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Josh
Josh Reader
1/4/09 3:04 p.m.

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.

Woody
Woody Dork
1/4/09 3:28 p.m.

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.

11110000
11110000 New Reader
1/4/09 3:35 p.m.

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.

neon4891
neon4891 SuperDork
1/4/09 3:49 p.m.

In my neon, anything above parking speeds is ok, of coarse mine de-powered by throwing the belt

noisycricket
noisycricket Reader
1/4/09 4:07 p.m.
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.

Black Stig
Black Stig Reader
1/4/09 4:50 p.m.

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

ReverendDexter
ReverendDexter Reader
1/4/09 4:57 p.m.

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.

iceracer
iceracer Reader
1/4/09 6:02 p.m.

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

Keith
Keith SuperDork
1/4/09 6:36 p.m.
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.

noisycricket
noisycricket Reader
1/4/09 7:09 p.m.
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.

Jensenman
Jensenman SuperDork
1/4/09 7:41 p.m.
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.

11110000
11110000 New Reader
1/4/09 8:28 p.m.
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.

ae86andkp61
ae86andkp61 New Reader
1/4/09 8:35 p.m.

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.

ReverendDexter
ReverendDexter Reader
1/4/09 8:49 p.m.

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.

93celicaGT2
93celicaGT2 Reader
1/4/09 11:24 p.m.

Is that procedure outlined in the miata writeup pretty universal?

A manual rack was not available for my car.

iceracer
iceracer Reader
1/5/09 11:20 a.m.

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.

Jensenman
Jensenman SuperDork
1/5/09 3:29 p.m.

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.

MetricMuscle
MetricMuscle
7/15/12 6:18 p.m.

I'm in the process of de-powering my '96 Miata and I wondered if the PS pump could be used to provide oil pressure to a turbo.

-Independent oil system for the turbo.

-Use an adjustable return style fuel pressure regulator to control desired pressure. Mallory 4309 for example.

-Run 0w20 or 5w20.

-Not much info on the web as to what the bypass valve in a PS pump open at, what pressure range a typical rack runs, GPM or GPH etc.

1st post.

Keith
Keith MegaDork
7/15/12 6:32 p.m.

Don't go to the web, go to the shop manual. PS pressures are really high, in the 1000-1500 psi range and around 3.0 GPM. I think a 1996 Miata runs at 1100 psi.

Miatas have been running turbos off the "normal" oil system for a couple of decades. What problem are you trying to solve?

ransom
ransom SuperDork
7/15/12 6:33 p.m.

Welcome!

[Edit: Keith posted while I was typing; I was mostly thinking out loud while waiting for someone with more useful into to post, and it happened before I even hit Enter...]

I think power steering tends to run at pressures in the 1000psi range... A quick google finds a few mention of 1000psi and one of 1600psi. Not sure what sort of volumes they tend to move.

Seems like overkill for a turbo oiler, and I wonder how PS pumps feel about motor oil. But mostly it seems like pump knowledge that I don't have. Figured I'd offer up my one morsel of knowledge while you're waiting for more feedback.

I half wonder whether it's going to want to move so much fluid and be capable of moving so much fluid at such high pressures that the internal restrictions in the turbo's oiling passages may still result in pressures high enough to blow the seals out...

NGTD
NGTD Dork
7/15/12 8:26 p.m.

My 2002 WRX depowered its own power steering this weekend at a rally about 4 hours from my house.

A little heavy on sharper corners but not bad on the highway.

MetricMuscle
MetricMuscle New Reader
7/16/12 4:53 a.m.

My thought process on this is....as with any pump, pressure is dependent on a restriction. Wide open, no restriction, and the pressure won't be very much at all. Dead-Headed, 100% restriction, and the sky is the limit until grenade-ation.

Using a return style FPR set at ~35psi, as long as the FPR can flow enough volume, it should be able to control the pressure.

I have this idea so as to facilitate mounting a turbo remotely which will need a scavenge pump of some kind regardless of how it is supplied. The Miata power steering pump provides pressure to the rack as well as vacuum to the reservoir to scavenge fluid from the rack because the rack is below the pump/reservoir assembly.

Power steering fluid is petroleum based so I see no problem. I suppose a turbo would function with PS fluid running thru it.

MetricMuscle
MetricMuscle New Reader
10/16/12 8:34 a.m.

Could someone confirm my assumption that a power steering pump does actually create suction on the return side to evacuate/scavenge the fluid from the rack back to the fluid reservoir?

tuna55
tuna55 UberDork
10/16/12 8:42 a.m.

I daily drove my 72 GMC without PS for months, and it was fine as it was intended to be manual. It also had a manual tranny and manual brakes. I actually really liked driving it.

I depowered my 84 half ton (V8 auto) by giving up on my pump regulator failure after I replaced the high pressure hose twice. I drove it this way for about two years before I got rid of it. You just had to want to turn. badly. It was manageable for me, but I wouldn't let my Mom or girlfriend (now wife) drive it. You had to kid of be a manly man, so the 'acceptable driver' list included my, stepdad and Dad. It was only really hard when parallel parking in the city. I miss that stupid truck.

yamaha
yamaha Dork
10/16/12 10:01 a.m.

I remember the 65-66 mustangs I've driven, most have been all manual........quite interesting, but those manual racks were fairly fast.

The ti was depowered by the PO, its not bad......although, when I swap the engine, I might try hooking up the PS pump just to see the difference.

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