Discussion
Does anyone know how (or if) a dual friction clutch works? Or to be more exacting, how it's any better than a 'normal' organic facing on both sides?
To me what kills an organic clutch is when it has been slipped excessively, (too much torque for it to handle), which heats the material to such a state it cannot recover, either that or it just slips under power anyhow making it useless. If that is the case, how does that ^^ make things any better? Surely the organic face will suffer and fail.
It kind of implies that there is a different percentage of 'slippage' (for want of a better word) from the FW to the pressure plate.
To me what kills an organic clutch is when it has been slipped excessively, (too much torque for it to handle), which heats the material to such a state it cannot recover, either that or it just slips under power anyhow making it useless. If that is the case, how does that ^^ make things any better? Surely the organic face will suffer and fail.
It kind of implies that there is a different percentage of 'slippage' (for want of a better word) from the FW to the pressure plate.
I've never driven one, but as far as I've read it's basically a segmented plate on one side and a solid plate on the other. The segmented plate has a higher peak torque capacity so presumably helps prevent the clutch plate creeping under load, while the solid plate has a more progressive bite as the clutch is engaged. Whether it's actually beneficial or just marketing hype I have no idea. Is it supposed to be an alternative to a multiplate clutch?
PhillipM said:
227bhp said:
That makes no sense 
Why not?You have two interfaces:
1. Friction disc to FW
2. Friction disc to clutch cover.
So you are implying that there is more torque applied to one than the other? If there is then this thing will work, but how?
Well, since the pressure plate and FW are bolted together, it doesn't matter.
So if you slip the clutch a bit as the friction coefficient of the organic is dropping off from the heat, the friction of the sintered will probably be rising into it's operating range.
Of course, that still means you have the crap engagement of the sintered side and the fade of the organic all in one handy package
TL:DR get a full face Kevlar one.
So if you slip the clutch a bit as the friction coefficient of the organic is dropping off from the heat, the friction of the sintered will probably be rising into it's operating range.
Of course, that still means you have the crap engagement of the sintered side and the fade of the organic all in one handy package
TL:DR get a full face Kevlar one.
PhillipM said:
Well, since the pressure plate and FW are bolted together, it doesn't matter.
So if you slip the clutch a bit as the friction coefficient of the organic is dropping off from the heat, the friction of the sintered will probably be rising into it's operating range.
Of course, that still means you have the crap engagement of the sintered side and the fade of the organic all in one handy package
TL:DR get a full face Kevlar one.
When you slip the clutch (or it slips when overloaded) you would have thought both sides of the friction disc will slip equally, so it will always pick on the organic facing and make that slip - it will still slip overall. I can see maybe there is an advantage from heat, you would expect a standard FW could absorb more heat than the cover.So if you slip the clutch a bit as the friction coefficient of the organic is dropping off from the heat, the friction of the sintered will probably be rising into it's operating range.
Of course, that still means you have the crap engagement of the sintered side and the fade of the organic all in one handy package
TL:DR get a full face Kevlar one.
Kevlar? Yes I was going on to that one next
Or a better question...what sort of job does your clutch have to do that you're looking at this sort of thing ?
It was centreforce that started that style of clutch, along with silly weights on the diaphragm fingers.
TBH I've never heard of any particularly good reports about their product though and they've been around for a long time. The latter surprises me because of the former lol
Is it a fast road, race, drag, how much power, how much grip, etc etc etc ?
I've always seen the dual friction as a bit of a gimmick, although how clutches behave is sometimes strange.
It was centreforce that started that style of clutch, along with silly weights on the diaphragm fingers.
TBH I've never heard of any particularly good reports about their product though and they've been around for a long time. The latter surprises me because of the former lol
Is it a fast road, race, drag, how much power, how much grip, etc etc etc ?
I've always seen the dual friction as a bit of a gimmick, although how clutches behave is sometimes strange.
Which side does the segmented friction surface point to? To the flywheel or the pressure plate? I can't see how the clutch can transmit any more torque than whatever the surface with the lowest coefficient of friction can take however if the grippy side is against the flywheel I suppose it would help ensure all the slippage and wear takes place on the pressure plate which is easily replaceable. Other than that it seems pointless.
Both friction materials are under the same clamping force so the max torque the clutch can take will be determined by whichever material has the best friction properties.
The only benefit I can see is that the organic surface may start to grip at a lower clamping force and give a smoother and more progressive engagement which is sadly lacking in 'performance' clutches.
Steve
The only benefit I can see is that the organic surface may start to grip at a lower clamping force and give a smoother and more progressive engagement which is sadly lacking in 'performance' clutches.
Steve
If the image is a true representation (as opposed to 'library picture') then the pads you see go to the clutch cover.
I'm trying to cut through some of the BS really, what some companies are doing is taking standard clutch covers, spraying them gaudy colours and selling them as uprated or 'Motorsport'.
There are some mods in the package like different friction materials, which will cope with the heat better and grip more effectively, but what they don't seem to be doing is increasing the clamp load which is ultimately what you should do I believe.
Another 'mod' i've seen is they have started putting grooves in the clutch cover like brake discs.
I suppose every bit adds a small % which adds up to a total of X%, much like engine tuning.
But what does kevlar bring to the party? More grip and less effected by the heat probably, but any downsides? There is a long bedding in period with it for some reason.
I'm trying to cut through some of the BS really, what some companies are doing is taking standard clutch covers, spraying them gaudy colours and selling them as uprated or 'Motorsport'.
There are some mods in the package like different friction materials, which will cope with the heat better and grip more effectively, but what they don't seem to be doing is increasing the clamp load which is ultimately what you should do I believe.
Another 'mod' i've seen is they have started putting grooves in the clutch cover like brake discs.
I suppose every bit adds a small % which adds up to a total of X%, much like engine tuning.
But what does kevlar bring to the party? More grip and less effected by the heat probably, but any downsides? There is a long bedding in period with it for some reason.
Edited by 227bhp on Saturday 25th February 14:37
Mignon said:
Steve_D said:
the max torque the clutch can take will be determined by whichever material has the best friction properties.Steve
It will be determined by whichever material has the worst (lowest) friction properties.GreenV8S said:
It will be determined by the sum of the friction properties on both sides i.e. flywheel to driven plate and pressure plate to driven plate.
You're quite right. I had myself thinking for a while it could slip on one side or the other only but of course it has to be both at the same time.227bhp said:
If the image is a true representation (as opposed to 'library picture') then the pads you see go to the clutch cover.
I'm trying to cut through some of the BS really, what some companies are doing is taking standard clutch covers, spraying them gaudy colours and selling them as uprated or 'Motorsport'.
There are some mods in the package like different friction materials, which will cope with the heat better and grip more effectively, but what they don't seem to be doing is increasing the clamp load which is ultimately what you should do I believe.
Another 'mod' i've seen is they have started putting grooves in the clutch cover like brake discs.
I suppose every bit adds a small % which adds up to a total of X%, much like engine tuning.
But what does kevlar bring to the party? More grip and less effected by the heat probably, but any downsides? There is a long bedding in period with it for some reason.
There are many materials that could be used...but again what needs to be used depends on what the clutch is required to do for each individual user.I'm trying to cut through some of the BS really, what some companies are doing is taking standard clutch covers, spraying them gaudy colours and selling them as uprated or 'Motorsport'.
There are some mods in the package like different friction materials, which will cope with the heat better and grip more effectively, but what they don't seem to be doing is increasing the clamp load which is ultimately what you should do I believe.
Another 'mod' i've seen is they have started putting grooves in the clutch cover like brake discs.
I suppose every bit adds a small % which adds up to a total of X%, much like engine tuning.
But what does kevlar bring to the party? More grip and less effected by the heat probably, but any downsides? There is a long bedding in period with it for some reason.
Edited by 227bhp on Saturday 25th February 14:37
No different than various brake pads really.
227bhp said:
But what does kevlar bring to the party? More grip and less effected by the heat probably, but any downsides? There is a long bedding in period with it for some reason.
Well assuming by looking at the dual friction plates above you were wanting good engagement/driveability of a normal organic compound combined with the torque handling that the sintered copper/metallic pucks give...a full face Kevlar will generally give you that.They are very wear resistant, very forgiving/low abrasion on the pressure plate and flywheel surfaces (which is why they take a while to bed in), generally have a chunk more torque handling than the cheaper organics with smooth engagement and more heat tolerance.
They won't handle the torque a proper metallic or ceramic clutch will but then a lot of the cheap paddle plates these days are made using a great big bag of pucks they buy premade from the cheapest seller China and rivet onto a disc rather than specced for the use - they're not exactly top-spec materials unless you're going over to AP, Tilton, Helix, etc.
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