I am getting ready to fab an upper (3rd) link for my rear suspension. The photo shows my hi tech simulation firmware modeling the side view of my rear solid axle suspension. Front of car to the left, rear to the right. The lower arm geometry is stock Ford Mustang. The upper arm is for a 3rd link (I repeat - 3 link not 4). The pivot point for the axle end of the 3rd link is a given - it already exists on the axle. So that leaves the chassis end of the 3rd link where I need to decide where to locate.
On my little cardboard mockup I have located it's forward pivot point as shown in the photo because this is where the pinion angle is the most stable during axle travel up and down. Any other reasonable locations that I tried caused much more change in pinion angle. Is it OK to use this geometry? Or are there handling problems this creates (like instant center stuff that I don't understand)?
Don49
Dork
5/9/19 3:57 p.m.
It looks very similar to what I did on my F Production Turner and it worked very well. The key ( I think) is the least impact on the pinion angle. My set up used a panhard rod also.
Pinion angle curve is practically the most important factor in any 3/4-link design. Looks alright to me, similar to many factory setups. I want to see what NONACK says, he's designed and built custom 4-link setups before.
A little bumpity before I start welding. So far I've got 2 votes (3 if you count me) that pinion angle stability is a good goal. Nobody is objecting (yet) to the upper link being angled upward.
With the 3rd link inclined upward it will behave well under hard braking. It won't be great under hard acceleration unless it's inclined down some. What is your intended use for the vehicle? My limited knowledge of 3/4 links says the lower links should be level and the upper one(s) inclined downward. You're in the realm of instant centers and anti-squat and a bunch of other detailed stuff.
2GRX7
Reader
5/14/19 10:22 a.m.
^Can you find any diagrams of this kind of suspension system? I can't find any pics that are still up that show me how the whole thing works.
2GRX7
Reader
5/14/19 11:33 a.m.
GameboyRMH said:
^Can you find any diagrams of this kind of suspension system? I can't find any pics that are still up that show me how the whole thing works.
This is the best i've seen-an exploded view of an FB RX-7 set-up
Of course, this set-up would introduce binding, so please imagine with Spherical bearings in place of bushings. Also, that support bar triangulating the lower links may get in the way of adjustability.
^Interesting, sort of an upside-down 3-link.
