De-powering power steering.: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Jan. 4, 2009 3:04 p.m. Josh Reader

It's pretty common among Miata guys, of course that is a very light RWD car that really never needed PS in the first place. Keith has a nice tutorial on the mod:

http://www.flyinmiata.com/tech/depower.php?x=1

I had my rack de-powered the "easy" way for a month or so before I replaced it with an R model manual rack. I sold the rack to a friend who de-powered it the "right" way and it's isn't all that much worse than mine in terms of effort, especially on street tires. He daily drives it without any trouble. If it were legal for STS2 I probably would have done that myself.
Jan. 4, 2009 3:28 p.m. Woody Dork

I've done it twice, once on a 96 Miata and once on a 99 Civic EX.

I loved it on the Miata. It was near perfect.

I liked it on the Civic but it was a lot heavier. When other people drove the car, they hated it.
Jan. 4, 2009 3:35 p.m. 11110000 New Reader

I did it on my Volvo 240, draining most of the fluid and looping the lines. I like the feel, although it is definitely not for the faint of heart (or weak of arms) in a parking situation. As soon as I get rolling more than 5MPH, all heaviness disappears. This is with 225 width tires, obviously larger tires would increase the heaviness at low speeds.
Jan. 4, 2009 3:49 p.m. neon4891 SuperDork

In my neon, anything above parking speeds is ok, of coarse mine de-powered by throwing the belt
Jan. 4, 2009 4:07 p.m. noisycricket Reader

derekshannon wrote:

Has anyone done it for every day use?

Yes. A couple times.

Does the factory (powered) ratio not have a good feel when de-powered?

Is the typical powered ratio not appropriate for doing this?

Depends on application, see below.

(PS, I'm driving a pretty light FWD car and have had a Ford Ranger, Toyota TLC and three Samurais with 33" tiresw/ manual steering and loved it)

I can't really tell the difference in the RX-7 between having power assist, and having the pump removed.

My Impulse was a little heavy at parking lot speeds. It had a tiny steering wheel, though. I just kept telling myself that wrestling the steering was a lot easier than putting the power steering pump back on

My old Ford was essentially undrivable without power assist, and it had slow steering. Also had -3deg camber, 245 width tires, and a 4800lb curb weight.

As soon as I source a spare K-member for the VW, it will be getting a de-powered rack. Haven't tried it on a FWD before.
Jan. 4, 2009 4:50 p.m. Black Stig Reader

I've had cars without it, two in fact.

My Neon had the PS removed, it sucked when parking but was okay once it got going.

My 300zx had a manual rack installed. My belief is that if you're going to remove your PS, a manual rack is really the best option.

Now that I'm heavily involved in motorsports, moreover drifting, I can't imagine life WITHOUT power steering. It makes life SOOOOO nice and makes driving a car SOOO much easier.

-Dave
Jan. 4, 2009 4:57 p.m. ReverendDexter Reader

It's really common for AE86 guys with p/s to "loop the lines" in a faux manual steering conversion, and they say it works well, but for mine, I pulled a manual rack from an MR2.

Personally, I don't like the thought of running a power rack without power. I'd rather run a proper manual rack if that option exists.

I've also seen a unit for Mustangs to decrease the assist given by the power steering... I believe Maximum Motorsports sold a kit to that end, not sure if they still do.
Jan. 4, 2009 6:02 p.m. iceracer Reader

My first question always is "WHY". Manual racks have a slower ratio than P/S racks.
Jan. 4, 2009 6:36 p.m. Keith SuperDork

iceracer wrote:

My first question always is "WHY". Manual racks have a slower ratio than P/S racks.

A depowered power rack doesn't change the ratio.

That said, my Miatas have power steering even though I'm the guy that wrote that procedure for the FM website. It's my preference.
Jan. 4, 2009 7:09 p.m. noisycricket Reader

iceracer wrote:

My first question always is "WHY". Manual racks have a slower ratio than P/S racks.

Which is why you use the power rack, de-powered.
Jan. 4, 2009 7:41 p.m. Jensenman SuperDork

Keith wrote:

iceracer wrote:

My first question always is "WHY". Manual racks have a slower ratio than P/S racks.

A depowered power rack doesn't change the ratio.

That said, my Miatas have power steering even though I'm the guy that wrote that procedure for the FM website. It's my preference.

I think what he's saying is that a rack designed as a manual rack has a different ratio from one designed as a power steering rack. Makes sense; 1st gen RX7's had a 22:1 manual steering box, the GSL-SE power box was 16:1. The power steering box turned faster but took more effort.
Jan. 4, 2009 8:28 p.m. 11110000 New Reader

noisycricket wrote:

iceracer wrote:

My first question always is "WHY". Manual racks have a slower ratio than P/S racks.

Which is why you use the power rack, de-powered.

Right. I could have used the manual rack, even an alternate set of ball joints with less caster, to duplicate a factory manual-steer setup, but less caster and more turns lock-to-lock are not exactly desireable.
Jan. 4, 2009 8:35 p.m. ae86andkp61 New Reader

In an attempt to help answer the why? question: In the case of the AE86, the power rack and manual rack use different knuckles. If you use the manual rack with the power knuckles, you get more steering angle and a tighter turning radius, but high steering effort, which works well for some folks (drifters who get reeeally sideways and still want to recover.) FWIW, this was the factory setup for the AE86 GTV, the model with all of the performance goodies but none of the luxury stuff.

If you run the manual rack, there are more options for aftermarket parts like quick racks, tie rods, tie rod spacers, so you have options for quicker steering and more angle.

If you run the manual rack with manual knuckles, you get more leverage, so the effort is less and feedback is awesome, but without any gain in steering speed or angle, which works well for some folks.

If you run a manual rack and knuckles with a quick rack and aftermarket tie rods, you can get the best of all worlds.
Jan. 4, 2009 8:49 p.m. ReverendDexter Reader

My reason for switching from power to manual was due to rallycross: with the power steering, I couldn't tell when I was steering past the proper angle, and consequently was constantly giving too much input at the steering wheel. With manual steering, there was at least some resistance when I tried to turn further than the wheels "wanted" to go, so I was able to cut my steering inputs, and drop my lap times.
Jan. 4, 2009 11:24 p.m. 93celicaGT2 Reader

Is that procedure outlined in the miata writeup pretty universal?

A manual rack was not available for my car.
Jan. 5, 2009 11:20 a.m. iceracer Reader

I should have worded that a little clearer. When ice racing the steering gets a little crazy so I put a piece of white tape on the steering wheel. I have owned cars with manual steering and cars with power steering with no feel. I have to say, the PS on my Ford ZX2 is the best of both worlds, not over boosted and gives a feel of the road/track.
Jan. 5, 2009 3:29 p.m. Jensenman SuperDork

Front driver guys considering a depowered rack: keep in mind that on many front wheel drive cars torque steer can rear its ugly head particularly if wheel offsets are changed. I have driven an FP Rabbit which would literally yank the wheel out of your hands if you poured on the coal with any appreciable amount of steering cranked in. That one is a rear steer car (the rack is behind the front axle centerline), the owner fixed the torque steer by going to power steering.