ecotec swap (Page 65/98)
wftb DEC 25, 03:08 PM
Since you can't really see by the photo , this is what I have done so far : I had to cut down the frame rail because I did not like the slope the upper arms will be at .After cutting , I welded a 1"by1" X 1/8" wall square tube down in to the exposed channel .Then I welded a 2" by 24" 1/8" steel plate along the outer face of the frame rail .This was welded to the square tube as well .Another long plate was welded to the inside of the frame rail .I replicated the shape of the inside of the frame rail by first welding it in the middle and then pulling it in to the rail where it bends with C clamps .I will be welding a 1/4"thick top plate on and a version of the arm bushing mounting frame that you see in the picture will be bolted to the plate with 1/2" grade 8 bolts .The bushing assembly will be adjustable with eccentric washers and mounts where two of the bolts are .This will be the toe adjustment , camber will be adjusted by the cam bolts on the inner arm mounts , identical to the way the struts are adjusted .I was hoping to get more of this done today , but I do not have the 1/4 plate yet .

[This message has been edited by wftb (edited 12-25-2014).]

wftb DEC 30, 06:57 PM
Now I have the inner bushing mounts welded in place .I can now bolt them in place on their perches and start making the upper arms .I still have a lot of boxing and filling in to do , but that will wait till I drop the cradle .There is just not enough room to do a decent job of it with everything in place .
Lunatic DEC 30, 08:08 PM

quote
Originally posted by wftb:

So the car is now in the " work on " position in the garage .This spot was occupied by our 1991 Civic wagon while I built a new stainless steel exhaust , put in a new gas tank and rebuilt the front and rear suspensions .The plan for this winter is :
1- make and install an upper control arm /coilover suspension system
2-Utilize a stock rear knuckle and rear brakes as part of this package .
The reason for this is twofold : I want the lightest suspension possible and I want a parking brake .
The stock disc is very light compared to the 11" lebarron rotors on the back now .The stock rear caliper is a fairly lightweight AL unit .On my fiero , judging by the amount of wear on the rear pads vs the front pads , the rear brakes do not provide any more than maybe 30% of the total braking .And my brakes work really well on the street and on a track .I use the stock MC and booster and proportioning valve .I will probably gain some unwanted rear brake fade but I am not concerned about it . And in the looks department , stock brakes have no cool factor at all .But I am hoping the gains outweigh the losses .No pics for now , my old camera crapped out and still waiting for the new one to come in the mail .



As it appears from your comments and photo's, is it safe to assume that you're building an SLA (short/long arm) rear suspension? If so, are you doing this to gain more negative camber under jounce/compression?

You also mentioned you want the lightest suspension possible. Is it fair to say the extra steel plate added and the upper control arm would make this set up slightly more heavy than stock?

[This message has been edited by Lunatic (edited 12-30-2014).]

wftb DEC 30, 09:55 PM
In the old days we used to call them double wishbones .But yes a SLA is what I am working toward .As far as weight goes , the frame bracing will add about 4 pounds a side .Getting rid of the Held bumpsteer kit and going back to the RCC lower controls arms I used to have on the car will save about 8 lbs per side .The bumpsteer kit works well but it is heavy .I don't know how much going back to the stock disc and brakes on the rear will save but it will be slightly lighter than the 11" disc I have now .And a coilover compared to a strut is always lighter .I will gain the ability to add more negative camber if I want , but I do not know if overall that is an advantage over a strut system .From what I have observed and learned over the years , the more a strut compresses as it leans in to a corner , it gains negative camber .There has to be a reason Porsche uses struts on all 4 corners of the 911 . I do not think an SLA does this , at least not from my experiments on the front of my fiero . What I hope to gain is adjustability and a much better shock / spring unit .Having a more modern style coilover instead of the old strut in there means I can use all the latest technology if I want to .
Lunatic DEC 31, 07:46 AM
Ah yes, I now recall the Held kit that was on the back of your car. It did look a little heavy and bulky. I like where you're going with the rear suspension. I once read an article, redesign a Fiero suspension for better geometry here on PFF. It's a good read if you have a spare hour or two! I'm looking forward to the modifications and if I can assist you with any laser cut components, let me know.
PS-I have a spare set of coil-overs should you want/need them. I think they're only 8" springs but they might work for your application.

[This message has been edited by Lunatic (edited 12-31-2014).]

wftb DEC 31, 03:04 PM
Thanks .I have read pretty well all the suspension related threads over the years and while it probably would be nice too improve on the geometry , there really is not enough room to make much in the way of changes to improve things much .And my car does not suffer from most of the bad things that happen to stock 84-87 fieros .My car does not "squat" under acceleration nor does it dive under braking .I figure the reason for this is that it has been lowered substantially and the engine weight is lower than stock .With much wider tires in the back I can get out of throttle induced oversteer by lifting off the throttle without having to worry about a spin out .So what I hope to do is just replicate the up and down motion I have now but do it with an upper control arm instead of a strut . After my first mock up , I will measure what changes happen as the suspension goes up and down .Then make changes as needed , and then finalize the design .And then I will definitely look to get some pieces laser cut , thanks for the offer .
wftb DEC 31, 05:51 PM
by drilling a hole on each side of the old strut and welding a nut on each side , i have made a mount for the wheel side bushings .Now I can mock up an arm and see how it will move .
wftb JAN 03, 05:33 PM
wftb JAN 04, 12:06 AM
I have now mocked up a set of arms .The inner mount is tack welded in place .What I have to do now is put my old RCC arm on with a stock spindle and see how it moves .With the bump steer arm on and the strut disconnected at the top , the arm seems to move up and down pretty well .But I will not know if I need to make changes until I have it bolted to the RCC arm and take proper measurements as I move it up and down .Then I can use the mock up arm to make a fixture to make two identical finished arms .
wftb JAN 04, 11:26 AM
I needed to check straightness of the arms so I lightly filed down a piece of 1/2 all thread rod lengthwise so it would fit snugly in the 12 mm holes in the bushings . Slid the big end on and this showed I am not quite there yet .The outer ends do not line up straight so I need to fix that before I carry on .