Motion ratio for S13?

[Def]

Does anybody know the motion ratio for a stock geometry S13 suspension? I want to calculate the wheel rate based on different spring rates, but can't find this info.

Also, what are the stock S13 sway bar diameters? Has anybody tried just a larger front bar with a significantly higher springrate in the rear to improve traction out back when getting on the power on corner exit? A thicker swaybar will pick the inside rear wheel up on corner exit, so going with a thinner bar and beefier springs to get the right wheel rate is usually better.

TIA

[Def]

Anybody? Does anyone on this board even know what a motion ratio is???

Ok, Wheel Rate = Spring Rate X Motion Ratio

The Motion ratio = Length of suspension arm to spring mounting point(for struts this is where the damper mounts to the suspension arm) / Total length of suspension arm(all the way to the hub)

The higher the motion ratio, the less leverage the wheel has to compress the spring.

[Q45tech]

The 240, 300, J, and Q all share a similiar rear design: The angle of the rear coil and the mount location means an 84% [spring rate x 0.84] correction for the rear springs. The sway bar mounts to the mid point of the lower arm so correct bar rate by dividing by 4 for wheel rate.........a 20 mm hollow rear Q bar is approximately 38-40 lb/in [wheel rate] without the rubber bushings.The 123 inch pound Q rear oem springs have a 103 inch pound wheel rate.

One must correct for the rubber seats and bushings in the 1st inch of roll.

The theory is fine but you really need to use scales to measure the actual.

Any rear sway bar that is more than 50% of the total rear stiffness will be problematic. The mistake most make is not considering the additional rebound shock stiffness required with sway bars.

[Def]

Thanks for the reply. So a motion ratio for the rear is 0.84. Hmmmm, any idea what the front is? Most likely higher. I'm just trying to get an idea of what spring rates one would have to run to get approximate wheel rates to be equal front and rear.

As for the rubber springseats and bushings, one doesn't necessarily need to "correct" for them. Just keep in mind what they will do to the time response of your MBK(mass, damper spring) system. They're like tender springs all over.