Rear Springs won't fit!!!!!!!!!!!

[Peter Cobbold]

Thank you all.

I have the early brackets with 1 notch on the inner and 2 notches on the outer brackets, my car is a 1970 CP car.

From what I have read the trailing arms are the early style TA's, (the ribs are not reinforced), but consider me a junior TR member.

I do not understand however how these would impact spring selection, is there something I should be aware of when ordering springs?

I have not decided on ride hight yet, but defenitely want a slighty higher springrate, will study the other posts around this topic.

Thanks,

Waldi

Waldi,

It will help decide if you know the rate of your existing springs. That can be calculated here:

http://www.engineersedge.com/spring_comp_calc_k.htm

Note that the wire diameter ( d ) needs to be measured accurately, ideally with a micrometer.

Peter

[Waldi]

Peter,

thank you.

Last time I did this exercise is some 35 years ago. I converted my measurements to English units, this is an English forum after all .

Here are my numbers, they can be used by anyone on the forum to verify their own calculations:

d= wire diameter= 14.25 mm = 0.5610 inch (like you said, small variations have big impact on outcome, so remove all dirt, paint, rust before measuring).

D= mean diameter = 88 mm = 3,4646 inch

n= number of active coils = 9

G=modulus of rigidity =11.000.000 psi (this number can be used for all springs in our cars, as long as they are from carbon or low allow alloy steel. It does not vary much for the various grades of carbon based steel, and the type of heat treatment or material hardness does not influence this number)

 

The outcome in my case is a spring rate of 365.3 pound/inch

So this is close to what the Moss catalogue would call "standard" (@ 350 pound/inch)

I bought the car as a non-driver, so have no idea if I like the current spring rate, but I plan to go for the uprated springs (390 pound/inch) and see if I like them, probably I do.

 

Regards,

Waldi