Ride hight?

[Zithlord]

Car 1971S. I am reasemblying the rear suspension. I have a angle of 5 degrees on the car( rear up) and the radius arm hanging free at 25 degrees. This gives an actual 30 degrees on a free hanging radius arm. When the car is of the jack I meassure 64cm fender at center of wheel to the floor. My torsion bars is 23mm and I belive they are original. What surprices me is that in most litterature the radius arm hanging free should be 35-36 degrees! I tried that but then I had 66cm from fender lip to floor. Its now back to 64cm and when the seats , gas tank, muffler etc is back on the car I will be at the recomended 63,5(25inches) in the rear. Any toughts on this?

Thanks
John

[Flieger]

Weight will make a difference.

http://rennlight.com/cgi-bin/spring.cgi

[Zithlord]

I tried that calculator, it gave the same 35 degree result, 66cm fender to floor.

The car lacks approx 120kg in parts, I added the weight and the car dropped from 64,3 to 63,3 in the rear. Thats with the 30 degree free hanging radius arm, and not with the recomended 35 degrees. Something dos not add up.... Could the 23mm torsion bars be stiffer than original? They look like the standard type to me...

John

[Zithlord]

Pictures of 64cm floor to fender and 66cm floor to fender(at wheel center) This is when the car lacks 120kg in parts and fluids. If I add 120kg, (myselves and my doughter) the rear lowers approx 1cm compared to picture 1 and 2(64 to 63cm).

John

[Flieger]

Did you have any numbers written on the spring plate before the restoration? I believe that is the factory setting for them with the rockers level. If your car is stock I would try that. Seems it was 31 degrees or something like that.

What size tires and wheels do you have? Smaller wheels with a given aspect ratio will have a smaller rolling radius and cause the ride height to look higher.

I am confused about where you are taking the measurements and whether the car is on the ground or not with those measurements.

The factory specs are torsion bar axis to wheel hub, this takes all the other variables out of the equation.

If you have the factory rubber bushings, their friction and added spring rate mean that you need to drive the car around a bumpy road or else jump up and down on the rocker in order to settle the car before it can be corner balanced or have the ride heights dialed in. Could this be your problem? Gas charged Bilstein dampers also have added spring rate due to that gas charge and can lift the rear an inch or so. That is another likely culprit.

[Mr9146]

30-32 degrees should net you around 24 1/2" - 25" ride height with stock bars. (19/22)

With 24mm rear bars I shoot for 29-30 degrees and with 26mm bars it's about 26-28.

It really all depends on what kind of weight you'll be putting into the car, but if you get 31 degrees at the spring plate you will probably be okay.

[Zithlord]

Thanks Marco and Flieger
I have now set both sides to 30 degrees. The fender to floor height is 62,5 cm, and it looks very good with a clearence of approx 2 cm between top of wheel and fender lip seen directly from the side.
The wheels are Fuchs 14 inch with 185/70/14 tires. When finnished the car will have deep six in front and deep 7(7R) in the rear. And yes, I did bounce the car up and down many times between the adjustments to settle the hight. I also rolled it back and forth. The shocks are brand new Koni classics. The radius arm bushings are elephant racing standard rubber, much like the originals. When I took messurements the car was on stands, thats why I added the degrees of angle messured in the door opening to the free hanging radius arm(approx 5+25=30degrees) with the rear of the car higher than the front(5degrees). I think I will settle with this result for now and see if I will have to adjust when assembly is finnished.
Thanks
John