[Technical COILER Spring Question]

Ok,

Trev (LR90) and I have been PMming each other a lot (oooeeer) recently about springs (see)

Trev has built his superb calculator program, which measures spring length when compressed by the LR weight etc, which I have then allowed unsprung weight (ie axles) out of the equation.

All seems ok, cept I have come across some spring data which is "Odd" to say the least.

Basically every spring chart I have come across shows.

Number of Coils, sometimes thickness of each, then the free klength etc, THEN the POUNDAGE (ie 170 LBs) and colours (say Red & White).

This then I have shoved through the program, tweaked for unsprung weight etc etc

Now I have ONE Chart which is from a main dealer, its a service bulletin, and talks about exactly the commnet above PLUS one extra column....

LOADAGE.

This shows that whilst a LR Spring may have a poundage, you can have 2 spring with differing LOADGAE ratings...

Ie

NRC 4304 RED & WHITE 170 LBs 17.71 Length 7.00 coils vs

NRC 4234 Green & Yellow 170 LBs 16.2 Length 7.00 coils

RED & WHITE - LOADAGE 1106.06 vs Green and Yellow 978.84

So, I have done some research (also 90 rear springs are 225 LBs and 585...low LOADAGE but high Rating) and think I have some idea, ie the 1st is the amount of force needed to move springing, the second is the amount of weight it can carry without exceeding loading ?.

Ie for the red and whites they both will move at 170 lbs force, but the red and white can carry more weight without exceeding their carrying capacity.

Intersting here is I now have springs some 2+ inches longer on the 90, with 55LBs less Poundage but higher carrying capacity, result is a 20mm lift and better off and on road handling....

Anyone care to expand how the POUNDAGE vs LOADAGE works, and more importantly how can this be calculated into a linear calculation as to final length when fitted to a known weighted LR ?

Nige