Power Rack and Pinion

For road racing, autocrossing, or just taking that curve in style. Oh yea, and stopping!
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raygreenwood
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Re: Power Rack and Pinion

Post by raygreenwood » Thu Jul 05, 2018 7:40 pm

To answer an earlier question....."does any modern car have electric power steering"......roughly 70% of all cars made currently in Europe and Japan use electric power steering and have for pushing a decade.

As far as I know there are NO VW/Audi vehciles currently made WITHOUT electric power steering. My mk5 jetta (2006) had it and I think all the mk5 vehicles onward have had it. My 2012 Golf has it. A good portion of GM and Ford above economy class and north of about 2008 have it.
Ray

Ol'fogasaurus
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Re: Power Rack and Pinion

Post by Ol'fogasaurus » Thu Jul 05, 2018 10:46 pm

I'm seeing more and more electric steering, front steer sand rails but mostly they are built with IFS.
DSCN0789 copy.jpg
Rear steer.
DSCN0783 copy.jpg
Front steer IFS
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Last edited by Ol'fogasaurus on Fri Jul 06, 2018 9:07 am, edited 1 time in total.

PhillipM
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Re: Power Rack and Pinion

Post by PhillipM » Fri Jul 06, 2018 8:27 am

Longer than that even, many cars over here have been electro hydraulic for 2 decades or so now. Pumps and columns are everywhere, loads of options, We ran Peugeot pumps for many years, switched to a modified Merc unit this year instead

TZepeSH
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Re: Power Rack and Pinion

Post by TZepeSH » Fri Jul 06, 2018 8:40 am

People in Europe used the Audi 80 rack and pinion for power steering. It is similar in shape and dimensions to the 1303 rack and pinion, some little fabrication is needed. But it has an external pump that needs to be driven, and hydraulic hoses to be made.
A more common option I have seen is keeping the normal "worm" steering but replacing the steering column to Opel Corsa B or C (can't remember now which). It has an electric motor directly on steering column, and it is cheap. All sensors are on it, and needs just to trick the speed input (it has different power setting depending on the input PWM frequency - meaning speed signal). Also some fabrication is needed, but overall a very nice solution. Google pics...

PhillipM
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Re: Power Rack and Pinion

Post by PhillipM » Fri Jul 06, 2018 8:47 am

The problem with that setup is the amount of shock loading and wear and tear it gives to the rack and column U/J's - because the rack is taking the entirity of the load rather than the ram - lots of people try it and declare it fantastic, what they don't tell you is how much damage and how many racks they're going through a year on.
I've just switched two of our cars back to electro-hydraulic after the owners were convinced by someone else to switch to the Corsa column - it just caused massive wear issues, and no real advantage over the ram and seperate electric pump setup.

If you've already got a 1303 or aftermarket rack on instead of a box you don't need to mess around changing the lot anyway, just bolt the ram to the rack, rip the shuttle and housing out of whatever PAS car you can find in the scrapyard and just cut the pinion gear off and weld it into the column as a remote shuttle.

Ol'fogasaurus
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Re: Power Rack and Pinion

Post by Ol'fogasaurus » Fri Jul 06, 2018 11:44 am


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raygreenwood
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Re: Power Rack and Pinion

Post by raygreenwood » Tue Jul 10, 2018 5:56 pm

PhillipM wrote:
Fri Jul 06, 2018 8:27 am
Longer than that even, many cars over here have been electro hydraulic for 2 decades or so now. Pumps and columns are everywhere, loads of options, We ran Peugeot pumps for many years, switched to a modified Merc unit this year instead
Not speaking of electro-hydraulic. That is pretty much just a hydraulic system with an,electric pump.

Speaking about straight electric power steering. No oils, fluids, pumps, belts or pulleys. Also not speaking of the systems driven from the column. Talking about electric rack and pinion. Not electro-hydraulic...but electro-mechanical

Here are some pics in an ad.

https://www.ebay.com/i/253592173881?chn ... 9efff9216d


Good article on the differences.
https://www.caranddriver.com/features/e ... st-feature

Contrary to what this article states....I have driven quite a few straight electrics....and in the better designed cars.....there is no loss of road feel. Its partly in the suspension design and partly in the level of assist and sensoring.
VW does it very well. BMW...pretty damn well. Mercedes and many of the luxury Japanese vehicles like Lexus....yep...they are so smooth there is no road feel.
Ray

PhillipM
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Re: Power Rack and Pinion

Post by PhillipM » Tue Jul 10, 2018 9:31 pm

Yes, unfortunately they still have the exact same issue, all the shock loading is delivered through the rack teeth rather than through the usual hydraulic ram, leading to exensive wear and damage in sustained off road use, simply because the shock loads are so high compared to a road car.
They're no different to the column versions for downsides, bar tighter packaging.

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raygreenwood
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Re: Power Rack and Pinion

Post by raygreenwood » Wed Jul 11, 2018 1:27 pm

PhillipM wrote:
Tue Jul 10, 2018 9:31 pm
Yes, unfortunately they still have the exact same issue, all the shock loading is delivered through the rack teeth rather than through the usual hydraulic ram, leading to exensive wear and damage in sustained off road use, simply because the shock loads are so high compared to a road car.
They're no different to the column versions for downsides, bar tighter packaging.
Yep...I can see that as being a problem for off road....having all of the load on the actual pinion and rack. But for a road car....I have actually been quite surprised in their longevity and lack of issues...as compared to old school hydraulic. Ray

PhillipM
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Re: Power Rack and Pinion

Post by PhillipM » Wed Jul 11, 2018 2:35 pm

Yes, they make a lot of sense for a road car, no fluid to worry about, lines, etc.

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