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Electric power steering conversion for 6 volt positive ground


roadmaster_56

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Has anyone come across an electric power steering conversion kit for a 6 volt positive ground system?

 

I've got a 48 Chrysler New Yorker that has radials that are grippier and wider than the original 8.20 x 15 bias ply.  Despite stories about little old ladies muscling these front heavy rigs without breaking a sweat, (straight 8's blocks weigh about 800 lbs w/accessories), they weren't fitted with radials....which make these beasts to parallel park.  So, not wanting to give up the benefits of radials, I'm trying to find another solution.  I've seen many add on 12 volt negative systems but no 6v pos systems.  

Thanks for any leads you can provide.

 

David in Santa Cruz

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I think  you like your tires and wheels.  Simple answer to your question is don't parallel park,  Manual steering systems are designed around the surface contact of the wheels.  I doubt you will find a 6v electric steering system.  Your best option, if you want radials is to go to the radial equivalent of a 8.20 x 15.  It is a much cheaper option than backyard engineering a new steering system.  It will be heaver than the original easy steering system, but much better than what you have now.  Also, tire pressure is critical if you are running radials.  Keep it near the maximum pressure listed on the tire.

 

Also, you have to drive a car with manual steering different than one with power steering.  You never try to turn the wheel without the car rolling.  Also, if you are backing out of a parking space, before moving forward, straighten you wheel to the position to want to move forward in before you stop backing up.  It makes a world of difference, just by changing the technique.  

Edited by 61polara (see edit history)
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Have a good front end man go over your steering and suspension, replace worn parts and do an alignment. While you are at it have the wheels trued and the tires balanced, and put on a new set of shock absorbers. Pump up the tires to 32PSI. Your car will steer, drive and ride  beautifully at all speeds. As for steering it at a dead stop, don't steer it at a dead stop. Get it moving even very slowly, a few inches is enough to allow you to steer it easily. This may call for a little forethought as to where you park it. But if you have enough room to open the doors and get out you should have enough room to steer.

 

Buyers of luxury cars back then expected them to steer easily and your car should do so today.

 

I know people who have done this and declared their car transformed. Took away all desire for power steering or "more modern" suspension. Cheaper too.

Edited by Rusty_OToole (see edit history)
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To address the OP's question, as opposed to offering unsolicited advice, I'll point out that electric power steering didn't exist when cars ran on six volt systems.  Even the aftermarket systems available today are based on OEM designs that operate on 12V.  There is virtually no market for 6V positive ground versions of these, so there is no incentive for an aftermarket company to develop one - they'd never recoup their development investment. Unless there is some oddball system that I have not seen before, I suspect that your only option is to contact one of the aftermarket vendors of these units and see if they can build a custom version that uses a 6V motor. The electronics would be the other problem, as they also run on 12V, though it's pretty easy to use a DC-to-DC converter on the circuit to allow it to operate on 6V.  A custom unit won't be cheap.

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In ’46 and ’47, New Yorkers were factory equipped with 7.00 x 15.  In ’48 they came with  larger “low pressure” 8.20 x15’s to improve the ride.  Fenders were modified to accept the bigger tires. 

 

When I first got the Chrysler, it came with L78-15 wide whites bias ply.  Awful….  heavy steering…I’ve piloted  trucks that were easier to steer.  Handling was lousy too. 

 

Because of their age, I replaced them with 205/75 X 15’s radials.  (I won’t go back to bias ply because of the many benefits of radials.)  The 205’s were cheap and meant to be temporary until I found the right tire.  I run them at 48-50 lbs., which results in a hard ride, but somewhat lessons the effort (not enough though).

 

Having driven many vehicles over many years, I’ve always followed the advice of “a moving wheel is easier to turn” when parking…so I creep and turn.

 

From what I’ve read, electric systems require the least amount of “retrofitting hassle” and installation is pretty straight forward…. much less so than a rack and pinion hydraulic system or other alternatives.  

 

I don’t want to change the original 6v pos to 12 v neg because there are specific relays for the Fluid Drive tranny that should be left as is @ 6v.  Otherwise I might have considered 12v neg conversion.

 

FYI….I’ve also got the same issue with another car I own; a 50 Buick Super.  The factory tire spec is 7.60 by 15.  I replaced those tires with appropriate 235/70 x 15 Diamond Back wide whites…. same problem - very heavy at low speed.  In fact you can see the steering wheel give a little when cranking it around for  parking.  Once under way it’s fine.

 

In the case of the Buick, I may try to install the factory designed system from a ’52, (Buick’s first year of power steering)— IF  I can find one.

 

Advice to “just not parallel park” isn’t realistic unless you live in, say….  Montana or Kansas.  Where I live, we have traffic, crowded streets and tight parking lots.  All require low speed agility.    I drive my cars daily for errands and pleasure; and don’t want their use to be limited by really heavy steering.

 

Back to the original question…. where can I find a 6 volt positive ground electric add on steering system?  Other suggestions?   Work around to incorporate 12v system while keeping the 6v?

Edited by roadmaster_56
left word out (see edit history)
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15 hours ago, joe_padavano said:

To address the OP's question, as opposed to offering unsolicited advice, I'll point out that electric power steering didn't exist when cars ran on six volt systems.  Even the aftermarket systems available today are based on OEM designs that operate on 12V.  There is virtually no market for 6V positive ground versions of these, so there is no incentive for an aftermarket company to develop one - they'd never recoup their development investment. Unless there is some oddball system that I have not seen before, I suspect that your only option is to contact one of the aftermarket vendors of these units and see if they can build a custom version that uses a 6V motor. The electronics would be the other problem, as they also run on 12V, though it's pretty easy to use a DC-to-DC converter on the circuit to allow it to operate on 6V.  A custom unit won't be cheap.

I'm afraid you're right about the lack of incentive.......although I bet a lot of aging "baby boomers" (myself included) own the majority of pre and post war 6v cars.  One would think as they age they'd want a little relief from the "heavy steer" and would create demand for a 6v system......just a guess.

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8 hours ago, roadmaster_56 said:

I'm afraid you're right about the lack of incentive.......although I bet a lot of aging "baby boomers" (myself included) own the majority of pre and post war 6v cars.  One would think as they age they'd want a little relief from the "heavy steer" and would create demand for a 6v system......just a guess.

 

The problem is that the few owners in that group who don't care about keeping their cars completely original have already converted to 12V electrical systems - and have probably added A/C at the same time.

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On 12/22/2018 at 8:59 PM, roadmaster_56 said:

 

Because of their age, I replaced them with 205/75 X 15’s radials.  (I won’t go back to bias ply because of the many benefits of radials.)  The 205’s were cheap and meant to be temporary until I found the right tire.  I run them at 48-50 lbs., which results in a hard ride, but somewhat lessons the effort (not enough though)

 

You have 205s at 48-50 lbs. and its hard to steer?! Wow. How much caster does this car currently have? Is there any oil in the steering box?

 

I hope you find what you are looking for, but I doubt it exists. I was wondering how much electricity it might take. I found an article on the subject. Apparently it takes 470w at 12v for a small car, and "EPS systems can easily exceed 100 A using a standard 12 V battery supply." That would be 200 amps on a 6 volt system. I doubt any extant stock 6v systems could support this for long, and even if they could, the brownout effect would be horrendous at idle, when you really need it, and generators don't really charge.

 

I have toyed with the idea of putting a separate 12v negative ground system on a 6 volt positive ground car (to run stereo equipment or whatever). I would have used one of those tiny Kubota alternators and a lawn tractor or motorcycle battery. A little caution is needed because there would be 18 volts (more while charging) between a 12v and a 6v hot wire.

 

In your case, I think it wouldn't be enough. I suspect you would have to find room for a CS130 and a group 29 battery, in addition to the 6 volt stuff. Even then it might not be enough. According to the article, large cars push the limits of what these units can do, and this is not only a large car, but one that is hard to steer.

 

It sounds like hydraulic power steering might be easier.

 

IMHO Saginaw's "variable ratio" power steering box is the greatest thing ever for power assist in full size cars. I understand you can get them for the torsion-bar Mopars now. I wonder if anything like that exists for your car?

 

Article here: https://www.electronicdesign.com/automotive/steering-right-direction

 

Quote

The amount of electrical power required for EPS has limited the system's usage primarily to smaller vehicles. Part of the issue with a 12 V system is getting enough instantaneous power to have a full electric power steering for a large car. “As of today, I think you'll find them on smaller cars and not so much on large ones,” said Phil Headley, chief engineer, Advanced Technology, Continental Automotive Systems.

TRW's electrically assisted steering (EAS) specifically targets the small car segment. The integrated EPS system is a column unit that uses a low inertia permanent magnet ac motor. A worm gear transmits the assist torque from the motor to the steering column. The system provides a maximum assist torque of 70 Nm (rack assist force 8500 N) with peak output power of 470 W. This requires peak battery current of 70 A at 13.5 V. EPS systems can easily exceed 100 A using a standard 12 V battery supply.

 

Edited by Bloo (see edit history)
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3 hours ago, roadmaster_56 said:

I agree.....in the case of Chrysler products with Fluid Drive, I wonder how 12v conversions were made that accommodated the electrics of the tranny.   Anyone done this....?   ...........Anyone? 

 

It should be possible. I have seen attempts, but have yet to see one actually working on 12v.

Edited by Bloo (see edit history)
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9 hours ago, Bloo said:

 

It should be possible. I have seen attempts, but have yet to see one actually working on 12v.

It would seem to me that all you would need is a 12V solenoid.  The rest of the system is just switches that don't care about voltage. Of course, I am the furthest thing possible from an expert on these systems.

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1 hour ago, joe_padavano said:

It would seem to me that all you would need is a 12V solenoid.  The rest of the system is just switches that don't care about voltage. Of course, I am the furthest thing possible from an expert on these systems.

Joe, I think that is the main problem in doing a conversion.  Chrysler never built this transmission in a 12V car.  They switched to the Powerflyte transmission in 1955 when they also changed to 12V.  Many have tried using a voltage reducer on the solenoid with no luck. Possibly the voltage reducer drops the amps below what is needed to hold the plunger out to keep the transmission in the lower gear.  

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1 hour ago, 61polara said:

Possibly the voltage reducer drops the amps below what is needed to hold the plunger out to keep the transmission in the lower gear.  

 

I suspect you are correct. One would likely need to rewind the solenoid coil for a 12V application.

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This could be the solution:  Try to make the World a very progressive place - always be forward thinking.

 

That being said, your tires may just be a little too wide and you want to read the tire carefully and run at maximum tire pressure. 

 

And, most pre-power steering stuff is a back-breaker unless the car is moving. 

 

Unfortunately not many good solutions via 6 Volt and 12 Volt causes is own problems (you could try investigating voltage reduction devices). 

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@Bloo's article is 12 years old. It says EPS was only in smaller vehicles at that time. By now, maybe it is in larger vehicles, e.g. Tesla X: that is a heavy monster. So we need a more recent article!

 

If one could fit something off a more modern vehicle, it might need to be dumbed down a fair bit, to remove all the lane assist stuff, etc.

 

This one has 58 A (peak) current draw at 12 VDC .

http://www.evwest.com/catalog/product_info.php?products_id=363

 

It is for electric vehicles. Remember, most of them are approaching 2000 kg., which is about what your New Yorker weighs. 

 

If you do find one, you will need to change your generator to an alternator.

 

What about changing the motor to a 6V?

Edited by Spinneyhill (see edit history)
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