AlpineFD

there has been multiple users who measured the motion ratio to be 0.70 front and 0.667 rear on s2000.

it's abit odd you end up with a much different number.

twohoos

Yes, it's odd. Shortly after SB posted this, I did some fairly careful measurements on my own and came up with numbers that, while a little lower than those early estimates, are still pretty consistent (basically mid/high 0.6's for dampers, 0.5ish for bars). I've been meaning to write it all up but it's actually turned out to be much (much!) more involved than the springs research I did, and I still have a lot of questions about un-modeled (and even unmeasurable!) effects that could be very significant.

Anyway, I'll try to make some progress on it over the next several weeks, but fair warning: short of a multimillion-dollar kinematics and compliance (K&C) lab, I'm a little doubtful that we'll ever get a clear picture of this car's MR characteristics.

B serious

My plan was to confirm this also.

The 1.73:1 (.578) rear MR leaves me with like +200LB of unsprung weight to match an assumed ~650LB corner weight.

My 447LB spring compressed 1.61" (41mm). Figure that the air spring supports ~50LB. That means my rear shock/spring is supporting 771LB. Full tank, empty car. Bushings clocked. Car driven to settle suspension.

My car is like 100ish LB lighter than stock. Most of that weight is missing from the back of the car. No soft top. No spare. Single exhaust. Recaro PP's.

771/1.73 leaves me with ~446LB of sprung weight.

An MR of .578 works if my rear corner weight is significantly lighter than I'm thinking? Maybe it is.

In the spring, I'll throw an empty stock rear shock on there and measure. I think the stock rear shock's pre-bumpstop travel is like 3.x". So that should give me a good enough measurement window to discern if the value is closer to 0.667 vs 0.578.

AlpineFD

Just noticed the manual that came with the HKS HYPER IV SP coilover kit list the leverage ratio as 1.50 front, and 1.49 rear.
which translates to motion ratio of front 0.667 and rear 0.67

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