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Thoughts on de-powering the rack?

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Old 07-16-2011, 06:28 AM
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Default Thoughts on de-powering the rack?

Anybody done this: Flyin' Miata Guide'?

I have a niggling problem with my power steering hose routing and a recurring leak from a modified 90-degree bend. I'm mighty tempted to ditch the whole thing. I've been driving a lot of sub-1000kg cars with manual steering recently and driving the MX5 again felt floaty light - to be honest, too light.

Has anybody done this mod (either the difficult way above, or the simple looping-the-hoses way)? What did you find? Honest opinions please?

Is there much difference between just draining the fluid (reversible) or chopping the seals off?
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Old 07-16-2011, 07:23 AM
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Lot of threads on this, do some searching.

Many of us, I'd guess over 50%, have depowered racks, and love them. Cutting out the seals makes it a little better, but it's been my experience that people do more than just that seal when they're in there, so it's hard to tell. If I did it again I might just loop the lines.
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Old 07-16-2011, 07:27 AM
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Yep, I found some proper threadnaughts on the subject. Consider this closed! ;-)
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Old 07-16-2011, 11:10 AM
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Old 07-16-2011, 11:25 AM
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Is that the bit I need to weld up after looping? To remove the play?

Or should I be looking at the top quality garden furniture on offer right now?
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Old 07-16-2011, 11:33 AM
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Originally Posted by hustler
That = too much work, and why I bought the plugs to depower my rack. (However, it is probably a superior method) When plugging you need to make sure you get all the air out of the rack. Turn wheel to extremes when tightening the plugs. Plugs were $60 iirc, easy peezy.
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Old 07-16-2011, 11:56 AM
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if you get the shaft welded, just be careful of where you bring it. The guy I brought mine too warped it and now I have a useless rack. I havent been able to find just a pinion shaft for it.
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Old 07-16-2011, 03:23 PM
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Originally Posted by djp0623
That = too much work, and why I bought the plugs to depower my rack. (However, it is probably a superior method) When plugging you need to make sure you get all the air out of the rack. Turn wheel to extremes when tightening the plugs. Plugs were $60 iirc, easy peezy.
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Old 07-16-2011, 04:01 PM
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Half the people like them depowered, half like power steering. I've deleted PS on both the miata's I've owned and have no regrets. It's really no big deal, a little tougher to turn below 5 mph, but nothing major. I let a autocross instructor (miata owner that weighs probably 100lbs more than I do) drive my car and he damn near broke down in tears whining about how hard it was to turn so it's really just personal preference.
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Old 07-16-2011, 04:08 PM
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Originally Posted by djp0623
That = too much work.
PM Bond and see if he agrees with you after driving my car around. My car feels like it's on tank-tracks instead of tires.

I thought it was worth the work and would definitely do it on any track Miata as a requirement before I ever saw the track. I had a ghetto depower by looping the lines and it was OK, but this is like another world of steering feel. You can also dial in resistance on the rack, so you can make the steering as heavy or light as you want. Mine is pretty heavy because it makes it easier to hold steering angle and helped me to slow down my hands.

My ghetto-depowered rack was so tired that I had about 10* of slop when I first depowered it, and 20* after a few years. The PS rack will eventually eat itself without pressure in the bleeder valves.
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Old 07-16-2011, 05:26 PM
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So the piece of metal held in the photo is a welded-up bit to replace the torsion spring thing?
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Old 07-16-2011, 05:36 PM
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Originally Posted by MrBTG
So the piece of metal held in the photo is a welded-up bit to replace the torsion spring thing?
No, the thingy which you think is a spring is thrown in the trash. The "thing" slides over the groove with the holes and uses the tiny bit of slop (in the now welded fittings) to allow fluid to pass through; which is what we know as power steering. Whichever way you turn the slop with the steering wheel determines which side of the rack sees the pressurized fluid. You don't feel it in the car because, you guessed it, the system is pressurized.

FM put it back in their write-up and you don't need it; mine is sitting in the land-fill. We're basically making those two pinion fittings one by welding it.
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Old 07-16-2011, 06:41 PM
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so you can make the steering as heavy or light as you want.
That would be nice. My wife hates the car now because it lacks power steering.
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Old 07-16-2011, 07:01 PM
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Hmm after I depowered it still was not as tight as I wanted it to be. Little undulations in the road at 130mph make me very nervous since the wheel and the car moves around. I want my rack to be tight. I thought this might be cus of alignment but even after getting 0 toe it is stil not very stable.

I liooped my lines. I will buy a properly depowered one but won't do iit myself. I would **** it to death.
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Old 07-17-2011, 11:33 AM
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Originally Posted by Faeflora
Hmm after I depowered it still was not as tight as I wanted it to be. Little undulations in the road at 130mph make me very nervous since the wheel and the car moves around. I want my rack to be tight. I thought this might be cus of alignment but even after getting 0 toe it is stil not very stable.
Unlock the jam nut and add some torque to the pinion tensioner thingy. You should probably take it all the way out and grease it too. Even at 140mph, slamming down on the apron at TWS, my car feels planted with the fresh rack.

I've never done an NB rack but I imagine it all looks the same.
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Old 07-17-2011, 12:10 PM
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Originally Posted by hustler
Unlock the jam nut and add some torque to the pinion tensioner thingy. You should probably take it all the way out and grease it too. Even at 140mph, slamming down on the apron at TWS, my car feels planted with the fresh rack.
I've got mixed feelings about this. On the one hand it works for you and you like the feel. On the other, there are probably better ways to dampen the rack that won't wear it prematurely. That pre-load you've put on the rack collar will wear the nylon cover pretty quickly, and before long most of the preload will be gone.

Have you already dialed in all the caster you can? You can also install an external damper. Another possible way to slow things down is to leave in the piston, fluid, and loop the lines so the piston pumps the fluid from one side of rack chamber to the other. You might be able to adjust the damping by adjusting fluid viscosity.
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Old 07-17-2011, 12:15 PM
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Originally Posted by djp0623
That = too much work, and why I bought the plugs to depower my rack. (However, it is probably a superior method) When plugging you need to make sure you get all the air out of the rack. Turn wheel to extremes when tightening the plugs. Plugs were $60 iirc, easy peezy.
Mechanically, there's no difference between plugging and looping, and neither are in any sense a substitute for a welded pinion shaft.

How the rack is sealed, and how turning the steering wheel translates to moving the wheels, is just not relate-able in any mechanical way.
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Old 07-17-2011, 12:17 PM
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Originally Posted by djp0623
My wife hates the car now because it lacks power steering.
Just another not inconsiderable advantage to a de-powdered rack.
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Old 07-17-2011, 12:29 PM
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Originally Posted by MrBTG
Anybody done this: Flyin' Miata Guide'Has anybody done this mod (either the difficult way above, or the simple looping-the-hoses way)? What did you find? Honest opinions please?
Lots of folks have depowered their racks in a variety of ways. Some have been very pleased, others have not. The difference in satisfaction probably boils down to the quality of the work, and tolerance (or lack of) for less than perfect steering.

If you don't weld the shaft, I wonder about the durability of the rack because there's not much meat in the pinion for transferring steering forces, and what little meat there is gets pounded pretty hard . I would expect the parts of the pinion shaft that transfer forces to deform or even break over time, and become sloppier or even fail. Hustler confirmed the increase in slop with his own ghetto rigged rack. Like Hustler, I don't recommend you skip this step as it's really what makes a depowered rack work properly.

Originally Posted by MrBTG
Is there much difference between just draining the fluid (reversible) or chopping the seals off?
No, so long as no significant fluid remains.
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Old 07-17-2011, 12:58 PM
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I think 99% of Spec Miata drivers in US, UK and NL only drain the fluid and plug. Not sure if welding is allowed. That should give some track (np) record for the poor mans depower?
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