rack.


nitram38 - 2/5/06 at 03:52 AM

Some other rovers do electric assist on the column too. Just do a search on ebay, I have seen some on there.


chockymonster - 2/5/06 at 05:11 AM

Good choice of car, their customer service is fantastic too!.

The MGF option sounds sensible as I would have thought it was then possible to disable it.
Did you mention it to Marc at MNR? I'm sure he could come up with some ideas!


Fatgadget - 2/5/06 at 06:16 AM

Tha Vauxhall Corsa appears to be the favoured leccy power column with the Escort brigade.Some info here


Howlor - 2/5/06 at 06:22 AM

Definately the Corsa option. Most of the rally guys now use this and the odd grasser. Easy to incorporate and small. there is plenty of space on the MNR to fit this, all you will need is t oget mark to adapt the steerign column bracket.

Steve


britishtrident - 2/5/06 at 06:56 AM

Both the Corsa and MGTF have/had electric pas .


However keep the front tyres narrow and he should get on fine without power steering.

The big problem will be lack of self centreing


smart51 - 2/5/06 at 07:04 AM

I work for an electric steering company. EPS is a good product. Ours certainly wouldn't fit in a vortx without a lot of work. I doubt that competitor's products are smaller.

EPS systems are tuned to suit the car that it was designed for. The chances are that the tune wouldn't be ideal for a light weight car. My vortx, with a quickrack, is only heavy at 2 or 3 MPH. At speed it gets quite light. Without a quick rack it would be lighter. See if you can get a drive in one before deciding. Also, Marc is very helpful. Talk to him about it.

Even our smallest systems have a 70A fuse. You wouldn't get away with using a bike battery.

[Edited on 2-5-2006 by smart51]


Ketchup - 2/5/06 at 12:00 PM

lots of the fiat punto's have the electrically assisted power steering in the column.. its a really small unit and they come with quite a nice little collapsable section with a uj on both ends.. the last time i replaced one it was about £150 new from fiat, must be a few in local scrapyards tho, they have been about for a while


Agriv8 - 2/5/06 at 01:05 PM

magsy,

Though the PAS sterring is an option and I am sure marc will be more than happy to go through the options.

Another option is how large is your dad. The MNR cars can have the Quick release wheels fitted . Thinking that
Possibly thinking along the lines of 2 Stering wheels one for yourself and a larger one for your dad swap and change as required.

My V8 ( 205 Rubber ) is probably the heaviest Vortex and I dont find it heavy on a small sterring wheel ( I am a largish chap ) .

I think as mentioned we can get arround it the best thing is have a word with Marc and get up to the Workshop for a chat and a cuppa and we will see what can be sorted out let me know when you are going and I will try and make it over with mine.

Another point is to remeber that even though your dad may require PAS on a tin top - the need may not be there on a Kit car they are very light.

Regards

Agriv8


DarrenW - 3/5/06 at 08:07 AM

quote:
Originally posted by smart51
I work for an electric steering company. EPS is a good product. Ours certainly wouldn't fit in a vortx without a lot of work. I doubt that competitor's products are smaller.

EPS systems are tuned to suit the car that it was designed for. The chances are that the tune wouldn't be ideal for a light weight car. My vortx, with a quickrack, is only heavy at 2 or 3 MPH. At speed it gets quite light. Without a quick rack it would be lighter. See if you can get a drive in one before deciding. Also, Marc is very helpful. Talk to him about it.

Even our smallest systems have a 70A fuse. You wouldn't get away with using a bike battery.

[Edited on 2-5-2006 by smart51]



Who do you work for? TRW by any chance (Holford or Shirley?) I was working on the Gen2 project for a while and will hopefully be doing some bearing work for Gen2.5 in the not too distant future.
I was under the impression that EPS was a very technical animal that required accurate ECU control. The software being tuned for particular vehicles. Is it possible to retrofit eg a modus system into a kit car and get it running?
I have seen EPS powered cars with a city button (girly button) and a motorway setting. Is this done via the ECU?


smart51 - 4/5/06 at 09:47 AM

quote:
Originally posted by DarrenW
Who do you work for? TRW by any chance ?


Yes, I work for TRW. The girly button is a Fiat thing and both our steering for the Stilo and Idea and another system for the Punto have it. It goes to the ECU and changes the tune so that the steering is more "girly".

The tune is made to suit the target vehicle. It is designed to be stable under all conditions with good steering feel. As such, it takes accound of the steering rack ratio and the steering geometry of the target vehicle. It might make a transplant into another car a bit unpredictable, especially if the new car is lighter at the front.

As for a transplant into a seven, you wouldn't have the CAN bus of the donor car. The EPS would be unhappy without the vehcile speed signal, for instance.

EPS is great, when done properly. I don't know is a simple transplant would be all that good.


DarrenW - 5/5/06 at 10:38 AM

Thats a good summary. i too was concerned that EPS would not be a simple transplant.


To be honest i think i would try and do the twin steering wheel idea as suggested. I use a 13" wheel and steering is quite light. Id be tempted to build the car with std steering and get you father to try it with std Sierra wheel or if you want to test first see if the Nordons can let you test drive with a larger wheel and a small wheel for direct comparison. It could take a lot of hassle out of the build. Failing that std hydraulic may be the way to go but it will be extremely light and could lose feel in such a light car.


Thinking further all of the discussion above are for EPS (pure electric), there is also a EPHS option but again this is ECU controlled (basically an electric motor powers the hydraulic pump instead of the engine).

Maybe a BEC with larger wheel would be lighter still.


coozer - 7/5/06 at 11:19 AM

The company I work for manufacters the Corsa column. I know a fair bit about them and I think to fit one to a locost would be quite simple.
All the assist is controlled in the supplied ecu with the output being dependent on the input. Cant see the weight of the vehicle having much of an effect.
The more you put in combined with the load on the wheels the more it gives out. Simple.
All it needs to work is a signal from the engine, eg alternator.
External boxes are only needed if you want to adjust the settings.
It comes in tilt or non tilt, right or left. Although we only make the left hand version I think it will not be a problem for custom instalation.
Almost forgot, we also make all the eps columns for the Toyota Corrolla! Now, that is a neat column with an extension shaft equipped with uj's. Does need the ecu though and thats seperate to the column, unlike teh Opel varietry.

[Edited on 7/5/06 by coozer]


RoadkillUK - 7/5/06 at 12:48 PM

I was driving my locost yesterday and noticed how light the steering was, I'd say that the steering is no heavier than my PAS Xantia.


smart51 - 7/5/06 at 03:30 PM

So the EPS in a corsa is not vehicle speed sensitive then? Still, I guess it works well enough.


coozer - 7/5/06 at 08:55 PM

The steering is sensitive to how much effort goes into the wheel. When you are parked the resistance from the road is greater therefore you put more effort into the wheel. Then when honking along the M1 at 70mph there is little resistance from the front and the eps doesnt give any assist because theres little effort going into the steering wheel.
In the middle of the column there is a torsion bar that twists when an input is applied, the twist is measured by a potentiometer and the more input, the more twist which = more output assist.
The column needs 12V and a signal to tell it the car is on! We replicate that with a signal generator when we bench test them. It's a particular fequency that escapes me at the moment but I'm sure its the kind of signal your alternator kicks out. I will check when I go back to work.
PS. anybody want one??

[Edited on 7/5/06 by coozer]


marc n - 10/5/06 at 07:17 AM

dont have any personal experiance with electric power steering but have heard of people fitting the corsa ones to rally cars and it working ok, think i have a corsa one here with ecu somewhere will have to have a look , from what i remneber it was a small motor on the column shaft

best regards

marc


coozer - 10/5/06 at 10:08 PM

Checked with the designer and the Corsa column does have a spped sensor. It tells the column what speed teh car is going at and selects a different torque map for the motor. Basically the faster you go the weaker the map (if you get my drift) and the assist drops off the faster you go.
It still works Ok though if you dont connect the sensoras it just stays on the default (lowest) map.
I see in this months Classic Ford mag there is a company offering conversions for Mk1 + 2 Escorts for £850! What a rip off, we sell them to Opel brand new for £95!!! And we make a profit on that!