Quote:
Originally Posted by sosidge
Since I am not a graduate engineer (although I wish I was!) this goes a little over my head...
I did do a little calculation myself, purely on the surface areas, and it seems to me that a difference in diameter of 0.13mm between piston and body (as you measured on the Kyosho) gives a surface area roughly equivalent to 2x 1.1mm piston holes.
I assume that the calculation for laminar flow is a lot more complex than simply surface area where oil can pass?
So, to ask in complete laymans terms...
Do you think that the pistons you have measured make any significant difference to low-speed damping?
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Sosidge, in layman's terms, I think Arn0 is saying this...
This is all totally theoretical based on some simple maths. It cannot be specific since the actual behaviour of the piston/oil combination depends on many factors like hole size, piston size, hole shape, piston shape, etc.
In order to be specific, you also need to consider the entire behaviour of the car chassis as the mount of weight in the car, the rate of the springs and the suspension layout will change the damping 'value' you get. For example, if you have a lighter spring then it will travel more for the same force input than a heavy spring. If you have more travel you get more damping - the specific value of the damping changes.
This is a well-researched piece of work which if used as Arn0 intended...
Quote:
Originally Posted by Arn0
The point of this chart is to try to provide some reference point for drivers who swap the original shock for other brand or to get some reference point when you try to copy-paste a setup and you do not use the same shocks as the one mentioned on the setup sheet.
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...will allow you to swap from car to car, or damper unit to damper unit, with a little bit more knowledge than you might optherwise have.
Any attempt to use this as a definitive basis for creating the perfect set-up is, of course doomed to failure!!
As any cursory check will show you, the tolerances on piston diameter, hole diameter, any piston edge radius and the cylinder bore itself means that a definitive basis is impossible.
As Roger points out above, the effect of the clearance between piston and cylinder will dwarf any change in hole by a few numbers of drill bit. Great work, Arn0, use with care everyone!!
