On my quest of understanding car set-up, several people have mentioned having shocks dyno tested to check and balance the damping rate for a car/axle set.

Is this something you could measure yourself?

I'm thinking you must be able to mount the shock either way up vertically in a vice, then hang a known weigh (5kg?) from the free end and time it over it's full stroke.

At the very least this should allow you to adjust the damping to be pretty equal for all 4 shocks.

What say you wise people....?

Give Procomp a u2u

Theory is sound, the damping coeffecient of a damper is simply the relationship between force and velocity after all.

The force and times you would be using would be a couple of orders of magnitude different from what the damper would see in use, but I see no reason why it shouldn't give you a good result for matching a pair.

Also if you record the result from a new damper you could in theory check it a few years down the line for deterioration.

[Edited on 13/8/08 by matt_claydon]

As already said, the dyno test for a shock will give you a result in terms of force against velocity. The only problem with this method is that the velocities involved will be way below what is needed to check out a shock.

A 'normal' test speed will be around 500 mm per second. I think you'd need a bit (lots) more than 5kg to hit this sort of speed.

The relationship between force and velocity will not be linear either so the picture and the result will change with speed.

Dynoing your shocks is not something you need to do every day so IMO it's worth going to someone like Matt at Procomp to get it done right.

Having said that, you can see if a shock has failed using this method so it's not without merit.

Thanks for the feedback chaps.

I have discussed with Matt before, but as ever was looking for a locost/diy method of doing it.

As said it would provide a reasonable way of checking the general condition of the damper.

Not being a matematical kind of guy, what sort of weight would you need to apply to geta reasonable travel rate for testing...50, 100, 500kg?

Race Tech magazine ISSUE 9
Damper Dyno - a DIY approach

Will take a look!