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Inboard springs on trailing arm to coilover spring rates.

Posted: Fri Oct 16, 2015 10:43 am
by 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

Re: Inboard springs on trailing arm to coilover spring rates

Posted: Tue Feb 16, 2016 8:25 am
by 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)

Re: Inboard springs on trailing arm to coilover spring rates

Posted: Tue Feb 16, 2016 8:25 am
by stevesingo
Double post