I spent some time searching NAM and couldn't find an answer to my question... Google search reveals a thread on motoringunderground, stating the R53 has a rear motion ratio of .87:1.

Has anyone verified this calculation on the R56?

 

Go to MINIUSA.com, select LEARN ==> COLOR, FEATURES & SPECS. Select a model, then click on PRICING & FULL FEATURES LIST. Scroll down to Transmission and it lists all the gear ratios.

 

Huh?

 

If you followed my instructions, this is what you should see:

 

BTW, that number doesn't make sense to me.

I Googled, and this site lists 3.81 for an R53: http://www.vehix.com/car-reviews/200...specifications

 

At least we can find a definition of "motion ratio" so as not to be confused by other things like gear ratios.

http://en.wikipedia.org/wiki/Motion_ratio

 

OK, my bad. I confused it with gear ratio.

 

James,

The motion ratio is obviously very close to 1:1 due to the supension design. This is usually only an issue with rocker or bellcrank suspensions where the ratios can be 2:1, etc.

If you are trying to calculate extremely precise wheel rates, I think using .9 for your MR will be very close.

DOC

 

Based on the placement of the lower damper mount, on the back-side of the suspension knuckle, it does indeed make sense that the ratio is higher... closer to 1:1...

I am indeed trying to calculate wheel rates and natural frequencies. I collected measurements myself on a previous track car, which verified commonly accepted ratios for that chassis. I was hoping someone had done the dirty work for me on the R56

 

I apologize for not being more forthcoming in the original post... yes I was referring to motion/lever-arm ratios in regards to the suspension... not gear ratios... hence the post in being in Suspension subforum.

 

The Mini suspension world is not quite as advanced as you might think, which is a shame for such a great platform. It would be great if you posted your results for what spring rates you end up with for your chosen natural frequencies.

I did jot down in my notes .875 for the R53, but as with anything you read on the internet, it's worth double checking. It's easy enough to measure yourself, too. I don't know if I measured that myself or saw it posted somewhere....I did not need to get too advanced with my suspension design in the end.

- Andrew

 

Was still working on obtaining the rear motion ratio of the R55.
However; need to get off my lazy but and properly measure and reference it.

- Erik