Standard springs

[craig]

John, what length springs did you opt for and whats the benefit of fitting the helper spring over say a longer main spring and simply winding it down slightly?

Craig

[alackofspeed]

Craig,

To get the car to sit at about 150mm you need to compress the damper rod about 50% of the way in (for arguments sake). If you set the spring to zero pre-load, with the damper rod fully extended, and the coil adjustable collar just touching the spring, with a 300lb spring there isn't enough weight in the car to compress the spring to achieve the ride height.

If you back off the adjustment collar, then when the front suspension is unloaded the spring will rattle freely on the shock, and it's not impossible for the bottom coil seat to fall off. The helper spring allows the adjustable coil seat to be wound out to acheive the desired ride height, but because the helper spring is 4" long and rated at 4lb it will extend once the main srping has run out of length, and maintain a little bit of pressure on the spring / coil seats, and keep thing in place.

I've got 9" front springs.

edit: having cleaned up my Marlin supplied front springs, I've discovered they are 170 lb 10".

[eaa53]

Picking up again about springs, I wanted to know what I got!
One spring reads ‘10 300’ so that’s easy (rear = 10inch 300lb rating).
The front ones are unmarked and a lot less stiff.

I can use the calculation to see how close my measuring can get with the formula and the 10 300 then use the same measuring techniques to estimate the front ones.

Then I can choose what I need. That will come later from a bag of bits in the back of the garage or from a spring supplier.

This formula helps to work out what you got, the web site does it better if you are not into the math’s and calculators.

This assists you to work out approx. what you have in your hand, steady boys… If you are offered a set of springs and are unsure of its rating or if drop them all on the floor and mix them all up…

By the way the coil measurement is the dimension under the paint…. It does not include the paint thickness in its calculation.


FORMULA:

spring rate =

modulus of spring steel X wire diameter4
----------------------------------------
8 X number of active coils X mean coil diameter3

(modulus of spring steel = 11,250,000 pounds/inch2 = 78,500 newtons/millimeter2)


The site that sorts it all out for you....

http://guzzitech.com/springrate.html


Enjoy

eaa53

[limpabit]

These are the ones I went for.

http://www.rallydesign.co.uk/product...oducts_id=9357

But would probably go for the 9" ones now.

[craig]

I have today taken my shocks and springs off and my spring rates are as follows:

Front 8" 200lb

Rear 9" 450lb

Craig