Thread: Rear Springs
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Old 30th March 2006, 19:38
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Cool Mk II Calculation

Oh Bother (or words to that effect) Gonna try again. No pictures this time.

Distance between spring plates at full travel 6.75" (actualy irelavent)
Distance between spring plates when drive shaft is parallel to ground = 5.25"
At this point the distance between the bump stops is 2" giving 2*16.5/12.5 about 2.6" max travel at the wheel before the bump stops. (More than my Mini used to have)


Static force at spring plates = 440*16.5/12.5 = 580 lb (See previous post for how I arrived at 440)

If we use a 7" free length spring.
Compression to acheive 5.25" = 1.75"
Spring rate therefore = 580/1.75 = 332 lb/in

If we use an 8" free length spring
Compression to acheive 5.25" = 2.75"
Spring rate therefore = 580/2.75 = 210 lb/in

I think the problem with using a softer spring is the suspension may run out of travel when carrying a heavier load (Heavy passenger for example)

What does Black-Cat think - Patrick do you know how to contact this guy?

How about all the interested parties chipping in for a prototype set of springs - anyone game for that? Could be a better idea than getting 3 or four sets that are wrong...
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