'80 Triumph Tr-7

[STINEY]

Coil spring mounts are on the lower arm, again very similar to the FOX mustang.

Upper cup is on the unibody of course. The front end geometry is also very similar as well.

Any advice from the venerable Sir Holmes will be much appreciated!



Here is a shot of both upper and lower arm mount locations.

[Bob Holmes]

My advice is to take measurements from each suspension set up, plot them and compare.

[STINEY]

With the length and angle of those top arms, they are darn near functioning as a panhard bar.

Would pinion angle change more or less with longer, less parrellel upper arms? I'm envisioning more...

[milner351]

are you going to minitub this thing? probably not much room for that.

[STINEY]

Nope.....it has flares. Going out instead of in.

[Bob Holmes]

That's why its called a quadra-bind. The angled upper and lower control arms are also supposed to locate the rear axle. If you were to add a panhard, you'd need to make at least one set of the arms parallel.

I think buying or building a torque arm and using a panhard would be light years better.

[Deaf Bob]

Yep.

With the length and angle of those top arms, they are darn near functioning as a panhard bar.

Would pinion angle change more or less with longer, less parrellel upper arms? I'm envisioning more...

Know this... Shorter lowers brings the pinion angle up.. Which is what we want when the car bends in a derby.. Some guys lengthen the uppers to get the same effect.. Seems a paradox, thinking about it.. .. We do the lowers because we can just make one cut, overlap and weld the wee outa it.. Doing the uppers requires adding metal.. They are usually gradual widing from one end to other while lowers are same width ..

[STINEY]

Yep, I got all the pinion angle setup tuning in my head.......that is, for GM and Ford's versions. (Which are nearly identical)

But look real close at this one, particularly the upper mounting point.

Its darn near on top of the lower mounting point. And WAY behind the lower point.
I
nstead of being inside the unibody frame rail, it is literally UNDER it. The outer point is swung WAY to the outside.

Far more angle (as compared to the lower link) than the domestic quadra-bind setups.

Seems that during suspension cycling there would be a lot more pinion angle change, at least more than normally changes in the domestic setups.

Just making mental notes for the future. Note #1, be sure to triple check pinion angle change.

[milner351]

as rudimentary as this sounds it maybe a good exercise to use popsicle sticks at scaled lengths with holes and pins on a piece of cardboard to work this out a bit before you start cutting any metal. Yea - I'm sure it could be done in cad - but if you don't know the software already - graph paper and popsicle sticks get the win for efficiency!

[STINEY]

I like it John.......in fact, guess what this weekends science project with the boys is going to be?

Working scale model with popsicles sticks. Have to eat the popsicles first!

Great idea, thanks!

[milner351]

I was originally thinking in 2D using graph paper to help the scaling on the cardboard - but with a wood dowel rod to simulate the axle - you might be able to build a full blown 3D scale model of this thing - with "adjustable links" to figure out what's what.

[STINEY]

News Flash.

Just talked with Mr HemiJoel Sr, and he thought of something else to share with me.

He swears he saw this car (or an exact duplicate) on the cover of a magazine. Might have been HOTROD, might have been some other car magazine.

Sometime between 1985 and 2000.

Anyone remember something like this? Maybe narrow the search a bit?

[Bob Holmes]

My advice is to take measurements from each suspension set up, plot them and compare.

Somebody said this, somebody else should do this.

Without doing this you won't be able to check your anti-squat, your instant centers, etc., etc., etc.,

[Bob Holmes]

I want to see pictures of someone crawling around on the floor with plumb bobs, string, tape and sharpies. Make sure the floor is flat, and the car is properly positioned.

[SuperBuickGuy]

News Flash.

Just talked with Mr HemiJoel Sr, and he thought of something else to share with me.

He swears he saw this car (or an exact duplicate) on the cover of a magazine. Might have been HOTROD, might have been some other car magazine.

Sometime between 1985 and 2000.

Anyone remember something like this? Maybe narrow the search a bit?

Yep, I saw it