I know this subject is one that has been chewed on forever. But I need to fine a different why to take care of the problem ,even thought it is not that bad on a Fiero. I wanted to get ride of it completely. I have already modified the right control arm and welded on a bracket . Just wanted some input to what every one else was thinking, Just to you that have to say they make kits already. well don’t want to pay 600.+ for them besides I like to fab things to . when done this would cost me about 150 at most. Now to the op. What I did was welled bracket for the tie rod to the control arm. I used 3/16 steel and fab the brackets to bolt a tie rod I fabricated out of 2 ½ Hiem joints and 1/14 .065 Dom tubing and attach to were the tie rod would mount. this would have the tie rod part of the control arm. So that when the wheel moves up and down the tie rod and pivot points move with the control arm removing any and all bump steer affects . I f you would like I will take pic and post them if not I won’t . So there you go. So what your take on this.

Post a picture, sounds interesting I was thinking of something similar but did you drop the point that the tie rod attaches to the knuckle down to the same level as the control arm? Cuz I think that's the only way to remove all the bump steer because thats the only place that that attachment point can be placed and move with the control arm completely because it is at the center that the knuckle rotates around (where the ball joint is)

For sure post pics. Is this for an 88?

I would assume its for early cars because bump steer is not an issue with the 88s

iT IS FOR A 84 TO 87 AND i WILL POST THEM TONIGHT

quote Originally posted by mcguiver3: I would assume its for early cars because bump steer is not an issue with the 88s

Well, it is with rims wider than stock, at least for me.

quote Just to you that have to say they make kits already. well don’t want to pay 600.+ for them besides I like to fab things to . when done this would cost me about 150 at most.

I am the same way why buy it when ya can build it? Yes def post pics!

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If it works take it apart and find out why

[This message has been edited by 84candyorangeduke (edited 04-09-2012).]

why cant the raer balljoint be replaced with a hinge?
put it on a rotating plate, which can clamped down for the initial alignment.
and remove the tie rod entirely.

TRIED TO POST THE PIC CAN SEEM TO DO IT ANY HELP ON HOW

quote Originally posted by DANH: [img]C:\Users\Barb And Dan\Pictures\Fiero pics\PIC_0030[/img]

Interested as well, for my '87

You'll have to upload image to pic hosting site....I think this site has it's own.

I use imageshack.com, alot of folks like photobucket.com

Bump steer issues on pre-88 Fieros are grossly overstated.

They have more than your typical live-axle car, but are very driveable and it is not a detriment to handling.

What kind of shape is your suspension in?

Do you trust your welding ability with your (and other peoples) lives?

tie rod end mod
tie rod 2
motor mount

[This message has been edited by DANH (edited 04-09-2012).]

you are still going to have bumpsteer. The knuckle is still going to pivot about the ball joint right? So what is going to happen is that the middle of the knuckle (where the tierod is attached) is going to move closer or farther away from the bracket you welded to your control arm as the suspension compresses or rebounds. So the bumpsteer is still going to happen. You dont need to change the bracket, what you need is to lower the point of attachment on the knuckle itself to the same height as where the ball joint attaches to the knuckle. You have it decently close, you might be able to get away with adding washers.

there will be no bump steer .because the tie rod is part of the control arm . the reason bump steer happens was when the control arm move up or down the longer tie rod was not on the same pivot plain. which would the suspension would compress the longer tie rod would push the tire out and when the suspension would extend the tie rod would pull the tire in. what I did was move the mounting point of the tie rod to the control arm and would move as one unit .no turning .

I blame my rear sway bar for my bump steer. I can't prove it but that's where I believe the problem lies. Since it has polyurethane bushings that are cranked down and the front has 27 year old rubber bushings, there is a backwards proportion of force. Front should be stiffer than rear but obviously it isn't. Sway bar is coming off at least at first. I'll evaluate the handling when everything else is updated.

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Jonathan
23K mile '85 notchie w/ 88 cradle, '87 2.8/Getrag, Air, PW, PDL, PM - Still under construction
https://www.fiero.nl/forum/Forum2/HTML/121056.html
I'm not a mechanic but I play one in my garage - me
Power tends to corrupt, and absolute power corrupts absolutely - Lord Acton
Those who hammer their guns into plows will plow for those who do not - Thomas Jefferson
The tree of liberty must be refreshed from time to time, with the blood of patriots and tyrants - Thomas Jefferson

Unfortunately that isnt true because the knuckle doesnt stay at the same angle to the control arm because of the way the strut moves. Otherwise there is no reason for a balljoint. What you have done will help for sure, but it is not completely gone.

If the tierod attached to the KNUCKLE at the same height at which the balljoint pivots only then would the tierod move perfectly with the knuckle and control arm simultaneously and get rid of the bumpsteer

ok, grab the top of the knuckle and change its angle to the control arm and watch the knuckle turn because of the tierod and you will understand what I mean

I SEE WHAT YOU ARE SAYING. i WILL TRY THAT TO NIGHT WHEN i GET HOME, i DID TRY THAT BE FORE THATS WHY I MOVED THE TIE ROD TO THAT POSITION. so if that is the point . I WILL JUST WELD THE BALL JOINT SO IT DOESN`T MOVE PROBLEM SOLVEDWON`T HAVE TO WORRY ABOUT BUMP STEER JUST KIDDING I WILL LET YOU KNOW WHAT HAPPENS.

[This message has been edited by DANH (edited 04-10-2012).]

You all crack me up!

Do you really think that GM engineers did such a poor job on the rear suspension of the pre-88's that your homemade "fixes" will solve the "problem"?

Renew the worn suspension parts and learn to drive!

And the sway bar causing your bumpsteer?

yes I do think they did not use there brains on this. It was on a very tight buget , And did I mention I worked for GM as a test engenerer in Wixom Michigan , So I do have insite on how the platform engineers and the platform managers work and think.

One thing I can say about http://www.westshorefabrica...Fiero-bump-steer.htm it that it works REALLY WELL! Far superior to the RCC solution since I have that on another car and I took them both to the circle track.

Now, I bought them back when the company was HELD and they were $325...I can't believe they are charging DOUBLE now! Holy cow dung!

My advice is to replicate the HELD system and sell it at a reasonable cost. I doubt any of it was patented.

[This message has been edited by lou_dias (edited 04-10-2012).]

quote Originally posted by olejoedad: You all crack me up! Do you really think that GM engineers did such a poor job on the rear suspension of the pre-88's that your homemade "fixes" will solve the "problem"? Renew the worn suspension parts and learn to drive! And the sway bar causing your bumpsteer?

Considering that the whole assembly came out of a POS sedan that wasn't ever designed to take a turn going faster than 30mph, I think so lol.

Hahaha GM took the front end of a car with knuckles that belong in the front with a steering rack attached to them and instead just mounted the tierods somewhere convenient they didnt care at all about it. And if you like to race your car, tiny tiny changes in toe in the rear of the car make it so unpredictable. Sure you can stiffen up the suspension a ton so it doesnt move enough to make much change in toe, but it is just nice to get rid of it because there should not be bumpsteer in the rear ever. the pre 88s toe out when the suspension drops like during braking which is super sketchy.

What I think you should do is make an extension like a cylinder that drops that point down on the knuckle, and then have it welded to a plate which bends 90 degrees and gets bolted to the bolt that goes through the balljoint. That way you could support it enough to not flex or snap the part of the knuckle that the tierod bolts to.

Yea, the rear suspension on the pre-88 was a..."sourceful hack-job". It works just fine for an economy daily commuter to work and back, but if you start thinking about anything sports car, not really happening. The design itself was just not meant to be in the rear with the tie-rods located in a fixed position. It was never "designed" that way, it was just being "sourceful" aka cheap, by using off the shelf parts they already had.

But I agree the sway bar causing bump-steer is wrong, it's actually the opposite. Get a larger sway bar in the front and get back to us.

All I can say is yikes. This will surely make the problem FAR worse then the factory did.

Why would you move the factory FIXED attachment point to a part that moves both up and down as well as inward and outward?

My prediction is that you will have an extreme toe out on compression, and an extreme toe in on extension.

The whole problem with the original concept of the suspension, is that the attachment point for the toe control is higher then the lower ball joint instead of behind it or ahead of it at the same height.

the A-Arm and Toe rod could have been a parallel perfect link, in theory that would lead to consistent toe. Only problem is, that because the arc of the A-Arm and the Strut having a linear movement, the CAMBER of the wheel changes with suspension movement, and the factory toe rod does NOT compensate for that type of movement. If the toe control was attached at an even height with the lower ball joint, on one end, then along the axis of A-Arm movement at the other end, then the change in camber would not result in a change of toe at all. The Aftermarket kit does this perfectly.

But as stated, The factory didn't do THAT bad of a job with it, Camber only changes a lot at the extremes of A-Arm movement, it's minimal mid stroke. Some additional compensations were made by the factory, the toe control rods are a little long, making the car toe in slightly with the extremes of suspension movement, which really isn't all that bad. They also messed with the positioning of them after 84 where they attach to the cradle.

So in theory, this becomes more of an issue when you lower the car putting you closer to the extremes of the suspension arc.

[This message has been edited by Fierobsessed (edited 04-10-2012).]

quote Originally posted by Boostdreamer: I blame my rear sway bar for my bump steer.

A rear sway bar increases rear roll stiffness, which actually reduces the difference in the angle of each lower control arm, reducing the difference in toe between the two sides when the car either rolls or when one side hits a bump. This means your rear sway bar reduces bumpsteer, it doesn't worsen it. By contrast, the rear sway bar increases oversteer which is the tendency for your rear end to swing out on a tight turn. Perhaps that's what you're sensing.

quote Originally posted by DANH: ...even thought it is not that bad on a Fiero... I wanted to get ride of it completely.

Under roll, slight toe-in on the outside rear wheel and slight toe-out on the front outside wheel increases stability by increasing understeer. While it's best to achieve this with bushing compliance rather than with suspension geometry, either way a rear end that steers is not entirely a negative characteristic. To make a noticeable difference in the way your car handles, you'd be better off addressing the rear roll center's lateral and vertical movement.

Just a point of information.........

Held Motorsports, HT Motorsports, has been purchased and relocated to Western Michigan, now called West Shore Fabricators, a part of Arraut Motorsports.

They can be contacted at 616-893-1433 or Richard@westshorefabricators.com

I met them at the recent Daytona show and their products appear to be very well built, and are adding some new products to bolster the product line.

Unfortunately you’re heading in the wrong direction. You’ve shortened the tie rod and it’s not at the same angle as the control arm so as the suspension travels up and down the shorter tie rod will change angle quicker and making the toe out change faster. I get the approach you’re taking but the only way that concept is going to work is if the tie rod is parallel to the control arm and remains parallel for the entire travel of the control arm. The only way to do this, again with the method you’re using, is to have them both the same length and the vertical distance from the ball joint to the tie rod attachment point needs to be the same as the distance from the control arm attaching point to the cradle to where the tie rod attaches to the control arm. It’s actually simple geometry.

Other responses:

DON’T WELD THE BALL JOINT!!!! You need to be able to adjust the toe and if you weld the ball joint you won’t be able to do that.

Yes, I’m quite sure GM engineer’s did such a poor job engineering the Fiero suspension. Truth be known it wasn’t designed as a Fiero rear suspension but a standard GM front wheel drive suspension and was modified to work as the rear suspension in the Fiero. All they did was add the tie rod mounts on the cradle to try and keep the knuckle from turning. The problem is because the tie rod is connected to the cradle further back than the control arm its rate of angle change is different than the rate of angle change on the control arm.

I like the HT motorsport fix.

I tried that . I moved the mounting bracket for the tie rod right on the center line of the control arm pivot. the only problem with that is the the nmounting point on the knuckle is not in the arc of movement of the ball joint. So I went with the mounting it top the control arm. I figured that the strut is at say a 30 decree angle to kunckle. so that would make the wheel when compressing move up and in. I look at the strut mount and the ball joiunt and the lower blot of the strut is in line with the ball joint so that would make the arc about the same. And I did move the wheel both with the tie rod mounted on the frame in the origin position and over the control arm and were I have it now and the only place that the wheel did not trend to turn out was were I have it know. but I must say I did not have the strut hooked up I used my hand as the top mounting point. so I guess I will see. Can`t get anything right if you don`t try and make mistakes on the way.So I hope tthe puck is in the other net not mine. Love the here that horn.

QUOTE:

A rear sway bar increases rear roll stiffness, which actually reduces the difference in the angle of each lower control arm, reducing the difference in toe between the two sides when the car either rolls or when one side hits a bump. This means your rear sway bar reduces bumpsteer, it doesn't worsen it. By contrast, the rear sway bar increases oversteer which is the tendency for your rear end to swing out on a tight turn. Perhaps that's what you're sensing.

END QUOTE

Maybe that's it. All I know is it's CRAZY! I also know that you don't want the rear stiffer than the front. Note the suggestion to get a larger front bar. Mine actually jumped sideways while going down the road in a straight line! It seemed that the rear was getting in a bind and suddenly releasing. That's the best way I can describe it. Anyhoo, I'm working on all that.

Jonathan

quote Originally posted by Boostdreamer: QUOTE: A rear sway bar increases rear roll stiffness, which actually reduces the difference in the angle of each lower control arm, reducing the difference in toe between the two sides when the car either rolls or when one side hits a bump. This means your rear sway bar reduces bumpsteer, it doesn't worsen it. By contrast, the rear sway bar increases oversteer which is the tendency for your rear end to swing out on a tight turn. Perhaps that's what you're sensing. END QUOTE Maybe that's it. All I know is it's CRAZY! I also know that you don't want the rear stiffer than the front. Note the suggestion to get a larger front bar. Mine actually jumped sideways while going down the road in a straight line! It seemed that the rear was getting in a bind and suddenly releasing. That's the best way I can describe it. Anyhoo, I'm working on all that. Jonathan

Is this in your 85 with the 88 cradle swap?

quote Originally posted by olejoedad: You all crack me up! Do you really think that GM engineers did such a poor job on the rear suspension of the pre-88's that your homemade "fixes" will solve the "problem"? Renew the worn suspension parts and learn to drive! And the sway bar causing your bumpsteer?

Right on Joe!

Many a "Masters of Mechanical Engineering" and a number of professional drivers looked over the problem. True, the cost benefit issue must be taken into account prior to manufacturing. Don't ya think those guys did the best they could so they could sell the car and keep thier jobs? I'll bet they gave it a good effort to also keep the product liability down on the Fiero model, there was enough trouble already.

[This message has been edited by Kevin87FieroGT (edited 04-10-2012).]

well when I got home I did as I said. And the set up does not do as I thought. So back to the drawing board. And yes I know about how will the kits on the market take care of bump steer. but when you do not have 600 plus to spend on 200 dollars of product then you do it your self. So I stick with the stock set up or I was looking at mounting the tie rod bracket on the frame and have the tie rod center line right over and alined with the control arm pivot center line and make a bracket that will drop the tie rod mount and aline it with the ball joint.and try that. Thats unless you that are talking so highly of the 600 + dollars bump steer kits wants to send me one at no cost.

I think if you move the mount for the tie rod on the control arm up so that the tie rod is parallel with the control arm you might have a pretty good setup. I’ve come this far

I should just stay out of this, but.................

Having the revised toe link location on the suspension arm is not a solution. As the suspension arm moves up and down, the angle between the knuckle and the arm changes. The angle change will cause the toe link to either push or pull on the knuckle toe link attachment arm and change the toe-in.

Look at the design of the kits on the market. Notice how the link attachment arm is held stationary to the knuckle attachment weldment, and that the entire weldment is then adjusted?

If you are set on this course for your car, look at what has already been done successfully by others and adapt it for your own use.

Why reinvent the wheel?

quote Originally posted by olejoedad: Is this in your 85 with the 88 cradle swap?

The problem was with the main donor for the '85 project, my '87 with the transplanted 2.8. After the "collision repairs" and the alignment that came with it, I knew that car would never be safe again. It was bad before the wreck but it got much worse. Scary stuff. Hopefully I'll avoid all of that with the build of the '85. All new rubber parts, different cradle, sway bar delete (just in case), etc.

Jonathan

I just want to thank all who joined in on this and opened my eyes .i have removed the brackets and link and will at this point and time remain with the factory set up for the tie rod at which point. I can save the money or make my own control arms following the product that is out there. So thanks again. And for those man and yes women that put this car to gather . I just like to clear up One thing I was not talking about you and the job you did on this car put to the bean counters and high ups that only had the bottom line in mind. Because this could have been a car that would have been greater the the vette. I did see at the tech center in Warren , Mi in 89 a vette and a super chagered 2.8 L race and yes the fiero won hands down. This happened on the north side of the center of of 13 mile rd Up a hill. So thanks again evey one. So much for saving a buck. did not do my home work. And yes I am in the corner with the hat on. Have a great day every one.

No big deal here, just makes for good discussion.

Funny how the corporate process works sometimes, sacrafice what could be a great product for one that has established brand power. Not always the best move, in retrospect, but the bean counters seemed to win alot of those battles in the 80's and 90's. Appears GM is slowly starting to listen to the consumer (Corvette/Camaro) with the exception being the Volt (pushed by the goverments involvement).

Hope your car works out ok for you. No matter how you do the suspention they are fun to drive.