this thread will document my attempt at replacing my rear struts with upper control arms and QA-1 coilovers .this will accomplish 2 things if it works :
1: eliminate bump steer by getting rid of the toe link rod that causes it .
2: get rid of the bulky and heavy strut assembly and replace it with an upper control arm that gives a better tire contact patch under hard cornering .
also , lets face it , struts look like azz .my apolagies to every 911 owner in cyber space but its true .so i have started this project , even though our weather has been so nice i was golfing in shorts today .i will not be damaging any of the stock suspension mounting points .my car generates cornering forces that are very impressive , so i am making sure that i can go back to the way it is now .as far as i know , no one has ever done this to a stock fiero before so i am in uncharted territory . again .some pics .these are west coast fiero delrin control arm bushings that i am modifying to use for this project .the aluminum pieces for the parts you see are in the machine shop getting turned down so i can use them as inner bushings. these have very little deflection and have grease fittings for no squeeks .the outer ones are shown for illustration only , i will be using QA-1 spherical rod ends there because that is the only way i can get toe adjustment .for camber adjustment i will be using eccentric bolts on my spindle adapter.
here you can see the bracket i have made that will hold the upper control arm .it is a long way from finished . but you can see that other than getting rid of some sheet metal , nothing else needs to be destroyed .there is a plate C clamped to the engine cradle that will have some vertical 1"X1" x 1/8" wall square tube rising vertically to this bracket .this will be welded together .then i will weld another flate plate to the upper bracket and that will bolt to the frame rail .this way i can do a cradle drop just by unbolting the top of the coilover and the bracket bolts and not have to do an allignment after .

i am designing as i go , there is a lot of people on the locostusa site that have done similar strut elimination so i hope i can pull this off .here is my arm length and spacing simulater:

constructing the control arm mounting pockets on the upper bracket:



everything for this part is made out of 2" X 1/8" square tubing.my local steel man does not stock U channell in 2" .would have made for a lot less grinding and cutting .he is also my machine shop owner and is working on my inner bushings .i used the sleeve from the bushings to hold my bracket straight while i welded .by the time i get done this project i should be a much smoother welder .now i can put this bracket back on the car and get the angle i want , lock it in place and run the 1" square tube vertical supports and weld them in place .

This looks like an awesome project, best of luck!

My eyes are gonna be glued to this, you do great work!

thanks guys . i am having fun with this project .i have never had a back out plan before .wont get any more done for a few days , back to work...

Be sure to account for the fact that the factory lower control arm pivots are wider and lower at the front than at the rear. This means that the ball joint moves in an arc in the side view and may give you surprising bump steer and/or squat behavior, depending on how your toe link is set up.

[This message has been edited by Will (edited 10-26-2011).]

Hmmm... watching with great interest!

Also watching with great interest. What do you plan to use for a rear upright/knuckle?

the rear hub assembly will be the stock unit that i am using now .the strut will be removed and a piece of U channel steel will be bolted on where the strut joins the stub now .a horizontal piece of U channel will be welded on each side of this vertical channel and that will be where the upper arm (an H style arm) will be attached using QA-1 spherical rod ends .an eccentric strut mounting bolt will be used in one of the vertical holes (one hole will be slotted ) to allow for camber adjustment .toe adjustment will be on the foreword rod end probably using another eccentric .with this arrangement , there will be no need for the toe link that gives us the bump steer now .the coilovers will mount to a sort of double hockey stick style arrangement that will be below and attached to the vertical channel bolted to the stub .this will mean the majority of the load will be still carried by the strong upper stub of the hub assembly and not all by the upper arm and rod ends .i have not determined final locations of everything yet , i am going to get my suspension book out for that .

I can't wait to see what you come up with!

quote Originally posted by wftb: the rear hub assembly will be the stock unit that i am using now .the strut will be removed and a piece of U channel steel will be bolted on where the strut joins the stub now .a horizontal piece of U channel will be welded on each side of this vertical channel and that will be where the upper arm (an H style arm) will be attached using QA-1 spherical rod ends .an eccentric strut mounting bolt will be used in one of the vertical holes (one hole will be slotted ) to allow for camber adjustment .toe adjustment will be on the foreword rod end probably using another eccentric .with this arrangement , there will be no need for the toe link that gives us the bump steer now .the coilovers will mount to a sort of double hockey stick style arrangement that will be below and attached to the vertical channel bolted to the stub .this will mean the majority of the load will be still carried by the strong upper stub of the hub assembly and not all by the upper arm and rod ends .i have not determined final locations of everything yet , i am going to get my suspension book out for that .

Assuming the bolts through the rod-ends will be vertical...

the bolts through the rod end will be horizontal .with the rod end mounting bolts going vertical , the rod ends cant flex enough and will break .maximum deflection of 16 degrees in that orientation .

If the bolts are horizontal, then the rod ends will be loaded axially... not great, but acceptable if you use big enough rod ends...

http://secure.chassisshop.com/partlist/5961/

http://secure.chassisshop.com/categories/5947/

On an 8" control arm, +/- 16 degrees gives you 4.5" of suspension travel.

2.25 up and 2.25 down is not enough travel .a fellow on the locost forum said to use tractor ends .i went and looked today and they are huge ....and dont flex much .i tried to order the ends i wanted from summit and some parts are back ordered .so i may go with a bigger size .

[This message has been edited by wftb (edited 10-27-2011).]

it is with regret i have decided to abandon this project .i am close to making a mock up of the upper arm but i keep looking at where the mount has to go and the relationship to the lower control arm .everything in the herb adams book says that it just will not work right the way i have it figured out .thats not to say that some one else could not figure out something that would work but the conclusion i have come to is that to do this right you would have to redesign the lower control arm and change the way it is mounted .i dont think you can do one without the other , and that is too big of a project for me .the fiero lower control arm front and rear inside mounts are lined up so if you drew a line through the bushings it would hit the front tire .on my locost that was built with a control arm layout similar to the book on how to build it , the same line runs parallel to the centre line of the car .this is true of the upper and lower control arm . i was going to mount my upper arm square to the upper strut mount and orient it to mimic the up and down motion that the strut makes .but that will make the mount angle of the arms look something like this (O for upper and L for lower )
----------------------------------------- L
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
L
sorry for the poor graphics i could not get pip to work to post a diagram .but i think you get the idea . so i have decided to quit while i have more time than money invested .

[This message has been edited by wftb (edited 10-28-2011).]

As an alternative: May I suggest you look @ an '08 Buick Rendeveau (fwd suv)--the forged rear suspension is a self-contained unit, w/coil springs, solid rotor discs brakes, e-brake, etc. Now the '02 Pontiac Grand Prix front bearings/hubs bolt right in, in place of the Buick hubs which have no splines for the driven axles. The G/P vented rotors need to be spaced out .125" to ensure no rub. I've not got to the caliper mount yet. the frame angle on the Buick is nearly parallel & wider than the fiero @ the rear. Also; Buick did make a rr. set up w/all-wheel drive, but the cost was $600.00 bucks more. I got around that & saved $400.00 with G/P stuff. I've not done this set up
under a fiero yet-too many other projects going @ once. Just an idea-Rick

just for the heck of it i thought i would see if these parts are available here in ontario .the GP stuff , no problem .the Rendevous stuff is not available.This was on the ontario auto recyclers association website . a great site to look for used parts .i am going to probably break down and just buy the bump steer correction kit from west shore .got an email saying they are willing to make me a set .