Double-Clutching

[RobbieB]

Is double-clutching completely useless with newer cars (up say 9 years old)? I've heard it is only really beneficial for older cars and hugely high perfomance racing cars. Is the gain noticeable?

[Don]

RobbieB said:

Is double-clutching completely useless with newer cars (up say 9 years old)? I've heard it is only really beneficial for older cars and hugely high perfomance racing cars. Is the gain noticeable?

There is no need to double-declutch when using a modern gearbox with syncromesh. This has been the case for a very long while. Many "classic" cars require the technique. But these are classics.

On the other hand if you have a very worn, very stty gearbox that won't go into gear you may find that double-declutch assists.

[Pugsey]

PLEASE don't start this one again! Instead see 100 plus posts under topic 'Double de-clutching - idiots guide' about four pages back. That will tell you everything you need to know - and a lot you don't! Sorry, techno numpty here so no idea how to do link.

Some one will be along in a minute to clarify whether you actually mean DDCing or rev matching no doubt..................................................

Edited by Pugsey on Wednesday 14th January 11:44

[Don]

Pugsey said:

PLEASE don't start this one again! Instead see 100 plus posts under topic 'Double de-clutching - idiots guide' about four pages back. That will tell you everything you need to know - and a lot you don't! Sorry, techno numpty here so no idea how to do link.

Some one will be along in a minute to clarify whether you actually mean DDCing or rev matching no doubt..................................................

Edited by Pugsey on Wednesday 14th January 11:44

Or blimmin Heel and Toe.

I promised once to start a Wiki on this but never seem to get the time...

[RobbieB]

It would appear I've had a PistonHeads faux pas. Apologies!

[Pugsey]

RobbieB said:

It would appear I've had a PistonHeads faux pas. Apologies!

No, not at all matey. But if you refer to the earlier thread that I highlighted you'll probably see why we groaned when your post came up!

[deeps]

I used to have a Lancia Volumex that was a pig from 3rd to 2nd, that's when I learnt to DDC PDQ! Will have a look at that other thread for a laugh...

[Farmboy UK]

Don't particularly want to start this whole thing up again but I do think even on a modern car its a very useful tool when learning to rev match and drive smoother

My opinion

[GaryST220]

Farmboy UK said:

Don't particularly want to start this whole thing up again but I do think even on a modern car its a very useful tool when learning to rev match and drive smoother

My opinion

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

[John MacK]

GaryST220 said:

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Which parts will be less worn and torn?

[p1esk]

GaryST220 said:

Farmboy UK said:

Don't particularly want to start this whole thing up again but I do think even on a modern car its a very useful tool when learning to rev match and drive smoother

My opinion

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Yes, if it is done well; but if it is done badly the wear and tear may be greater than if DDC had not been used at all.

Best wishes all,
Dave.

[7db]

John MacK said:

GaryST220 said:

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Which parts will be less worn and torn?

The synchromesh rings.

[Farmboy UK]

p1esk said:

GaryST220 said:

Farmboy UK said:

Don't particularly want to start this whole thing up again but I do think even on a modern car its a very useful tool when learning to rev match and drive smoother

My opinion

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Yes, if it is done well; but if it is done badly the wear and tear may be greater than if DDC had not been used at all.

Best wishes all,
Dave.

Why would bad DDC be any worse than any other bad gearchange?

[p1esk]

Farmboy UK said:

p1esk said:

GaryST220 said:

Farmboy UK said:

Don't particularly want to start this whole thing up again but I do think even on a modern car its a very useful tool when learning to rev match and drive smoother

My opinion

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Yes, if it is done well; but if it is done badly the wear and tear may be greater than if DDC had not been used at all.

Best wishes all,
Dave.

Why would bad DDC be any worse than any other bad gearchange?

It might not be in most cases, but if we get the engine speed badly wrong we might end up giving the synchromesh more work to do than if we had left it to make its own adjustment to relative speeds. In any case DDC certainly involves more work for the clutch release mechanism.

Best wishes all,
Dave.

[GaryST220]

7db said:

John MacK said:

GaryST220 said:

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Which parts will be less worn and torn?

The synchromesh rings.

Engine mounts, gearbox and the clutch too!

In normal day to day driving its not needed, but dropping a few gears for maximum power can be very uncomfortable if you don't double clutch.

[7db]

Not sure that those parts are much worse off with a simple accurate rev match, than DDC, but I know the syncro rings are.

Obviously a botched rev-match is a disaster for the drive-train nose to tail.

[m12_nathan]

GaryST220 said:

7db said:

John MacK said:

GaryST220 said:

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Which parts will be less worn and torn?

The synchromesh rings.

Engine mounts, gearbox and the clutch too!

In normal day to day driving its not needed, but dropping a few gears for maximum power can be very uncomfortable if you don't double clutch.

Rev match will sort that. DDC is causing twice the wear on the clutch release mechanism for zero benefit.

[GreenV8S]

Farmboy UK said:

Why would bad DDC be any worse than any other bad gearchange?

It takes twice as many actions so it needs more time, which means it's more likely to be rushed. You only need to mess up the timing of the gear selection versus the clutch a little bit to start grating metal. Meanwhile you're causing twice as much wear and tear on the clutch release mechanism, and the driver is wasting valuable attention and keeping his hands and feet busy for longer than necessary at what is probably a very busy time. If you don't have working synchros then it's necessary. If you do then at best it's harmless; at worst it's a waste of the drivers time and effort, distracts the driver and compromises their ability to control the vehicle while potentially doing more mechanical harm than good. As you can probably tell, I'm all in favour of it.

[7db]

m12_nathan said:

GaryST220 said:

7db said:

John MacK said:

GaryST220 said:

I agree, double declutching is still necessary if you want to reduce the wear and tear on your car.

Which parts will be less worn and torn?

The synchromesh rings.

Engine mounts, gearbox and the clutch too!

In normal day to day driving its not needed, but dropping a few gears for maximum power can be very uncomfortable if you don't double clutch.

Rev match will sort that. DDC is causing twice the wear on the clutch release mechanism for zero benefit.

How does rev matching prevent wear to the synchro rings?

[Farmboy UK]

GreenV8S said:

Farmboy UK said:

Why would bad DDC be any worse than any other bad gearchange?

It takes twice as many actions so it needs more time, which means it's more likely to be rushed. You only need to mess up the timing of the gear selection versus the clutch a little bit to start grating metal. Meanwhile you're causing twice as much wear and tear on the clutch release mechanism, and the driver is wasting valuable attention and keeping his hands and feet busy for longer than necessary at what is probably a very busy time. If you don't have working synchros then it's necessary. If you do then at best it's harmless; at worst it's a waste of the drivers time and effort, distracts the driver and compromises their ability to control the vehicle while potentially doing more mechanical harm than good. As you can probably tell, I'm all in favour of it.

Before I get too much into this I am not a DDC fanboy, I hardly ever use it and I have no worries with most methods of gearchange performed correctly. Right....

For me, the rushing thing does not apply here, I would ONLY use DDC in a situation where there is no rush to change gear. On a rare occasion when I would like to do it I will. I try never to get myself in the situation where I will have to rush my changes but when I do I agree with you that DDC will often be a much longer process and distract the driver.