[bridsanaeds]

so what is meant by double clutch?? i though it means shifting the stick without pressing the pedal.

It's called double clutch because you use the pedal twice. The clutch pedal is the third pedal present only in a manual transmission vehicle. Pedals from the left -> Clutch -> Brake -> Accelerator. You can use the rev matching methods used in double-clutching to avoid using the clutch entirely, but that technique is not called double-clutching, it also has even less use than full double clutching (except if your clutch packs it in, then it's handy to help you get the car to a garage and get it fixed).

[PilotVertolet]

I tired changing gear wityhou using my clutch ttoday and I can safely say i sounded like a right ****.

but I did however try it with the clutch pedal half depressed and lowe and behold it glided between the gears quite nicely.

but i wouldnt recomend it

[actioliGalm]

I dont really see the point, maybe Im missing something, I change gear at the right time for my car depending on what I want to do, go fast or relax.

I basicly just learned my car inside and out, can shift really quickly if needed too so i dont really see the point in risking breaking something.

[soipguibbom]

I'd never head of double clutching before but I understand how it works now. I'm not going to bother trying it though - no need for me to really in normal everyday driving.

Heel and toe looks good too but I don't think I'd be able to do that unless I was in a sports or race car (legs are too long to twist like that!).

[MartZubok]

I tired changing gear wityhou using my clutch ttoday and I can safely say i sounded like a right ****.

but I did however try it with the clutch pedal half depressed and lowe and behold it glided between the gears quite nicely.

but i wouldnt recomend it

you have to get the rev's just right to do it, and even then, some gearboxes just dont like it.

it works best if your driving an old, peice of **** car, then you dont need the clutch at all (except for starting)

[bridsanaeds]

I dont really see the point, maybe Im missing something, I change gear at the right time for my car depending on what I want to do, go fast or relax.

I basicly just learned my car inside and out, can shift really quickly if needed too so i dont really see the point in risking breaking something.

The chances of breaking something are really no greater than when shifting the "regular" way.

I think it has use in cars with a high power output or particularly wide rev range. With a wide rev range, a downshift might be a difference of 3000rpm or more. It takes a while for synchros to catch up with that difference, double clutching can match it faster. For a powerful car, smoothing a downshift can be of great benefit in preventing an upset in the balance of the car. For example, coming around a corner and you need to downshift for a bit more power going up a hill. Doing a straight shift and letting the synchro (and possibly clutch slip) catch up with the rev change for you could see a loss of traction and a skid. Double clutch, or even just rev match with a single clutch and you can completely avoid any jolt at all.

[spklnraz]

I tired changing gear wityhou using my clutch ttoday and I can safely say i sounded like a right ****.

but I did however try it with the clutch pedal half depressed and lowe and behold it glided between the gears quite nicely.

but i wouldnt recomend it

thats probably because the clutch engage/disengage spot usually isnt right at the floor, it was with my old s-10 though because the master cylinder was shot... not fun

on my old 944, it was very high though, i barely had to hit the clutch to go through the gears (it was a brand new clutch)

[ananciguinter]

So if i understand correctly can double clutching when downshifting prevent my car from Feeling as if something hit the engine when i downshit to a lower gear at high speed through straight shift.

if this is the case then i can do it like for example (3rd gear ----> cluch ----> netural ------> cluch ------> 2nd Gear) ???

so if this the case then is there any benfit for this when upshifting???

also when using double cluch method i described above what could go wrong in the car????

[Aminkaoo]

so erm might I ask how many gear boxes you have been through in your life time !

i've killed one by ham handedly pushing a transmission into 2nd too hard in an 1983 pontiac T1000. think vauxhall chevette. 1.6L and 60 hp. that transmission worked okay after putting a new shift fork in it. i learned how to clutchless shift when the clutch slave cylinder went out on the toyota. that transmission was still around when that truck went on to the great wrecking yard in the sky. incedentially, may semi drivers clutchless shift on all btu the first few shifts.

[lkastonidwedsrer]

Pardon?

Change gears without a clutch? ... how?

An automatic has two clutches usually, a manual has one clutch.

Theres also CVT, sequential etc types of transmission too, but ... they have a clutch of some form, whether its where u press the pedal with your leg or it does it all for you.

Erm, an automatic doesnt usually have two clutches...who told you that ?

Instead of a clutch and automatic has a torque convertor which connects the engine to the transmission.

Semi autos such as the DSG gearbox utilises 2 clutches controlled automatically, this is not a proper automatic.

[PilotVertolet]

Erm, an automatic doesnt usually have two clutches...who told you that ?

Instead of a clutch and automatic has a torque convertor which connects the engine to the transmission.

Semi autos such as the DSG gearbox utilises 2 clutches controlled automatically, this is not a proper automatic.

the normally have whats known as a fluid flywheel

kinda like a fan in a case full of oil.

also automatics use epicyclic gearing

[lkastonidwedsrer]

the normally have whats known as a fluid flywheel

kinda like a fan in a case full of oil.

also automatics use epicyclic gearing

Thats a fluid coupling which is no longer used in modern automatic road cars which use a locking torque convertor (neither a fluid coupling or a torque convertor can be considered to be clutches), and what you are showing at the bottom is a planetary gearset which is inside the transmission and is used to create drive ratios.
The planetary gearset has various bands and clutches for it to work, but thats nothing to do with the clutch system thats found at the flywheel of a manual transmission.

[PilotVertolet]

Thats a fluid coupling which is no longer used in modern automatic road cars which use a locking torque convertor (neither a fluid coupling or a torque convertor can be considered to be clutches), and what you are showing at the bottom is a planetary gearset which is inside the transmission and is used to create drive ratios.
The planetary gearset has various bands and clutches for it to work, but thats nothing to do with the clutch system thats found at the flywheel of a manual transmission.

nerd !

[soajerwaradaY]

Semi autos such as the DSG gearbox utilises 2 clutches controlled automatically, this is not a proper automatic.

I thought the DSG is the only one which has 2 clutches?

[lkastonidwedsrer]

I thought the DSG is the only one which has 2 clutches?

The DSG is made by Borgwarner who license the design to Audi/VW etc. Im not 100% sure but i think there are other transmission manufacturers who make a similar unit.

[bridsanaeds]

So if i understand correctly can double clutching when downshifting prevent my car from Feeling as if something hit the engine when i downshit to a lower gear at high speed through straight shift.

That's exactly what it can do. Though you don't really have to double clutch to alleviate most of that, rev-matching alone can make all the difference.

if this is the case then i can do it like for example (3rd gear ----> cluch ----> netural ------> cluch ------> 2nd Gear) ???

Exactly. An example where its effect is even more obvious would be shifting from 4th through to 2nd.

so if this the case then is there any benfit for this when upshifting???

Not much really, the only advantage to it in a synchro-mesh box is that the revs will drop a little quicker. Say you've just revved the guts out of 2nd to get onto the highway, then want to drop into top gear, a double-clutch upshift would help make things a little smoother, but just leaving the clutch in for a while longer would have pretty much the same effect.

also when using double cluch method i described above what could go wrong in the car????

You'll know if you're doing something wrong. The only way you'll damage the car is by doing it wrong, but you run that risk with normal shifting anyway. Things like mis-timing the clutch pedal could mean you grind the gears. Maybe if you're in neutral and get the throttle wrong you could over-rev the engine

If you get good at it and do it all the time, you'll actually put less wear on the cars components. Although you'll be pushing the clutch pedal twice as much (ok, maybe you'd wear out the pedal hinge quicker or something, no big deal), the clutch itself will spend less time slipping, meaning it won't wear as quickly. Smoothing everything out also means there's less general wear on the gears and drive train. It also preserves the lifespan of the synchro-mesh because it's getting far less use.

[ananciguinter]

"Snixtor"

Thank you dude very much for all this info

finally i understand it correctly.