Mann Engineering Coilovers - Inverted

[Captain Snooze]

Originally Posted by Northwest86

I gotta ask but when you Americans say you run 9k springs, do you mean 9kg/mm springs or some other weird imperial imaginary number.

That's not American units, that's metric. Sometimes shown as "9k"; the k is used interchangeably with Newtons and kilograms as in 9 kilograms/mm or 9000 Newtons/mm.
A quick Google would have shown that when the USA is not using metric spring rates they are using pounds/inch.

[Northwest86]

Yeah I always wondered just because I've seen some insanely high spring rates. 9kg is bloody high let alone someone people who run stuff like 15k and higher. Wondered if for some reason they just have weird spring rates or if it was like kg/inch or something weird alone those lines.

[Captain Snooze]

Originally Posted by Northwest86

Yeah I always wondered just because I've seen some insanely high spring rates. 9kg is bloody high let alone someone people who run stuff like 15k and higher.

I used to run 9k/10k springs and given the quality of damping were quite good comfort wise.

Then consider the spring rates needed to run this:

Originally Posted by Rafi@RR-racing

the Element Tuning Time Attack FRS which runs about 1000lbs of rear downforce.

My bold.

Also, given the rear motion ratio of approximately .75 the rate at the rear wheel is a lot less than the given spring rate.