liam.mccaffrey
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| posted on 21/4/08 at 01:50 PM |
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Horizontal Coilovers
I remember reading a long time ago that mounting coilovers horizontally prevents them from functioning correctly.
I don't mean reducing their effectiveness when they are mounted outboard and inclined. But specifically when they are used inboard.
Do they have to be special shocks?
Thanks
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v8kid
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| posted on 21/4/08 at 02:05 PM |
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Some shocks have an airgap at the top and if you use them horizontally or upside dowm the oil foams and is less effective.
If you are buying new phone the facrory and tell them to top it up - they did it for me no charge.
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MikeCapon
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| posted on 21/4/08 at 02:06 PM |
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Hi Liam,
The only type of shock that will not work in a position other than near vertical (body at the bottom) is the cheapo type of unit with a quantity of
air together with the oil. These shocks prime themselves in use and the air ends up between the inner and outer body tubes where it causes no problem.
In any other position the air will end up all over the place preventing the shock from working correctly.
Types of shocks that will be OK include twin tube gas shocks (the gas is in a cell between the inner and outer body tubes)or gas charged monotubes
with either a floating piston or remote reservoir. Ask the supplier or look on their website for clues.
One wway of identifying the cheapo air oil units is to shake them next to your ear!! If you hear liquid slosshing around then odds on it's an
air/oil unit.
www.shock-factory.co.uk
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tegwin
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| posted on 21/4/08 at 02:07 PM |
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I guess some shocks might not like being run on their sides....what with the dampers being oil based....
But I wouldnt imagine any of the branded shocks would have an issue...
The other thing to consider is the valving.....If its mounted inboard you can get away with more delicate valving on the dampers...
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www.verticalhorizonsmedia.tv
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liam.mccaffrey
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| posted on 21/4/08 at 02:14 PM |
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FYI
I have AVO twin tube coilovers, so hopefully not an issue
[Edited on 21/4/08 by liam.mccaffrey]
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nick205
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| posted on 21/4/08 at 02:18 PM |
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Best to ask Avo to confirm before commiting to a design IMHO
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MikeCapon
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| posted on 21/4/08 at 02:32 PM |
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As far as I am aware AVO's are a twin tube design with a gas cell. If so they will be OK.
To make sure take off the spring from one unit and set the adjuster to minimum. With the body at the bottom hold the bottom eye in a vice and push the
rod in. Then pull the rod out. You should feel a smooth resistance in both directions. Much more when pulling the rod out.
Then turn the unit upside down, hold the other eye in the vice and repeat. The resistance should be identical. In the case of the cheapo air/oil units
there will be parts of the movements without resistance (this is when the air gets to where it shouldn't be).
www.shock-factory.co.uk
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liam.mccaffrey
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| posted on 21/4/08 at 02:41 PM |
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cool thanks for that Ill try and let you know, though I have done this with one of them and it was smooth and consistant resistance in both
directions. Can't remember if one way was more or less though
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MikeCapon
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| posted on 21/4/08 at 03:01 PM |
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Looking at AVO's website their main product appears still to be a twin tube gas unit. Your findings would tend to confirm that.
As far as the differing resistances on opening/closing the shock go this can depend on the speed that the rod is pushed/pulled. Rebound (opening) is
usually around 3 times the resistance of closing (compression).
www.shock-factory.co.uk
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liam.mccaffrey
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| posted on 21/4/08 at 03:32 PM |
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with the body at the bottom the rebound is about 2x the resistance of the bump
with the body at the top the rebound is about 3x the resisatance of the bump
also the bump feels as though there may be air in there. first half inch no resistance then loud gurgling all the way.
this happens only intermitantly though somtimes its as it should be
I will try one of the other tonight, maybe this shocker is knackered
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procomp
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| posted on 21/4/08 at 07:01 PM |
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Hi your basic AVO has no GAS in it at all. It is purely an oil filled damper. The same as GAZ and PROTECH. And having tested them upside down on the
dyno even with them fully full of oil. They allow air past the seal and air-ate after a few hours of use. The only way to use your GAZ AVO PROTECH is
upright ish. and the right way up. However BILSTEINS as used on the caterhams and NITRONS use oil/gas and can be run upside down ect.
Cheers Matt
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MikeCapon
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| posted on 22/4/08 at 12:11 PM |
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Hello Matt,
Thanks for your advice. I'm a bit confused though, as although I have never stripped an AVO or a GAZ I have dyno tested them and they behaved the
same way as the old yellow coke bottle shaped SPAX units which, as far as I am aware they are pretty much copied from.
Having stripped the old SPAXs they have a polythene gas cell inside, thus permitting the shock to be filled completely with oil leaving the gas cell
submerged in the oil between the pressure tube and the body tube. In fact, if you completely fill a shock with oil, ie no air or gas, then closing the
unit is impossible. In fact if you try hard enough the body explodes. Ask me how I know this!
The gas in these cells is not under pressure. It is Sulphur Hexaflouride and due to the design of this type of twin tube unit the cell is simply
compressed as the rod enters the body and then returns to it's original volume as the rod comes out again. The same principle is used on some
Koni units and I have used it very succesfully on thousands of bike shocks. A few people are confused by the fact that the rod does not return to full
open on it's own like the high pressure gas units and in the past this has lead to a few people imagining that either the shock has
"lost" it's gas or is an air/oil emulsion unit like a lot of cheapo car shocks.
Here's a cutaway of an old design where you can see the gas cell on the left between the pressure tube and the body tube.
[img][/img]
www.shock-factory.co.uk
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