Not bickering about "Why would anyone want Power steering in a Fiero" Please.
I want powersteering eventually. I like the idea of a quicker ratio with less effort. I have searched and found some good information about the Merkur rack...but I have also found some about the Chevette rack...and it actually sounds easier. My question is: Does anyone know the details of the Chevette rack swap as opposed to the Merkur??? Parts aren't a problem as I work at Advance so the rack would cost me 20% less than retail. I am not afraid of customization but i want to get some good detailed information before I destroy a good powersteering rack thru trial and error. I am not concerned about the hydraulic issues...I have them sorta figured out. Thanks
Nathan

I cant answer your question but I can say that I want PS also. I had a rack from a 3800 2000? but it would not work. The gear was on the wrong side of the rack, so the wheels would turn the opposite direction if I put it in, but I took it apart to see how it worked and found that the 88 rack was so simmular that some of the parts from the 2000 work in the 88! So I saved some of the parts for a rebuild. As for the C4 rack I will get one soon to see if it will work. The 88 rack can be adapted to fit the PS spool as log as the angel is the same, the 88 is almost (70deg) and most PS racks look like 45deg. So the teeth wont line up. But when I get a C4 rack and compare I may be more help. Sorry

I purchased a 87 Chevy Chevette P/S rack from a boneyard. It absolutely won't work. 3" too short and almost all of it on the passenger side.

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- Robert Beaubien
- 87 GT 5-speed (undergoing 3800 Series II SC swap)
- www.fieroexcitement.com
- Rate me if I've been helpful! :)
-

You could always go the "universal" PS rack way.

One thing I would definitely do is use the search function at the top of the page above "Show posts for the last 2 days" and type in power steering in the box. Lots of info there.

Also, The merkur rack will work fine, but, you will need to cut it and then make it flat on 2 opposite sides to accomodate the GM coupling.
Also, you will need to replace the inner tie rods and everything beyond them from the Fiero unit to the Merkur unit. It is supposed to fit. Good luck!

Hope I've helped in some small way!

Phil

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87 FIERO GT 2.8 5spd
0-60 in 6.8 seconds!

[This message has been edited by GTDude (edited 03-18-2003).]

GTDude, I have searched and I did find good information...I just don't think I found enough for me to feel comfortable modifying a $250 power steering rack.
Thanks for the information though.
I will keep looking...the only reason I liked the idea of a chevette rack is I read in a post in the archives, that the chevettes tie rod threading was the same as the Fiero's so all you had to do (as far as the tie rods and ends) was put on a Fiero end?
I have a decent right up on the merkur rack that I found when searching but still vague in a few areas. Thanks again everyone
Nathan

I too am interested in adding p/s. Not for me, but for the wife. If the Fiero had p/s I think she would enjoy driving the Fiero once in a while.

I wouldn't mind adding it. Wonder if the Merkur rack (or something else) will adapt to an 88, as well.
Or maybe Rodney will decide to repro the 88 PS rack. (nudge, nudge. )

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Raydar

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Phuk Phrance! ...until I'm told to change it.

quote Originally posted by RBeaubien: I purchased a 87 Chevy Chevette P/S rack from a boneyard. It absolutely won't work. 3" too short and almost all of it on the passenger side.

BS! Anything works if you try hard enough. With a little machine work, it's no trouble at all to come up with an extension for the right end of the rack. If it bolts to the left Fiero rack mount, half the problem of fitting the thing is done.

You probably could get any power steering rack to work if you are willing to modify it. You only need one that has the same amount of travel as the original one. If it has much less or more, the wheels will turn more or less than stock. This could cause interference problems unless you can device some stops,or if it has too little travel, your turning radius wil be bigger.

The Merkur rack was chosen back in the 80s by the Zimmer people because it was almost identical in length, steered the right direction, could connect to the Fiero steering shaft easily, and had the European "feel" that they were looking for in their Quicksilver conversions. I don't doubt that since this was sourced that another option has not become available, but so far nobody seems to have found one.

It would be quite interesting to find if a simple extension on a Chevette rack would work . . anybody up for it? If not, the C4 rack is worth investigating, too.

In the meantime, the Merkur option is expensive, but it does work. It also has the comfort that it was engineered to be safe--even a minor conversion company like Zimmer needed to make sure that they weren't installing an ongoing liability.

BTW: The Merkur rack will work in the '88 models as well as the 84-87s.

Brian
"Quicksilver" . . . Custom '84 SBC, 4T60, Electro-hydraulic power steering, B&M shifter, Recaro seats

[This message has been edited by bwayne (edited 03-18-2003).]

I am currently fitting a Chevette Rack on the Fiero. I checked them all out and this one appeared to me to be the easiest. Now It is somewhat faster than the standard Fiero Rack, but will give you less turning radius. Probably not a problem. The Chevette rack is 4 1/8" short. Just fabricate 2 2" extensions for each end out of some 3/4" round stock and some sleeves. If anyone is really interested I'll make them for you for a small price. Now you have a rack that will position the inner tie rod ends EXACTALLY where the Fiero ends are.

If you have ever studied the geometry of front ends (I'm getting a huge education here) there is something called the instant center. The tie rod end should point through the instant center and the inner pivot should be in a line between the upper and lower a-arm pivots. If you miss this point, even by a tiny bit, you will have induced bump steer in the front. Couple that to the rear bumpsteer and you will have a very squirrly car. Simply extending the tie rod ends to work you will have a monster. Don't do that!

The bottom line is if you don't have a rack that is EXACTALLY the same length as the FIero one you will have problems.

The next part of the Chevette rack is that the mounts are the same as the Fiero, only different. The pass side rack C-strap has a wider bolt circle to fit over the hydraulic cylinder. You will need to center the rack on the suspension member. This means that a small part of the front tire well will need to be cut off to make room for the valve assembly. A late model GM universal (from Flaming River or others) will fit the Chevette rack and the ID of the column side fits exactally into the end of the sliding steering link of the Fiero once you cut off original universal. Now the steering link is shorter because the universal is shorter, but it is now the same lenght as the Fiero since the Chevette valve body is longer. The next problem is that with the rack centered the steering link now needs an offset and you will need to trim the firewall just a bit to allow it to clear.

This is as far as I've gotten. But when you actually get it all mounted you will have to cut off the rack supports from the frame and relocate them. I suggest doing this with the help of a bumpsteer guage and position the rack BEFORE welding the supports. Guessing at the proper location and height would probably not be quite right.

I had considered just extending one side of the rack by the 4 inches, but I have been unable to locate a suitable boot. ALso I don't like the idea of that much rack extended with no bearing to support it. The way I am suggesting here puts no more load on the bearings than the Fiero rack.

Do you have any pics? Even if they are of the Chevette rack so I can see what you mean when you say the are the same but different. I have not seen the Chevette rack so if you could help me out by showing pics that would be great.

Merkur rack installed...............

Phil

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87 FIERO GT 2.8 5spd
0-60 in 6.8 seconds!

I think I just saw RED! LOL

Where is the P/S pump mounted and are the brackets factory off something or do they have to be fabed?

quote Originally posted by avengador1: This could cause interference problems unless you can device some stops,or if it has too little travel, your turning radius wil be bigger.

FYI, the Fiero has wheel travel stops built in. They are the fingers reaching off the caliper mounting brackets, and they touch an area on the front control arm to limit steering angle.

Electrathon: A pulley pump would be engine mounted (if you're doing a swap, try to include the original pump in that project). You'll have fabricate brackets if you use a stock motor.

My '84 uses an electrohydraulic pump, again with custom brackets. We mounted it above the transmission because the front spaces didn't provide a solid mount point without tearing apart the spare tire area.

Search for "quicksilver" and you'll find a thread from December that has many more pictures. I have ones now of the EH unit, too, that I will post as soon as I have time.

Brian

The purpose of PS in a Fiero should be to improve the quickness. To that extent the Fiero rack I had was 4.25 turns rack to rack and the Chevette PS is 3. The overall travel distance is not as much as the Fiero but I suspect that the Fiero is limited by stops on the suspension and the rack is not allowed to bottom out at each end of travel. Does any one have the diatance traveled by the Merkur rack, total turns lock to lock and distance rack travels in just one turn? Be helpful to determine which would be the best candidate.

As far as cost goes, Auto Zone Chevette rack $75, $90 core charge. Mounts are the same as Fiero. requires some cutting and rewelding of the rack supports. Also requires fabrication of rack extenders. Once you see what that involves, any competent machine shop can make them in 2 hours at $50/hr shop rate (cheaper if you know someone). New universal for the steering link $50. Total cost to install the rack should be under $300. + the pump

The Chevette rack that I got today is not quicker than my stock 88 rack it takes 3.25 turns lock to lock and the stock 88 is about 3. What gives did the Chevette come with a sport rack, did the ratio change over the years or did I just get the wrong rack? I want around two turns lock to lock. The Chevette rack that I got is not worth doing. Maybe a C4 is the one to do. I will look into the C4 before a zimmer type power steering system. The only reason why is just to stay GM if I can.

wcapman you have a PM

Is that a power rack? Wasn't there also a manual rack available for Chevettes?

The number of turns isn't NECESSARILY what has to be smaller. You want turns of wheel/inches of rack travel to be as small as possible. Divide the # of turns lock to lock by the travel of the rack lock to lock and compare this to the Fiero rack.

quote You probably could get any power steering rack to work if you are willing to modify it.

You can probabably get a brick to fly if you put a big enough engine on it too. The limiting factor in deciding on a rack is tie rod travel.

Take an imaginary cone and place it on the end of your rack. If that cone (which represents the necessary travel for your suspension and steering) does not interfere with the frame rails, wheels, or control arms then you are absolutely right. Modify away. If it does, the question is, "why bother"? Get a different rack.

BTW, the stock 88 manual rack is 2.7 turns lock-to-lock, to be exact.

[This message has been edited by Toddster (edited 03-22-2003).]

I just measured the length of rack movement for the Chevette rack and a GT rack, and both have 1 7/16" of tie rod travel per input turn, so the Chevette PS rack is the same "speed" as the Chevette rack. However, the standard rack only moves 1 5/16" per turn, so the GT rack is faster than a stock rack (duh) and the same speed as the Chevette rack. My car will only allow the wheel to turn 3 turns lock to lock before the tire rubs on the sway bar. So my original assesment of the Chevette rack stands. Now the question is is the Merkur rack faster? Can anyone measure the length of rack change for one turn of the input shaft?

Will, yes it is a power steering rack the yard pulled a manual rack first and had to go get a different car and pull the power rack. It has about .5" more total rack travle than my 88 rack and each turn of the Chevette input shaft moved the rack about .1" more than the 88 Fiero. The input side of the rack body is about an inch shorter, and the pison side is about 5.5" shorter for a total 6.5 shorter than an 88 rack. All measurments taken from the center of the driver side mount as that would put the input shaft were the stock Fiero shaft is.

When comparing speed of racks one also has to consider the offset between the centerline of the ball joints and the tie rod end on the steering arm. I don't have an 88 to measure or compare, but I'll go do that tonight if I have time. But if the 88 rack has a shorter rack throw, it sounds like the steering link on the spindle is CLOSER to the centerline of the ball joints than the earlier models. What this may mean for all of us trying to get faster travel it to somehow fit an 88 rack to an earlier model suspension. Without power assist it would increase wheel effort, though.

Hey Knight Rider, yours too? My wife has always refused to drive my fiero because "it's way to touchy and WAY to hard to turn." I have a tie rod end going out now I think. It is a lot easier to turn the wheel and responds a lot slower. When I told her how bad it was handling she thought that I was exaggerating, so I MADE her test drive it to see for herself. When she got back she claimed that it wasn't broken at all, but that it was finally fixed! (shaking head) gotta love women

[This message has been edited by r@venfiero (edited 03-24-2003).]