ProDarwin
ProDarwin SuperDork
8/27/13 12:47 p.m.

I'm talking about electronic assist racks - NOT electronic PS pumps.

Anyone done one? Any info? Curious for a number of projects that are in my head. Power steering is nice, but packaging is always a pain. Manual steering sucks at low speeds, especially if you drive something with wide rubber, or heavy, or with a lot of caster, etc. My '94 Miata has manual steering and it suuuuuucccks. Its hard to turn, AND the ratio is awful. My S2000 had great steering IMO - I had no complaints about "bad feel". It was a very quick ratio, and comfortable effort.

I'm looking for any info out there to retrofit an EPS rack into a non EPS car. As far as I know, the RX-8, S2K, and NSX are the only self-contained (mechanically) EPS racks out there. The FRS/BRZ has it, but the motor is on the column I think?

I also noticed in another thread today someone posted a link to unisteer which offers some column-mounted conversion kits: http://www.unisteer.com/electric_power_steering.html

GameboyRMH
GameboyRMH UltimaDork
8/27/13 12:52 p.m.

Yep the Toyobaru motor is on the column. The Yaris has one with a "motorized rack" like the NSX, the earliest models run with no sensors and are a popular upgrade on AE86s. Later models need a VSS input IIRC.

turboswede
turboswede PowerDork
8/27/13 1:23 p.m.

A couple of people on the 924board have done it. They used UK GM Corsa/Cobalt columns (which have the electric drive motor portion). They had to have it joined to the 924 upper column with a pinned and welded collar.

To control the motor, there is an aftermarket option available for $100 apparently. The drive typically uses two inputs: 1 for vehicle speed and 2 to tell it the engine is running. The aftermarket box allows you to manually adjust the amount of help the motor provides.

Here's a couple of threads:

www.924board.org/viewtopic.php?t=37749

http://www.924board.org/viewtopic.php?t=36958

http://www.924board.org/viewtopic.php?t=33946

Mk2 MR-2's have electric racks I believe. I like the powered column idea though as that maintains current geometry.

ProDarwin
ProDarwin SuperDork
8/27/13 1:28 p.m.
turboswede wrote: Mk2 MR-2's have electric racks I believe. I like the powered column idea though as that maintains current geometry.

They have electric PS Pumps. Meaning there is still a hydraulic system, which sucks.

GameboyRMH
GameboyRMH UltimaDork
8/27/13 1:32 p.m.

What's so bad about an electro-hydraulic system? Direct electric assist is simpler and more efficient, but EHPS can work just fine and will give you far more options (including the stock Miata PS rack).

z31maniac
z31maniac PowerDork
8/27/13 1:43 p.m.

The 11+ 5.0 Mustangs also have EPAS. Great feel and quick ratio. At least it seemed about 3 turns lock-to-lock, with a tight radius.

Even had Sport, Normal, and Comfort settings.

However, there have been some issues on Mustangs with aftermarket suspension parts causing strange feedback/wobble issues. The only redress has been to buy a new rack from Ford Motorsports which is calibrated differently at around $950 a pop.

chaparral
chaparral HalfDork
8/27/13 2:07 p.m.

A few hours a month in the swimming pool and you wouldn't notice the steering effort any more.

Muscle's somehow just as light as any power steering system. Shouldn't be, but is.

Steering feel is one of those things where you don't know what you've got till it's gone.

Curmudgeon
Curmudgeon MegaDork
8/27/13 2:43 p.m.

Don't forget the role steering wheel diameter plays. Going from 13" to 15" on the Jensenator made all the difference in the world.

Knurled
Knurled UberDork
8/28/13 12:27 p.m.
chaparral wrote: Steering feel is one of those things where you don't know what you've got till it's gone.
GameboyRMH
GameboyRMH UltimaDork
8/28/13 12:38 p.m.
chaparral wrote: A few hours a month in the swimming pool and you wouldn't notice the steering effort any more.

Hey now he could have a physique like me, where his arms would fall off before they got any bigger

yamaha
yamaha PowerDork
8/28/13 2:21 p.m.

In reply to turboswede:

Most likely his best option, it works pretty well.

ProDarwin
ProDarwin SuperDork
8/28/13 6:01 p.m.

I was hoping to see more people come in with posts like turboswede - links to actual swaps. Damn.

chaparral wrote: A few hours a month in the swimming pool and you wouldn't notice the steering effort any more.

I don't think that is the problem.

Keith Tanner
Keith Tanner MegaDork
8/28/13 6:47 p.m.

Easiest thing to do? Sell the manual rack and drop in a Miata PS setup. Lack of steering feel is rarely a complaint, and it'll give you a lighter touch AND a faster ratio. In a couple of hours. The NA Miata manual rack kinda sucks, it was developed in a hurry for people like chaparral and doesn't work as well as the power setup.

The idler pulley that's in place if you have AC but no PS is NLA for Miatas, and is probably worth quite a few bucks. Also, you'll have to change the tie rods at the same time you change the racks. Sell all that together and you'll probably make money on the deal.

Of course, that's the Miata-specific answer. Since you're looking for more general swap questions, I am of no use to you.

sobe_death
sobe_death HalfDork
8/28/13 7:33 p.m.

The Honda Insights have it too, just another option.

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