bajaman

I guess if you want to de-value your car like that, it is your business. I don't get it personally. The car will essentially be worthless to anyone else but you. No one wants a hacked up heap.
Of course, if you plan on keeping it and the marginal gains in non-value-added "cleaning up the engine bay" are what really floats your boat, I say go for it!

Oh yeah, are YOU saying you go 200 mph? Just curious......

Mr. Stock

The following is an e-mail from Bernd Kluessner who is really knowledgeable.

"A few people approached me after my post yesterday. Instead of replying individually to similar questions, I hope it is ok use the list.

Q: Can you forward Chris Wilson's posts from last year?
It's embarassing, but I didn't save them either after I modified my rack. However, I just got off the phone with Chris. He has not been monitoring the list for a few days since he is busy preparing his new (old) Chevron racecar for a track test in England this weekend. He promised to repost everything as soon as possible - including a link to some pictures on his website.

Q: How is the modification done?
That's easy.
- remove rack according to section N in the workshop manual
- remove pinion assembly from gear housing
- remove snap ring, oil seal and upper bearing from pinion
- remove four oil seals from spool valve (in my European manual, the spool valve is not listed as a seperate part, but it can be removed from the
pinion)
- with the spool valve off, you'll see the safety dogs and where to tig-weld the upper and lower halves of the pinion together

This removes the play.
Probably not necessary, but I also removed the oil seal support perches from the spool valve (in a lathe) and reattached the spool valve using Loctite for cylindrical application. The oil seals are no longer needed since there is no oil pressure and they also would add unwanted friction.

Q: What's that divider piston?
Matt, you are right - there is no part labelled 'divider piston' in the manual. Instead, it is part of the rack itself (item #25 in the diagram). The hydraulic forces act on this piston and assist in pushing the rack left or right. I removed it, because it adds unwanted friction and without it, there is no need for an external loop (recirculating hose). I always try to keep things simple.

Q: Can the modification be made to remove the play and still keep the power assist? No. The twisting of the quill shaft is what covers and uncovers orifices in the spool valve, sending fluid pressure left or right. This SAE paper explains the principle of operation of the power steering system far better than I could.

http://www.delphiauto.com/pdf/sae/1999-01-0396.PDF

You might want to investigate aftermarket power steering systems for race purposes like these

www.woodwardsteering.com

Any volunters? Wael? Gordon?


Cheers

Bernd"

Mr. Stock

This is his other post in regards to the quill shaft.

"
I also doubt that the quill shaft will fail but the fact remains that simply removing the PS pump and looping fluid from side to side will only give you a non-functioning power steering -as opposed to a proper manual rack. Possibly one with shiny AN fittings and a fancy hose, but still a non-functioning power steering.

My concern has to do with steering precision (or the lack thereof) more than with reliability.

After reading Chris Wilson's mail last year I also disassembled my rack and here are the facts:

- EVERY input from the steering wheel is transmitted into the rack through a 150mm long and 4mm thick torsion bar connecting the upper and lower part of the pinion.
- Even if this torsion bar (aka quill shaft) should break, there is no immediate danger since mechanical stops on the pinion prevent the two parts from rotating relative to each other more than approx. 5 deg in every direction.
- The torque required to twist the pinion enough to engage the mechanical stops is approx. 30 ft-lb (give or take a few - I wasn't exactly using lab standard equipment)

In other words, depending on the grip situation of the front wheels, you have up to 5 deg of lost motion during turn-in or up to 10 deg play during sudden changes of direction since you first have to unwind it 5 deg and then twist it another 5 deg in the other direction.

Don't know about you guys but I want ZERO PLAY. So, I followed Chris Wilson's recommendation how to modify the pinion. Since I had the whole assembly apart, I even removed the divider piston on the rack which makes a recirculating hose unnecessary. The difference in steering precision, feel and feedback is like night and day compared to the usual, simpler modification.

When Chris posted this a while back, I was surprised at the lack of reaction from the list. Oh wait, it wasn't a "How to polish or chrome-plate your rack tube" .....

Bernd Kluesener"

Mr. Stock

Here is a pic of the quill shaft.

Mr. Stock

There is nothing to get other than the fact that I want a car to drive in a certain way. At least, that is the reason why I modify my car. It is not done to increase the value of resale since it will never be sold. It is for my pleasure of driving.

The top 10 reasons why I removed power steering: (READ in DAVID LETTERMAN's VOICE)

10)I don't need power steering - it is for sissies

9)I can sell the components so I can afford other mods.

8)It decrease the weight of the car.

8)Removing it makes more space in the engine bay making it easier to work on the engine.

7)It reduces parasitic drag thus freeing up a few (fractions) of ponies.

6)Removing it frees up more space for air to flow for cooling.

5)There are one fewer component to fail in the extremely reliable third gen RX-7.

4)You won't ever have to buy any more power steering fluid.

3)You won't ever have to check the power steering fluid level.

2)It's a verrrry cool mod.

but the number one reason why I removed power steering from my third gen( drum roll) is

1)No girly man will ever ask me to let him drive my car.

turbojeff

iTrader: (30)

We took the PS off our TII, left the power rack. IMHO it was fine on the street with 225/50/16 R compound tires.

The thing that made it unacceptable was our intended usage, auto-x. It was impossible to run the car quickly through the salom and other tight stuff. Lots of steering effort required made it difficult to finesse the car.

OTOH, I think it would be fine for higher speed track driving where transitions are slower and steering angles are smaller.

YMMV.

Jeff

ViperEater

bajaman,
yes I have been 200mph in a Hennesy Viper. And secondly The removal of these items saves weight. I could care less about the value. Once you modify a car in anyway you lose money. No original air filter? you just lost money. I'm building a race car so my concerns are my power to weight ratio.

Thanks!

LT1-7

The 2nd gen manual racks have the exact same mounts cause you have to take them off your 3rd gen. Here is the whole conversion for the manual rack...

get the 2nd gen manual steering rack. Switch out the tie rods, the 2nd gen tie rods are too short I think so the 3rd gen tie rods will have to be installed in the 2nd gen rack. Switch the mounts, the 2nd rack has mounts for 6 bolts (4 for one side, and 2 for the other), the 3rd gen has mounts for 4 bolts (2 for each side). I may have it the other way around but you get the idea. It's easy to change out, you don't even need any tools, just pull them off. That's basiclly the whole conversion. I have driven in a 2nd gen with the PS pump taken out and one with a stock manual rack and I can say that the stock manual drives much better and is allot easier to turn at low speeds. The 2nd gen manual rack looks allot cleaner also, no hoses or anything. I also believe it is alittle smaller than the powered rack. I still have some pics of my conversion if you guys want to see

az_lynx

thanks for the info..... post em

blackscorpio

I like the number 1 reason

blackscorpio

ViperEater - where in CT u from

the_glass_man

iTrader: (2)

WTF???
What does this have to do with anything?
You are aware that cars like this have this little thing called depreciation, right?
I guess I shouldn't have "de-valued" my car with coilovers, or an IC, clutch, flywheel, intake, blah, blah, bla bla blah blah.
If you are interested on a return investment, may I suggest buying some land???
A Japanese sportscar isn't a very good investment. If the car was worthless, I don't think I would be getting so many offers.
I also don't care, because I don't ever plan on selling it.
Maybe you should talk to Jim about making his car worthless, or Carroll Shelby, he really messed cars up.

Its your car, do what you want with it. You can put it back on, and its great for racing.
I have no problems turning, parking, at Auto-X or the strip.
My engine bay is cleaner, cooler, and easier to work in.

the_glass_man

iTrader: (2)

Posted to the Big List by Chris Wilson:

I posted a while ago asking about what people did about the quill shaft
when removing the PAS on an FD3S. I was worried that the quill shaft in
the rack would be subject to excessive loads. Most PAS racks work by the
steering column acting down a quill shaft within the part of the rack
drive the bottom of the column bolts to. This TINY twist in the quill
allows the spool valve to rotate relative to the other half of the spool
and hydraulic fluid is allowed in varying volume to one side of the rack
pistons in the ends of the rack. If there is no high pressure PAS fluid
supply (pump removed) the quill shaft turns until the outer part of the
drive is touching the edges of the safety dogs. It is NOT designed to be
continually flexed through the full movement to the safety dogs, which
is what will happen with EVERY turn of the wheel with no pump. it COULD
easily snap giving a load of lost movement and free play at the steering
wheel. I am going to TIG weld mine up at the dog drive to stop the quill
taking ANY loads. I have uploaded pictures of my drive assembly in
pieces so you can see the around 4 mm shaft that those with no PAS pump
are putting their full steering effort through until the dogs are
contacted. i wouldn't be happy with it left like that myself..

http://www.formula3.freeserve.co.uk/quill.zip

--
Best regards,

Chris Wilson
chris@formula3.freeserve.co.uk

ViperEater

blackscorpio,
Fairfield Area, waterbury 4 you right?

es

OK, I'm going to chime in here. I just did the "Chris Wilson" PS removal, and I haven't yet put the rack back in the car, so I can't tell you how I like it.

To do this the rack MUST come out of the car! The radiator might be able to stay, but I'm not sure (look at my avatar!)...

Welding the pinion assy together is scary. Many people wont want to do it because it's hardened metal. From what I've been told you run the risk of cracks forming along the weld since the weld rod expands & contracts at a much different rate. Also you could end up softening the assy through an aneeling process.
BUT, the safety dogs should prevent bad thngs from happening should the weld not hold. I took mine to a very well known welder and he just made me sign a disclaimer. (I will not hold ___ responsible for my bone head actions)

Now removal of the divider piston was pretty easy. Beat the crap out of it with a hammer until it's a mashed mess & then keep at it until it breaks free.

Oil seals no longer needed since there is no fluid. Just replace the boots & grease everything up. I remember getting frustrated at the FSM not pointing out the C-clip at the top of the pinion shaft, so be aware. There is a clip up there so don't go trying to tap the pinion assy out before you pull it.

OK, that's about all I have to say about rebuilding the rack. One note about the 2nd gen non-PS racks. They have a different ratio which makes for more steering wheel travel for the same turning radius. That could come out to be a pain going through a slalom.

Enjoy,
Eric.

93blackrx

Okay guys........call me stupid and a dumb *** but I've read this thread about three times now and I still don't know haw to go about the elimination of the power steering. You see I've got the engine out of the car and don't want to out the power steering back on. So maybe a kind soul could help me a bit. should I do the semmingly easy "loop mod" or do I really need to get some rack thingy welded?

thanks dudes, Matt

ViperEater

Matt.
I'm gonna try the loop like GoneSilent since I already ordered the fittings.
ViperEater

bajaman

Oh...well hell yes, if you are building a race car. I must have missed that somewhere....sorry.

ViperEater

no prob, and alot of people will want to buy it when its done!

bajaman

Yeah, I already agreed that if you are comfy with the mods you do, and you plan on keeping the car, then go for it. But.......to me there are "value added" mods that make the car more desireable, most of those you listed are in this catagory. Then there are the ones that have no value, like removing the air conditioner and power steering. Go ahead and take the headliner and most of the interior out....sure it will "save weight" but it will look like hell.

LT1-7

here is a pic I took awhile back. Look at how much cleaner it looks with no hoses. Doesn't this rack look smaller than the powered rack?

es

Matt, you can do the loop line pretty easily, but you will still be pushing fluid around when you turn the wheel. Also, you will still be twisting the inner part of the pinion gear assy. This is because you're turning a non-functioning power steering system that is designed to align passages to allow fluid to flow. You end up with a heavier feel, and a certain degree of "null". Meaning you turn the wheel with little response until the safety dogs touch forcing the pinion to drive the rack gear.

So there you have it. If you don't want to completely rebuild your steering rack & NEVER go back to power assist with the benifits of response & steering ease, then do the loop line...

If you want the best response the stock geared rack (more desireable) can offer then you do what I & Chris have described.

If you don't care about the gear ratio then slap a TII rack in...

93blackrx

Okay I think I'm starting to understand. Thanks for being so patient with me guys.

Matt

Mr. Stock

The REAL problem with the second gen manual rack is that it is slower than the 3rd gen rack. This has been discussed in the forum previously. I am too lazy to look up the thread.