Double Declutching, why double declutch?? (1 Viewer)

[cb205]

What I'm about to say has probably already been said, but im too lazy to read all fo it.
Double clutching is mainly a technique used when the gearbox does not have synchromesh.
As for double-clutching in 'modern' vehicles, it's really just personal preferance.
I learnt to drive in a truck (thats being a country kid for ya) I took alot of those habits to driving a car, so I do it all the time.
As for wear-and-tear, if its done correctly the extra wear on the clutch is minimal.

hope this helps.
cheers
steve

 

[Zozo6969]

Double declutch is also done in modern day cars to reduce wear on the synchros as well as the clutch, as when the revs of the drivetrain and the engine are near equal, u pretty much just drop the clutch straight away with pretty much no slippage = reduced friction = less heat = less wear on the clutch

 

[Pace_T]

Double declutch is also done in modern day cars to reduce wear on the synchros as well as the clutch, as when the revs of the drivetrain and the engine are near equal, u pretty much just drop the clutch straight away with pretty much no slippage = reduced friction = less heat = less wear on the clutch

wen i use 2 slowly take out the clutch after down shifting the car wouldnt downshift smoothly because hte revs drop down way too fast. i naturally figured out myself to hit the accelerator a bit while the clutch is fully in before i start letting it out and i can take it out really quick as the revs are matched. when i hit the accelerator i dont bother taking the clutch out to do it, i hit it when the clutch is still fully in.
in other cars i can just release the clutch slowly n it doesnt slip, but in my car (the newest of the 1s i compared) i have to hit the accelerator (blip?) so its perfectly smooth

 

[Azamakumar]

downshifting is for noobs. If you really need to downshift, then the engines already running low enough to downshift smoothly. If your car does jerk when you downshift, then you are indeed spastic, and should be driving auto. If you're stopping at a traffic light or something, dont downshift, just clutch and brake fool, downshifting is for children. accelerating slightly and releasing the clutch slowly helps a shitload when your shifting, makes it as smooth as a babys behind.

 

[Dumsum]

^ umm... braking is for stopping, not for slowing down... that's what I always thought (ie downshift to slow down)

 

[Zozo6969]

downshifting is for noobs. If you really need to downshift, then the engines already running low enough to downshift smoothly. If your car does jerk when you downshift, then you are indeed spastic, and should be driving auto. If you're stopping at a traffic light or something, dont downshift, just clutch and brake fool, downshifting is for children. accelerating slightly and releasing the clutch slowly helps a shitload when your shifting, makes it as smooth as a babys behind.

Mate, u r always supposed to keep the car in gear, no matter how slow u r going, and should only put the clutch in about 5 metres before u completely stop.

Releasing the clutch slowly is quite stupid and only novice drivers would do this. this is called slipping it out, and creates friction between the flywheel and clutch plate, causing higher temperatures, and will eventually wear out the clutch. a more experienced driver will be able to pretty much lift their foot off the clutch during gearchanges and have absolutely no jerking of the car at all, and during takeoff, their foot would be on the clutch for no greater than about 2 seconds.

And how can u downchange and lift ur foot off the clutch straight away with no jerking??? double declutch.

 

[petar13]

Mate, u r always supposed to keep the car in gear, no matter how slow u r going, and should only put the clutch in about 5 metres before u completely stop.

What a waste of petrol. Do you mean to seriously say that you take a car from 5th down to 1st before actually stopping at traffic lights?

 

[Zozo6969]

no i mean that u just keep it in fifth and only dump the clutch in when the engine is revving really low, like at like idle just b4 it stalls. u should never coast down a street in neutral or with the clutch in.

 

[Riet]

Revving while the clutch is in is bad practise as it damages both the synchros and the clutch.

 

[Riet]

What a waste of petrol. Do you mean to seriously say that you take a car from 5th down to 1st before actually stopping at traffic lights?

Keeping the car in gear doesn't use more petrol since fuel consumption depends alot on throttle position, much more so than revs. Engine braking is good because you don't wear at your pads or clutch quite as quickly. If you don't want to keep it in 5th you should shift into neutral and let the clutch out when you brake.

 

[nick1048]

EDIT: <quote thread starter>


You know your clutch sequence reads like a DDR pattern this then this then this then this then this etc.

 

[Daffyflyer]

Revving while the clutch is in is bad practise as it damages both the synchros and the clutch.

Assuming you get the revs correct surely it would be better for the syncros?

And the reason I double clutch is so as not to slow the driving wheels when downshifting.
If I downshift my race car without double clutching it will sometimes lock the rear wheels on dirt... quite scary..

Besides, it just seems to feel smoother.

And my uncle who has done club level motorsport/rallies etc for 20yrs or so reckons it is better for the gearbox (dunno about the clutch though)

 

[Riet]

The synchros are one thing, riding the clutch damages err.. the clutch... As for locking the wheels when downshifting that's probably because this race car has a dogbox rather than a road car transmission, you lock the wheels when you let the clutch out too quickly. Double clutching isn't the same as revving with the clutch in.

 

[Daffyflyer]

OK, I don't really know enough to argue this one, but im willing to belive you are right.

And no, it does not have a dog box, but the synchro on 2nd is rooted (You actually do need to double clutch to get it into 2nd at any real speed)


And agreed, the wheel locking is not really about double clutching, more just rev matching

You've got me intrested now, I dont know that much about gearboxes, im more of an engine nut!