Do I *need* adjustable spring plates?

[Shaun @ Tru6]

I'll be doing a mild suspension refresh on this 73T Labor Day weekend. It's getting 19/26s and Bilstein struts up front with S calipers, Bilsteins in the back. And then will set the ride height, relatively low.

If I use the protractor method and a little marking/planning, do I need to get the later spring plates?

Anyone have good measurement specs for front and rear ride height for an early car?

Bringing a barn find back to life

[blk911]

Shaun,

adjustable springplates make it a lot easier to corner balance the vehichle, even if you just buy some used factory springplates. Also, if you are doing the work yourself, I hope you are infinately patient. I just did my 79SC and even with protracter and Wil Ferch's guide, be prepared to pull them back out at least three times.

Good luck.

[blk911]

Almost forgot,

Instead of measuring to the fender lip, shoot for being able to place the palm of your hand flat on top of the front tire, perpendicular to the wheel while keeping your wrist flat. For the rear, you need a little rake, back to front for proper aerodynamics.

[Shaun @ Tru6]

Thanks Mike, appreciate the input!

I'm shooting for this stance.

[jkh2cpu]

The adjustable spring plates are nice because they save a lot of time... The time of course is the time needed to tear down, reset, and reassemble.

The way to set the ride height on these machines is to go by the book, which means in the front, find the height of the center of the front wheel, subtract 108 mm, and adjust so that the center of the torsion bar equals the 12.25 inches more or less of the wheel height measurement minus the 4.1 inches or so that 108 mm equals. No one likes math problems and word problems are the pitts, but it's really simple. What I finally did was figure the measurement, and then subtract half the diameter of the torsion bar tube. Using the final measurement, I cut a piece of wood, so all I have to do is adjust to a known quantity. The rear is the same: The distance to the center of the wheel PLUS 12 mm, and measure that distance between ground and the center of the torsion bar.

While you are in there, you might want to consider the quality of the rubber bushings supporting the torsion bars. Rubber will sag, changing the ride height, and possibly changing it enough so that the torsion bar housing rubs on the torsion bar, which is bad because the bar will eventually rust, and then snap. That's not a fun failure mode.

Have fun with your find. It looks like a lot of fun and work.

[911st]

If you are building a race car you should use adjustable spring plates. Adjustable sway bar links to.

If you are building a street car you do not really need them or a formal corner balance.

You should be able to use the angle calculator to get the rears very close to balanced. If one has to be a little higher than the other make it the drivers side and add that amount to the front to.

Rear camber is an important part of the rear ride height so it needs to be set as one deg is like 7-9mm in different ride height. .

Then you should be able to use a "tripod" method to verify the rear is balanced and to dial in the front. This method involves supporting one side by a floor jack at the stock side jack point with the wheels off the car and lowered to same height as the other side which would have the wheels on the ground. Do the ground to torsion bar center lines measurement on the wheel side and make sure they are the same.

Best to do all this with the sway bars disconnected.

Not an expert, just what I would do.