Inboard springs on trailing arm to coilover spring rates.

[chrisroberts]

Hi,

does anyone know of a calculation or ever worked out a way of converting spring rates used inboard on the trailing arm, to running the equivalent as a coilover, if that makes sense....?

Thanks

[stevesingo]

It's best to work with wheel rates so you have a constant comparison.

To calculate the wheel rate (WR) from spring rate (SR) you need the motion ratio (MR)

Front 0.921
Rear 0.64 (stock)
Rear 1.04 (Coil Over)

WR= MR*MR*SR

Example

200lb/in spring on the front

0.921*0.921*200= 169.64

200lb/in spring on the rear (stock) 0.64*0.64*200= 81.92
200lb/in spring on the rear (coil over) 1.04*1.04*200= 216.32

If you wanted to work out what a coil over rate would be for a given stock spring use the following in excel

=(0.64*0.64*SR)/(1.04*1.04)

[stevesingo]

Double post