ideal spring rates for coil-overs on Yaris

[Loren]

His generalized calculation is most likely going to give you a general WHEEL rate. Don't forget to include the motion ration in the equation, which means the rear rates need to even higher.

[thebarber]

Originally Posted by Loren

His generalized calculation is most likely going to give you a general WHEEL rate. Don't forget to include the motion ration in the equation, which means the rear rates need to even higher.

ah yes, thats what i forgot to add....so thatd maybe bump up the rears 50lb?

im not honestly GREAT w/ suspension items, but im learning slowly...

[Loren]

Originally Posted by thebarber

ah yes, thats what i forgot to add....so thatd maybe bump up the rears 50lb?

im not honestly GREAT w/ suspension items, but im learning slowly...

To answer that question reliably, someone would have to measure the motion ratio. Easy enough to do with the spring removed and the car on jackstands. Put a jack under the hub and lower it as far as it will go. That's your zero point, take a reference measurement from the ground for both the hub and the lower spring perch. Then raise the hub as high as you can and take both measurements again. Subtract the before and after measurements and compare the result, that's your ratio.

So, for instance, if you had 6" of travel at the hub, and 5.25" of travel at the spring, 5.25/6.00 = .875

Now, if you're looking for a wheel rate of 500#, you'd DIVIDE that by the motion ratio, 500/0.875 = 571

ALL OF THE ABOVE NUMBERS ARE JUST FOR DEMONSTRATION PURPOSES, THEY ARE NOT ACCURATE... THEY'RE NOT EVEN GUESSES. (I know how stuff posted on forums can take on a life of it's own, just thought I'd add that)