Still working on suspension studying. It's 4 am & Ive been studying about suspension since last nite at 11 pm. Forgive me if I dont make sense.

Now... I have found a decent link on how to determine Motion Ratios:

http://eaglewoman.simracing.dk/cobra...otionratio.htm

http://eaglewoman.simracing.dk/cobra...tionratio2.htm


A lot of stuff to determine what goes on w/ motion ratio. My question:

Could you please post up your motion ratios if you measured yours or had someone else to do it??

I want to compare what you have w/ other peoples cars. I want to see if it is very different btwn cars of the same gen & so forth.

Thanks,

Pete

 

I (as you can imagine) have no idea what mine are. I *think* that back over a year ago (in the archives that we of course cannot access anymore) RR98ITR had some stuff on this. Bump steer stuff too, it was obviously pretty good since I didn't understand a word of it.

I have some of his camber curve stuff in hardcopy *somewhere* around here too, if that'd help.

 

Yep. Scott put some stuff out. It was for his ITR, I think. I really didn't understand it very well either. I was also thinking @ the time, that I really didn't need to know. I figured that when I could afford (yeah, right! ) some better shocks, the vendor would know what I would need. I hope that is true!

 

Here are Scott's ITR numbers and a bit more info.

Integra ITR motion ratios:
Front: 1.5:1 (for one inch of shaft travel you get 1.5 inches of wheel travel.
Rear: 1.35:1

Wheel rate = (spring rate / (motion ratio squared))

Front wheel rate = spring rate / 2.25

So 400 lb front spring gives a wheel rate of 180,
and a 600 lb spring gives a wheel rate of 270.

Rear wheel rate = spring rate / 1.82

So 250 lb rear spring gives a wheel rate of 140,
and an 800 lb spring gives a wheel rate of 440.

Wheel Frequency CPM = 187.8 square root of wheel rate lbs/in over sprung weight lbs


400F gives wheel rate of 180 & 1.53 cps
600F gives wheel rate of 270 & 1.88 cps
800F gives wheel rate of 355 & 2.15 cps
1000F gives wheel rate of 444 & 2.41 cps
1200F gives wheel rate of 533 & 2.64 cps
1400F gives wheel rate of 622 & 2.85 cps
1600F gives wheel rate of 711 & 3.04 cps

250R gives wheel rate of 140 & 1.7 cps
600R gives wheel rate of 330 & 2.6 cps
800R gives wheel rate of 440 & 3.0 cps
1200R gives wheel rate of 660 & 3.7 cps

Most competition cars' suspension frequencies are around mid to high 2 cycles per second.

You are better using a dial gauge and measuring the wheel movement vs the piston rod movement, too much error in the method on the link you suggested.



[Modified by DB1-R81, 5:51 PM 6/8/2002]

 

Marc: Could you elaborate on the wheel frequency? I became lost in the units.
Also, to determine your own motion ratio, you can measure the shock piston movement relative to the wheel movement? I may do this to determine a good spring rate for my car in the future.

Thanks

 

+ =

 

[e] Sorry bumped the wrong thread.


Modified by sackdz at 1:49 PM 9/25/2003