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Old 08-14-2015, 09:35 AM   #8671
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Default Calculating Damping Ratio

Please forgive me if this seems like a question that only an engineer would ask, but has anyone calculated what the damping ratio is for different A and B distances? My car has the black, sealed dampers (which I believe contain 500cst?).

It would be handy if the damping ratio remained essentially unchanged by adjusting the A distance only (at least for relatively small changes), and considering how well the car is engineered, it wouldn't surprise me if this were the case.

Does anyone have a graph or spreadsheet they can share showing damping ratio vs A and B distances?
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Old 08-14-2015, 10:16 AM   #8672
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The manual (available online) has curves for the overall suspension stiffness for different A and B values. Not sure if this what you are looking for but its probably the closest thing you will find.

The older dampers (marked D6) had something like 60k oil in them, but the construction was totally different to the new D2 style rebuildable dampers. Low speed damping is similar to D6 with 500cst in D2s, but hi speed is very different due to the different damper design
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Old 08-14-2015, 10:59 AM   #8673
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Originally Posted by howardcano View Post
It would be handy if the damping ratio remained essentially unchanged by adjusting the A distance only (at least for relatively small changes), and considering how well the car is engineered, it wouldn't surprise me if this were the case.

Does anyone have a graph or spreadsheet they can share showing damping ratio vs A and B distances?
I find the setup sheets quite handy for quick changes. They actually calculate the gF/mm on the fly as you change the A and B distances on the sheet.
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Awesomatix EP Touring Car (A700 Shaft Drive)-springrates.jpg  
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Old 08-14-2015, 11:34 AM   #8674
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I find the setup sheets quite handy for quick changes. They actually calculate the gF/mm on the fly as you change the A and B distances on the sheet.
I have seen, and have been using, the spring rate charts. But they give no information on the damping ratio. Not that it will kill me, since no other cars give that information either. It's just to satisfy my curiousity.
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Old 08-14-2015, 11:35 AM   #8675
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Originally Posted by geeunit1014 View Post
The older dampers (marked D6) had something like 60k oil in them, but the construction was totally different to the new D2 style rebuildable dampers. Low speed damping is similar to D6 with 500cst in D2s, but hi speed is very different due to the different damper design
My dampers have a "3" stamped on the outside. Would these also be the old construction? If I recall correctly from reading this thread, the old style used nested cylinders that worked the fluid in shear, while the new ones have vanes and orifices-- is that right?

Do the new dampers have more or less damping at high velocities, given equal damping at low velocities?
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Old 08-14-2015, 12:03 PM   #8676
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Originally Posted by howardcano View Post
My dampers have a "3" stamped on the outside. Would these also be the old construction? If I recall correctly from reading this thread, the old style used nested cylinders that worked the fluid in shear, while the new ones have vanes and orifices-- is that right?

Do the new dampers have more or less damping at high velocities, given equal damping at low velocities?
The answer below my post
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Old 08-14-2015, 12:25 PM   #8677
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Originally Posted by howardcano View Post
My dampers have a "3" stamped on the outside. Would these also be the old construction? If I recall correctly from reading this thread, the old style used nested cylinders that worked the fluid in shear, while the new ones have vanes and orifices-- is that right?

Do the new dampers have more or less damping at high velocities, given equal damping at low velocities?
What you said is correct. The D3's IIRC were like 30% softer than 6s. Although i did have some 3s that were actually 6s, but idk if i got those b/c hanulec would know i know whats up and didnt want to freak any customers out, not sure if they were released into the wild.

The old dampers in hi speed (bumps) would shear badly and lose damping. The new dampers pack in hi speed like typical tc shocks do.
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Old 08-14-2015, 04:17 PM   #8678
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I got some stories about the #3 dampers and the hot Florida sun of 2013 roar asphalt nats... Anyway.

#3 are pretty much too light for anything but maybe slow motors indoors. I'd recommend #6 or the d2.x instead (d2.1 preferred )
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Old 08-14-2015, 07:13 PM   #8679
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when it comes to the rfg how much movement would there be? same as the front? looking at the diagram and attaching all 4 screws from the am-82 to the am81 and am44-1 this would not allow it to move because the complete assemble is attached to the mm2 and chassis, thus creating one solid piece
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Old 08-14-2015, 07:31 PM   #8680
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when it comes to the rfg how much movement would there be? same as the front? looking at the diagram and attaching all 4 screws from the am-82 to the am81 and am44-1 this would not allow it to move because the complete assemble is attached to the mm2 and chassis, thus creating one solid piece
The AM73-1 + AM81 complex should be stiff, and the RFG "should" float just like the FFG does. I'll know by tomorrow morning how the production assembly falls together...
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Old 08-14-2015, 08:03 PM   #8681
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Originally Posted by hanulec View Post
The AM73-1 + AM81 complex should be stiff, and the RFG "should" float just like the FFG does. I'll know by tomorrow morning how the production assembly falls together...

thanks please let us know, any youtube videos of the rfg movement yet?
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Old 08-14-2015, 08:24 PM   #8682
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How essential are the diff covers for an outdoor asphalt track, specifically the lower ones, FFG seems to move a lot nicer without it
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Old 08-15-2015, 01:12 AM   #8683
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How essential are the diff covers for an outdoor asphalt track, specifically the lower ones, FFG seems to move a lot nicer without it
I don't think they are essential at all. At best they will extend how long you can go without maintaining the bevel gears. I run on an outdoor asphalt track as well. I used them for a while to keep the gears as clean as possible, but stopped running them since I shimmed my drivetrain up. I have yet to run into any problems, and the car looks way cooler without them on Am I the only one that imagines if Terminators had RC cars, they would look like this?

Anyway... Clean the teeth and use some type of dry lube on them between race days and you will be fine. For what its worth, every time I see the car of some high end Awesomatix driver they never have the diff covers on
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Old 08-15-2015, 02:54 AM   #8684
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Originally Posted by hanulec View Post
I got some stories about the #3 dampers and the hot Florida sun of 2013 roar asphalt nats... Anyway.

#3 are pretty much too light for anything but maybe slow motors indoors. I'd recommend #6 or the d2.x instead (d2.1 preferred )
No problems so far. The track temperature has been above 130F both times I have run the car outdoors. But then again, I'm not entirely sure that the dampers haven't been modified by the previous owner, and I've been using the soft springs.

However, I did find that the handling gets a little funky if the set screw that holds the SPR02 lever arm into the shock loosens and falls out.

EDIT: The dampers are actually L6/R6; I was looking at the wrong side, apparently. I have no idea what the "3" that is stamped on the other end means.
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Old 08-15-2015, 04:43 AM   #8685
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Does anyone have a good way of holding the SPR01 onto the little pin on the inboard end, so it doesn't pop off while installing the spring/damper assembly in the car? I'm not against using a little dab of glue, but maybe there is a more elegant solution.
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Last edited by howardcano; 08-15-2015 at 06:03 AM. Reason: Changed "shock/damper" to spring/damper".
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