3 link for my 65 falcon

[Bryce]

Since i officially started building the parts i decided to start a thread. This way i can keep track of my progress.

I ordered my currie 9".

and welded on the upper brackets for the top link. Pic attached.

next will be to make the Watts link and coilover bracket that attaches to the car.

Oh.... and i plan on not taking the car of the road for more than a weekend at a time as i build this. So it will be running leaf springs with clamp on pads with the new 9" housing. and just for fun i will be lowering the car 2" in the back with the leafs and i am going to build a set of traction bars.

so i will run the leafs with a watts link at some point.

then build the upper link to car bracket.

I have not decided if im going to run a sway bar yet. any input. I think i can easily make future changes to accomodate this.

[Norm Peterson]

When you get around to building the chassis-side bracket for the upper, don't under-estimate the load in the upper link (think wheel hop under acceleration and fatigue effects). I'd guess plan on adding some longitudinal structure to pick up the bracket loads.


Norm

[Bryce]

thank you Norm.

My plan was to grab floor and the frame rails (if you can call them that, HAHA)

Norm, one question for you. what is the length of the new mustang upper link.

Mine will be short around 12" but that keeps it out of the rear seat. i still think its longer than the new mustang. and look how well they can perform.

[Norm Peterson]

The upper link in the S197 Mustang is about 8.5" long, measured pin to pin.


See also post # 14 here (the link lengths are from on-car measurements I made that should be within 1/16" or so.


Norm

[Bryce]

thanks norm.

as always you have great information.

[LowBuckX]

8.5 Thats way short. Why would they have done that? Id at least double that.

[Bryce]

yep thats a short link. with minimal suspension travel and a short wheelbase car it can work without a crazy amount of pinion angle change.

[Norm Peterson]

8.5 Thats way short. Why would they have done that? Id at least double that.

Actually, it's a bit better than GM's A/G body 4-links, which are only about 7.75" long in side view projection.

I suspect three related reasons - packaging space under the floorpan, rear seat room and minimizing the likelihood that the upper link (or part of it) would become a spear in a rear-end collision. For a race car or serious autocross car neither of the interior considerations would matter and you'd likely modify the floorpan so you could fit what you wanted.

From the rest of the measurements I took, the rate of pinion angle change looks to be around 1°/inch of bump travel. I'll assume that that's kind of high (it certainly would be if you were looking at camber gain in a car built to corner). But at least the anti-squat is fairly stable over the first two inches of bump travel even though the IC moves rearward quite a bit.


Norm

[Mean 69]

"lore" has it that the orginal plan for the Mustang was to have IRS, but the bean counters ruled against it. Becuase a large part of the factory package was already defined, the suspension had to be designed around packaging considerations, and in a very short amount of time. I believe this to be true as I have heard it from multiple sources close to the action at Ford. Don't blame the suspension team at Ford, blame the accountants. Funny, the earlier Cobra Mustangs had IRS (best if done well), and a Mac-strut front (generally not the desired approach). Now, it's a stick axle 3-Link (good if done well), and an SLA front (best if done well). The new Camaros went the other way around.....

Interesting data on the migrations, Norm. I would have guessed that it would be larger (pinion angle change in particular), dependent upon the lower link length as well obviously.

But yes, if you were to clean sheet a design, I'd say that error on the long side is a lot better for kinematics/suspension performance. Just make sure you sharpen your pencil on the load requirements and material/strength side of things.

Fun stuff, you will come out significantly more educated after going through the project, best of luck.

Mark

[Bryce]

yes at one point the mustang had a IRS designed for it. but the lack of performance improvement and the high cost stopped production of this setup. the reason for lack of performance was due to the lack of a good tire.

[Bryce]

update:

fully welded upper housing link and painted in black hammertone, one of the toughest rattle can paints i have used.

[Norm Peterson]

Interesting data on the migrations, Norm. I would have guessed that it would be larger (pinion angle change in particular), dependent upon the lower link length as well obviously.

It's progressive, being more like 2°/in once you pass 2" bump.


Norm

[Bryce]

so i got some better measurments and dimension. the lower links will be 23" long. they will be adjustable from flat to 5* inclination and the upper mount will be 14" and 8* decline and adjustable all the way to flat. this will give me adjsutment from 0 antisquat to 150%. but only a 40" IC. is that too short?

[Norm Peterson]

150% is likely more than you'll ever need. What is the SVSA length (IC) at 100% A/S?


Norm

[Bryce]

58" at 100%
and 136" at 54%

[JRouche]

update:

fully welded upper housing link and painted in black hammertone, one of the toughest rattle can paints i have used.

Hey!! Looking good. You have some solid welds and that bracket is stout. I LIKE!! Good to see you posted a fire watch for post welding too. He (or she) looks more alert then some of the guys I have worked with. Keep the pics rolling. I am a fanatic for looking at the build pics. JR

[Bryce]

I wish i could take credit for the welds but i outsourced them but my guy did it for $20. Yep, my shop dog, mollie, is always in the garage with me.

i will keep pics coming for sure.

[novaderrik]

that is one big dog to be able to carry that rear end housing around in it's mouth like that. Clifford would be a better name..

[Bryce]

haha, thanks.

she is only 60lbs. but still thinks she is a lap dog.

I was on vacation in Mammoth last weekend doing some hiking. so updates will happen this week

I was thinking about buying a fays2 watts link to save time. but still contemplating. It would only be pieces as i already have the watts axle mounts and i would get aluminum rodends and bars.

[JRouche]

I was thinking about buying a fays2 watts link to save time. but still contemplating. It would only be pieces as i already have the watts axle mounts and i would get aluminum rodends and bars.

Thats pretty close to what I did. Jim is cool about selling the parts you need. Aluminum rod ends? Or just the bars? Cant wait to see the pics. JR