From: Thomas A. Steahr

The only data I have on hand for aftermarket stuff is from the Mugen brochure. I wonder if anyone has bought this stuff. Their non-adjustable shocks cost $742 for the set! They don't even list a price for their adjustable shock/ spring combo. In any case I took a moment to figure out the damping ratios for the Mugen stuff. This might make a good baseline for people to aim at when setting up their cars given the Mugen reputation. What do you think?

Mugen Adjustable Suspension Kit:   (Stock)
        Compression/Rebound     (Comp /Rebound)
Front:  2.895-2.216/1.857-1.512 (1.965/1.024)
 Rear:  3.623-3.000/2.215-1.915 (2.227/1/039)

Mugen Sports Dampers
(damping ratios based on using stock springs with Sports Dampers)
Front:        2.866/1.569       (1.965/1.024)
 Rear:        3.217/1.782       (2.227/1/039)

As you can see the Mugen stuff offers much better damping and controll of body motions. The Sports Dampers seem to be calibrated to fall inside the range of the adjustable dampers when used with stock springs. These numbers only represent the tendency for the car to bounce or wallow, not how fast the car will settle after hitting a bump. That is mainly described by the natural frequency. Natural frequency is mainly controlled by the spring rate. The higher (stiffer) the spring rate, the higher the natural frequency and the faster the car will respond to bumps. This is also one reason why cars with stiffer springs exhibit faster turn-in response.

It would be an interesting experiment to set up two suspensions that have identical damping ratios but one with stiffer springs (and correspondingly stiffer shocks) then the other. This would allow a comparision of how spring rate effects steering response.

It is interesting to note that with the Sports dampers Mugen increased the rebound damping more than the compression damping (46% increase in compression and 53% increase in rebound for the front damping ratios). I would speculate that this was done to get better vehicle controll without making the ride to harsh over bumps where compression damping would be important. With the adjustables at their stiffest setting they increased compression by 47% and rebound by 81%! I wonder if this is laying the route to high performance handling. Crank up the rebound damping and the car stays solid as a rock.

Copyright 2002, Temple of VTEC