v8kid
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| posted on 18/8/08 at 12:05 PM |
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J damper diagram
Anyone got a diagram of a J damper? I was wondering just how heavy they were and what speed the weights are accelerated to.
My old TR8 used to have a mass damper and it was very effective but heavy. These inertors or J dampers should be much lighter and act quicker as they
interact in series? or is it in parallel with the spring.
Anyone agree with me they could herald the death of 3 way dampers?
Only fly in the ointment I can see is they could make the tuned response worse and may be a bit peaky. Also not sure how the reactance? (sorry I only
know the electrical equilivance term could it be momentum?) is varied - do they vary the mass or the gear ratio?
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rpmagazine
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| posted on 18/8/08 at 12:30 PM |
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Would you really want to use one?
A kinetic mass damper would be difficult to tune, react well only to a narrow range of frequencies and AFAIR only works well with a very limited
suspension mvt.
Great for an aero car, but they seem a difficult proposition for a road car.
3 way dampers are straight forward enough, dampers are up to 6/8 way now at the really high end and the Knetic system is very very clever too.
www.racemagazine.com.au
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v8kid
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| posted on 18/8/08 at 12:47 PM |
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Interesting.
Taking the electrical comparison there is no reason why the tuned circuit should have a narrow response. The Q factor in electrical terms is well
known and easily changed.
Dissapointing it is only of use for small displacements. Any idea why?
If it is something inside me says it sounds like a square law coming into effect - mv2?
If these objections could be overcome I'd like 1 or 4 preferably very much indeed please thank you for obvious reasons.
Not the least of which is speed of response of a reactive system making the imperfect, and always imperfect, damping response of any resistive system
look archaic. If it works that is
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Alan B
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| posted on 18/8/08 at 02:42 PM |
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I can't imagine for one minute I'm the only one on here saying "eh, what are they on about?"
Care to enlighten those of us not in the know about J dampers?
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v8kid
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| posted on 18/8/08 at 08:04 PM |
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What makes you thing we know what we are talking about?
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v8kid
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| posted on 18/8/08 at 08:38 PM |
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J dampers are a different type of damper that work by absorbing energy fron the suspension as it rises and releasing it again as it drops.
So they are not really a damper at all as they do not absorb any energy at all. (thats why a damper gets hot and a spring does not)
At this point you may well say - yea that would be a spring then!
Not quite the energy a spring absorbs is dependant on how much you compress it a J damper absorbs energy depending on how fast you compress it
Just as the old fashoned analogue radios used a tuned circuit to only allow the signal they want through using a J damper in conjunction with a spring
can filter out the unwanted frequencies.
Got it?
Electrical engineers get quite excited about this (sad gits) because they know exactly how to manipulate the components in a tuned circuit to get the
response they want.
Trouble id nobody has ever managed to make a J damper ( the mechanical equilivent of an inductance) before.
That is untill McLaren did it and the rest copied ( but did not get fined because F1 is so unbiased against.......).
I can't get my sums to match the reality of what McLaren have achieved and my imaginary versions are bigger and heavier that the photies
I've seen suggest.
Hence anyone got a good photy or diagram so i can try and make a locost one?
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rpmagazine
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| posted on 19/8/08 at 03:44 AM |
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any idea why?...no not that I'd care to put my name to! I had it explained to me by a very clever man who works with such things, but he had to
talk slowly and draw large pictures with crayons!...so in effect I believe I understand some of the principles and was clearly told the ideal
application, but that is about it. There was a good explanation on the Autosport site a short while back.
www.racemagazine.com.au
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v8kid
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| posted on 20/8/08 at 09:24 AM |
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Ha! Found it ta for the tip on the Autosport site I got links from there to the original IEEE papers all is now clear.
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rpmagazine
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| posted on 20/8/08 at 12:10 PM |
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so do you think it is viable?
www.racemagazine.com.au
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