Thread: Question for spring gurus...

Originally Posted by 87County

Yes.. this is right, coils are a torsion bar in a compact form

FWIW - it has been my experience that coils with the same nominal rates can feeel quite different - I've always assumed that the reason is different steels and varying heat treatment (doesn't help much after you order a new set and install them though - if they don't feel a you had hoped)

There shouldn't be any difference at all in feel if the rates are in fact identical on a linear rate spring.

I've known plenty of race drivers that couldn't feel a 50lb change in spring on an open wheeler, or when the anti-roll bar had accidentally been left undone.

A sensitive driver could pick a 15lb difference though, it just depended on the individual (I was one of the sensitive ones )

Originally Posted by rick130

For a given wire diameter the stress should be the same as the wire length is the same, just a slightly tighter coil.

I have the equation for calculating the stress here somewhere.....

And yes, a coil spring is just a torsion bar wound up, works exactly the same.

Do you mean the Rangie springs have a tighter coil.

I would have assumed (I know, never assume ) that the Defender rear has larger dia wire to maintain the pitch. What I do notice is that Land Rover run a much larger pitch than aftermarket springs which I think is interesting.

Originally Posted by Slunnie

Do you mean the Rangie springs have a tighter coil.

I would have assumed (I know, never assume ) that the Defender rear has larger dia wire to maintain the pitch. What I do notice is that Land Rover run a much larger pitch than aftermarket springs which I think is interesting.

Yep, meant that the RRC/Disco has a smaller ID/OD spring.

The pitch is dependent on the wire diameter, and from what I remember Eibach and Hyperco used to say, they would choose the wire diameter to get the smallest block/coil bound height they could (within reason) so you could be right.

Overseas they have a much larger varieties of wire diameters to choose from, particularly the good winders like Eibach (Germany and US), Hyperco (US) and Faulkners (UK)

They also have better spring steels to choose from according to the books I've read, our springs steels aren't considered as good.
Having said that, the old National Springs (I think Monroe bought them out) won some contracts with Mercedes for at least the 190 Series back in the eighties.

They also supplied JRA with 110 and 6x6 springs, I remember my ex-JRA engineer mate saying no other spring manufacturer in Australia at the time could match their fatigue life or even get anywhere near them, yet they all used the same BHP steel.
It was all in the tempering and heat treatment.