damping effect
Hello,
I am new to the site and I must say thanks to the author for all the usefull articles!
My main interest currently is the suspension, springs and dampers. I obtained a Group A racing suspension for my new race car (BMW E30 M3).
I used the SuspensionCalc I got on this site and I found that natural frequencies are 3,78Hz for the front and 3,88 for the rear. The springs are 180N/mm (around 1000lbs/in) and 160N/mm (around 900lbs/in) and the Bilstein dampers are valved to 350/300 front and 300/250 rear. Valving values are rebound/bump and 350 means 3500N at 250mm/s.
According to calculator, the front and the rear are around 80% critically damped for bump and 93% critically damped for rebound.
I have some questions and would really appreciate the help:
1. why are the springs so hard and why did they use such high natural frequencies? (I read that the usual frequencies for race cars are 2-2.5Hz)
2. although my car will be only for track use, I wont use slicks and my car will be mainly for drifting, will it be too stiff? When drifting it is nice to have a firm car that doesnt roll much, but the grip is also important so that you can accelerate during the drifting.
3. how does overdamping affect the handling and feel? The optimum is said to be 65-70%. What happens when the damping is 100% or even much more?
4. why is often rebound damping higher than bump?
5. if my car will be too stiff and I change the springs for a bit softer (lets say 120N and 95N), and I don't change the valving, then it will be quite overdamped? How will this show and will it be worse than having the original hard springs and correct damping?
Thanks again for the answer!
Best Regards