Thread: swapping MacFerson Strut into rear of car

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Well, this may be a bit different:
I'm putting the FWD engine/trans/suspension package from an '87 Olds into the rear of a '62 Corvair. (well, it was a Corvair once upon a time, long ago...)
I will use the subframe from the Olds as a starting point, as it mounts engine, trans, and lower control arms just fine...
I intend to set it up to bolt into place, rather than weld in hard. This should make life much easier for engine and trans work, and whatever upgrades or revisions turn out to be needed or wanted.

Now, the suspension is typical lower A-arm, upper strut (McFerson strut setup.) This means that a lot of the tuning and adjustments will be different than either a beam axle or a dual-A-arm (sla) suspension.

1: how critical is the strut positioning, assuming that there's enough adjustment to set static camber? Does tilting the strut forward or back in the car affect dive or squat during braking or acceleration? What about tilting the struts toward the center of the car? As long as I can set static Camber, what kind of effects should I expect?

2: Should I set things up so that the A-arm pivots are level the same as in the donor car? Would tilting the pivot axis (by tilting the subframe forward or backward) have some important affect on handling or ride?

Is there a reasonable to visualize the whole process? I'm thinking of pulling the coils out of the struts, mocking it up, and just moving things through the travel to see what happens!

regards
Jay

Thanks, Richard.
I didn't know the Eldo uses upper/lower control arms- what year range was that?
Thanks for the suggestions- I'll just try to provide room for adjustment and go from there.
Here are a few pics of the car- ugly condition, but it has some potential.
http://home.covad.net/~jmaechtlen/cars.htm

regards
Jay

there's some good info in the Suspensions forum of
www.eng-tips.com
Apparantly the A-arm bushings may want to be stiffer, and mounting of steering links/rack may want to be revised.
The site seems to be down at this moment, but normally pretty good. It's really intended for engineers, but there are some racers and hands-on types there too!
jay

Ah, yes- I knew about those!
The engine is mounted lengthwise in those, 3-speed automatic, diff is next to the oil pan, which has a tunnel in it for one of the axle shafts.
That gives a much narrower package than the unit I'm using, and they had plenty of room for the A-arms. With the transverse packaging, it would be real tough to make room for upper A-arms. Even the lower A-arms are pretty short. I guess that's permissable because the strut geometry doesn't change greatly with suspension travel compared to dual A-arm.
Re the 500: Yeah, massive torque! Only a 3-speed, but keep the tall gearing and let the torque launch you like a catapult!
Anyway, the 3.8 should make a pretty good ride even stock, and there's plenty of potential for later on.
regards
Jay

http://home.covad.net/~jmaechtlen/cars.htm

1: for setting up the struts i would first find the centerline of the donor car, and measure the distance between the struts. i would then measure the overall width of the car the settup is going in. the 1/2 difference will be the distance from the outer edge of the car to the strut mount centerline. you also want to get the same suspension travel in the new car as the old one had, so you nee to measure from the ground to the top of the strut mount, and set the new mount at that point in the new car. tilting the strut in this case, being the rear suspension, is undesirable. you want the strut and spring to be as vertical as possible. you dont need any castor(set it at 0), and you need very little, if any, negative camber(i would set it at like -1 degree at most) to aid handling. the A-arms should be parallel to the ground in the rear as anti-dive is settup in the front suspension. as for bushings in the rear i would use a monoball bearing, like you would find in nextel cup cars, instead of urethane or rubber bushings. the reason is you want the rear as stable as possible, and oddly the monoball bearings dont add impact harshness like urethane or metal bushings do.

Thanks for the info!
I still have the donor car, as it will provide fuel pump, master cylinder, portions of wiring loom, and various other items.
I've determined that I can tilt the strut a bit, and still adjust camber out to zero. I think I'll be able to provide adjustment of upper strut mounting, should that become desireable.
Strut travel and A-arm angles- that's what I intend to do!
I haven't determined springing yet, as there won't be room for the stock coils. They take up too much space laterally.
(logitudinal 1/4 elliptic, with shackle hanging off side of strut?
torsion bars? we'll see...)
Thanks for the suggestions on A-arm bushings. To begin with, I will leave the old rubber bushings in it. Later, once some of the many other things are sorted out, I'll worry about such refinements.
Thanks for the suggestions, I appreciate them!
I will update the website- well, maybe by 5/19 or so.
Regards
Jay

Well, it is coming along.
Lots of work just cleaning things up, trimming enough sheet metal and old brackets out of the way, etc.
The car will now sit all the way down over the engine/transaxle/subframe. I'm now beginning to fab mounting points for the subframe to mount into the Corvaiir chassis.
The subframe will be removeable, 'cause that looks like the vbest bet for servicing the engine and trans.

Once the subframe is in, then the upper strut mountings can be done. It looks like the Olds struts will have room for 2" - 2 1/2 inches jounce travel. I'd be happier with more, but will have to investigate. Depends on what size tires I want to run, and so forth.

Looks like the fun is just beginning...

cheers
Jay

http://home.covad.net/~jmaechtlen/

semi-recent pics here