Bumpsteer bracket (Page 3/6)
wftb MAR 16, 01:18 PM
I am now driving the car on the road again and everything is working well . I am very pleased with traction and stability so far .I really think a bumpster bracket like this could be made to work with a stock 84 - 87 control arm .A reinforcing plate welded on the bottom of the control arm where the inside of the arm mounts would make it strong enough . A stock stamped steel control arm is a lot stronger than most people realize .Especially the rear control arms of an 84 -87 fiero , because they were originally designed for the front end of the old front wheel drive X cars .
lou_dias MAR 17, 02:32 PM
Random idea:

If the rear tie-rod is just 2 heim joints connected by a turnbuckle...
Couldn't you attach a flange to the turnbuckle that could connect to a rod assembly that was hinged so it was 2 rods connected in an L shape where the top of the L was attached to your strut tower. The length/ratio of the two legs is there to basically limit the amount that the turnbuckle would be twisted on the fly as your suspension travelled up and down. Hence you'd have the toe self-adjusting to your suspension travel and essentially have a slight "all-wheel steering" effect...
wftb MAR 17, 09:26 PM
I think I would need a diagram to get what you mean .With the suspension I have built , I get pretty good camber gain with the upper A arm and eliminating the strut and going with the coilover .But using a lower control arm like I have built with a stock 84-87 strut style suspension would eliminate the bumpsteer problem without adding the extra weight of the Arrault arms .I am not a big fan of rear steer suspensions .That would be way beyond my design capabilities . Heck , what I have built is probably stretching my capabilities but it is working well so far.

[This message has been edited by wftb (edited 03-17-2016).]

Yellow-88 APR 07, 06:52 PM
Very nice, WFTB.
I've had something similar on the drawing board for some time. You inspire me to finally do it.
One question. Are your inboard control points parallel to the chassis center line?
In the stock pre-88 chassis they where not.

Yellow
wftb APR 07, 08:24 PM
Thanks for the reply .What I did with the inboard pivots of the upper control arms was to make them follow the same line as the lower control arms .It would have been easier to make them paralell to the centre of the chassis , but I had no way to tell what effect that would have on the geometry .So I just copied the angle of the lower arms .I have put about 100 KM on the car so far and I am happy with it . I have not driven the car in a week because of the snow we are still getting up here . I need an allignment to see just how good it is . I am pretty sure all four wheels are pointed in slightly different directions as far as toe goes . I have thought of a way to make a better ball joint adapter . I have some useless spindles (sloppy ball joint holes ) that I can hack the top hole of the strut mount off .Then I could make another ball joint adapter that would give me a much lower king pin inclination angle . And the inner pivots of the upper control arm could be moved outboard about an inch , giving more room for the shift mechanism and the charge piping .Doing this should result in a more stable instant roll centre . I have not noticed any instability with the setup as it is now , but where a problem like this would show up would be on a banked cloverleaf that is on the bumpy side . So that will be next winter's project if it is needed .

[This message has been edited by wftb (edited 04-07-2016).]

wftb JUN 23, 08:37 AM
Going to make a slight change to the design .The clevis is going to be replaced by another heim joint and is going to be mounted to the cradle .On large bumps I am getting flexing of the rear inner arm poly mount .
wftb JUN 29, 02:41 PM





I have now added the new control rods from the bracket to the frame .You can see that I had to hack up the cradle to get the inner heim joint in the right spot .Over next winter I will smooth that out and weld in a vertical brace .For now it is fine , that area is really thick and strong as it is .The best thing I like about this design is it takes the lower control arm out of the equation .Build the bracket for your spindle , add the control rod and you are done .It does not matter what kind of lower control arm you use(except of course the arraut bumpsteer arm) .I did have to use longer bolts to hold the new assembly together .They are available on Ebay .The ones on now are M12 by 90 flange chassis bolts and nuts .I would like slightly longer bolts , these just barely poke out of the nuts right now .I have some on the way ,I will put them in when they get here .
wftb OCT 11, 12:12 AM
Another mod that I have done is I made new upper mounts and now the coilovers sit close to vertical .This made a big improvement in the ease of motion of the suspension .The angle that the shocks were initially on combined with the design of my strut stub adapter caused binding , restricting the amount of travel . To get the same ride height with the new coilover angle , I was able to back off the preload over an inch . Now I can run stiffer shock settings without the gokart no movement feel .Pics are in my thread in the construction zone .Over the winter , I am thinking of mounting the coilovers on the upper control arm .That should improve the motion and get a longer wheel travel .
wftb OCT 12, 01:42 PM
New spring perch , allowing an almost vertical coilover .Big improvement in freedom of motion .
wftb NOV 23, 11:31 PM
The car is now in the garage for the winter .Plans for this year are a better upper control arm mount/adjustment system and a lot of general clean up and paint .Am I still alone as the only one that has done this ? Would be nice to see what other people have done along the same lines....