Hi guys, i'm a bit confused.. so how does this all work and help?
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Hi guys, i'm a bit confused.. so how does this all work and help?
google is your friend.
http://www.motorpoint.com.au/double-clutch.asp
yes and please note:
1) double clutching is not used at any stage while drag racing
2) double clutching is unnecessary in a gearbox with synchros, which includes all modern passenger cars. it's an archaic technique carried over from when gearboxes had no synchros and only used nowadays when downshifting in a heavy vehicle, or a race car with a dog box, or perhaps if your gearbox is shagged
3) rev-matching and heel-toe are still useful and should be learnt
4) do not learn about cars from the fast and the furious
5) please refer to 4) :)
this.Quote:
Originally Posted by lithium
i LOL'DQuote:
Originally Posted by u mad?
yea not hard dude... Practice and learn it... Its good for your f&f mentality...
I do it everywhere. Dont make an awesome habbit police dnt like it lol
Yeh i use it in daily driving... Just makes things more smoother.
i blew the welds on my intake because i was granny shifting and not double clutching like i'm supposed to
I thought double clutching was used during drags? But what's the point of double clutching when you can just brake, then downshift?
save a bit of brakes i guess.
Double clutching is good for 1 thing. Getting into 1st gear while moving at 30km/h when you need the acceleration in an emergency.
LOLQuote:
Originally Posted by lithium
shit man, now me and the mad scientist have to rip apart the block, and replace the....(wait for it).....PISTON RINGS YOU FRIED!
can double clutching be bad for your car?
IF you do it correctly no.Quote:
Originally Posted by .:Thrasher:.
If you do it incorrectly yes.
Same issue as quick shifting.
Doing it properly its awesome as you can go from first to second (whichever gear doesnt matter) in the matter of a second not even..
IF not done properly you run the risk of scratching your gear box n mis-shifting
Quote:
Originally Posted by lithium
Not true - it saves your synchros
i maintain double clutching is UNNECESSARY in a modern gearbox with functioning synchros.Quote:
Originally Posted by Mr_will
why anyone still double clutches on a gearbox with synchros is beyond me. i only ever use it to get into first while moving as mentioned above by Aaron. i suppose you also don't use your brakes because you'll wear out the brake pads? ;)
double clutching is only used on downshifts, therefore it is never used in dragsQuote:
Originally Posted by davidha91
rev-matching is used to smooth a downshift. this is important when you are cornering at the limit, and any jolt in the drivetrain will fling you off the road.
double clutching is rev-matching while clutching out as the shifter passes through neutral. it matches gear speeds inside your gearbox. the main difference you will feel is that the shifter will slide with minimal effort into the lower gear.
the drive-train smoothness of a double clutched downshift will be exactly the same as a correctly rev-matched downshift. therefore double clutching is usually not used in modern passenger cars.
heel-toe is used to rev matching while braking
i hope this all makes sense :)
correct me if i'm wrong, but aren't synchros one of the first things that go in a gearbox that hasnt been thrashed? wouldnt that mean double clutching would save you a bit in the long run?Quote:
Originally Posted by lithium
I thought if a gearbox has never been thrashed the first thing to go would be the clutch? Like lithium said double clutching is unnecessary with cars that have synchros but they do have benefits like saving your synchros. I think with modern cars double clutch is almost pointless I'd say single clutch revmatches are enough.
It's an invaluable tool to have up your sleeve - It's great to know that you'll always have the right gear without the risk of flying through your windscreen, heh.
So what about if you are going lets say 60kms on gear 4 and you are dragging then you downshift to 2 for higher speeds. Is double clutching required?
Why would you be shifting down to 2nd for higher speeds?Quote:
Originally Posted by davidha91
well i'm driving at 60kms on fourth gear and if i downshift to second gear, vtec would kicked him much quicker.Quote:
Originally Posted by braeden
He probably means to downshift to be in the power band. Anyway if you want to downshift double clutch is still not required, like i said before just do single clutch revmatch, meaning blip the throttle before u release clutch and the gear change should be smooth
if you blip before you release the clutch.. your burning (or wateva its called i forgot) the clutch aren't you?
well what I do is use double clutching to downshift on straights when i need to accelerate like overtake or something and heel-toe for corners and sometimes coming to a stop.
its not going to burn your clutch if the clutch is fully in. single clutch revmatch is exactly the same as heel and toe except your not braking, unless you are double clutch heel and toeing.
Not needed 100%, because you can get into 2nd at 60km/h from 4th without double clutching. Of course there will be a bit of wear on your synchros. But say you were going from 2000rpm in 6th gear and wanting to downshift to 2nd gear at 80km/h, then double clutching lets you go from 6th straight into 2nd while minimising wear on the synchros.Quote:
Originally Posted by davidha91
You don't need to double clutch as your gearbox will let you do it. Just saves on a bit of wear.
If you were downshifting from 4th to 2nd, blipping the throttle matches the flywheel speed (engine side) to the clutch speed (gearbox or road side) so that you don't burn the clutch. If you just release the clutch pedal so that the engine speeds up on its own, then that duration where the clutch is pressed down partially causes wear (burning) on the clutch.Quote:
Originally Posted by RtN
You will have more wear/stress on the driveline NOT blipping the throttle. Thats the point of blipping, to rev match the next lower gear.
LOLQuote:
Originally Posted by FDBenni
i can't believe i forgot about the clutch. ahah my bad.
Ah right, I forgot that on OzHonda VTEC means "more speed".Quote:
Originally Posted by FDBenni
:wave:
don't take your foot off the gas pedal. clutch in and downshift to second! your revs will fly up as soon as you clutch in...clutch out and floor it!:thumbsup:Quote:
Originally Posted by davidha91
Isn't that gonna damage your gearbox or clutch? its bad practice to be on the throttle while letting the clutch out, also your going to damage the synchros since revs wont be matched
you guys hav got it all wrong.... Double clutching is when you rip the hand brake up and go right hand down into oncoming traffic its the only way
Quote:
Originally Posted by trism
i lol'd
LOL, now that i must try!Quote:
Originally Posted by migoreng
dun that so many times...Quote:
Originally Posted by davidha91
Always a good smell u smell... haha
did you miss the bit where I said it saves your synchros?Quote:
Originally Posted by lithium
i did a lolQuote:
Originally Posted by trism
i missed the bit where anything in my post was 'Not true'. please tell me what i said that was incorrect.Quote:
Originally Posted by Mr_will
everyone knows that double clutching saves your synchros. my point is that it is an unnecessary technique on a modern gearbox :)
And the 2009 E-hero of the year award goes tooooo...............Quote:
Originally Posted by trism
trism
it is necessary if you want your synchros to last, I don't know if I can break it down for you any furtherQuote:
Originally Posted by lithium
i believe a gearbox treated sympathetically and maintained correctly will last upwards of 250000km before it starts to crunch, with no use of double clutching whatsoever.Quote:
Originally Posted by Mr_will
250000km out of one gearbox is good enough for me. that's ten or twenty years of driving. i guess if you want more you might think it's 'necessary' to double clutch.
look it's not worth trying to argue the semantics of necessary and unnecessary, or what 'wanting to last' means. i agree to disagree with you on this point :)
The benefit of double clutching to save your synchros is quite small compared to looking after it. Your far better off not banging through gears as quick as you can, and shifting in a double movement when driving round normally (with the shifter no the clutch) - Eg. - 1-N, wait half a sec, N-2 which isnt too dissimilar to how you cruise around with a dog box.
Banging through gears is a terrific way to give you a need to change a gearbox or 2, no amount of double clutching or whatever other truck driving technique will ever balance that out.
my understanding is that double clutching was commonplace where driving older vehicles where there was no syncromesh to help the gears engage. Nowadays boxes have synchromesh or synchros that synchronise the gears so as to ensure a smooth transition...
i dont double clutch, but i always rev match... rev matching is probably helping maximise your clutch life more than anything, as well as keeping the gearing down process smooth particularly during spirited driving where you need to keep the car's attitude stable... rather than trying to fight the movement of inertia that comes with gearing down coming into a corner, particularly at high speed and high revs...
what's the difference between double clutching and revmatching? I just revmatch without the double.
Someone also said that you shouldn't exceed 3000rpm with the clutch down (fully) and the gearbox engaged in a gear...
I haven't heard of exceeding 3000rpm being bad, what if for example ur at 3000rpm in 4th and u downshift to 2nd, you would need to revmatch it to around 5000rpm~
oh yeh lol sorry wasn't thinking right... blipping is the idea behind heel-toe .___.
Your both right above. I'm sure you both know that. :thumbsup:
Of course double clutching saves your synchros, your matching speeds on both gears engaging, so your syncros arn't doing any work.
But in turn, thats what synchros designed for. They match speeds of the gears. And I'm sure if your not always smashing through each gear they will last a long long time. No point having synchros if your gonna double clutch all the time.
some one wana record there feet doing this??? never seen it in action
When downshifting:
Eg. 3rd gear > Depress clutch > neutral > release clutch > blip throttle (to match next lower gear) > depress clutch > 2nd gear > release clutch.
Check youtube.Quote:
Originally Posted by xclusive_eg8
watch some japanese racing clips...Quote:
Originally Posted by xclusive_eg8
brake normally, leave your toes on the brake pedal and turn your heel over to the gas pedal.
when you clutch in blip the throttle with your heel at the same time then change gears...
if done right and fast enough your revs will already be up once you let go of the clutch
the syncros don't have to work to bring the revs up, you won't feel the car jerk like when you let go of the clutch fast when downshifting and you car is more balanced when going fast into a corner
:thumbsup:
I think hes asking for a clip of double clutching not heel and toe.
That thing i herd said that you have to:Quote:
Originally Posted by FDBenni
clutch in
shift to neutral
clutch out
-blip-
clutch in
shift to 2
cllutch out
WOT
if you wanna exceeed the 3000 rpm thing..
I rekon it's bs since nobody seemed to acknowledge it
wats blip??
A quick depress (on - off) of the throttle.
I still don't think that's true, because it means that everytime you single clutch revmatch its bad, and that you have to double clutch all the time. I'd say the majority of people that revmatch only single clutch these days, so it can't be all bad.
for the people wanting to watch a vid of double clutch I think this is a good example. Every downshift he does is double clutched, he also double clutch heel and toes.
http://www.youtube.com/watch?v=0j-3xIZK-Bk
i still say double clutch is not necessary with modern cars though.
my thoughts exactly. Why cant you rev whist in gear!
how else could u launch?
You can rev in gear. If the clutch is pressed in, you can rev as much as you want. The only wear in the gearbox would be the thrust bearing (which wears quickly if you like to clutch in and rev often). Double clutching is to allow getting into gear with non-synchro boxes, and can help prolong the synchros a little bit in a synchro-equipped gearbox. Heel toe on the other hand focuses on clutch wear only when releasing clutch after downshifting.Quote:
Originally Posted by curtis265
interesting reading this thread :)
It's just so strange that double clutching and heel-toe has to be used on normal driving on the street. I don't see a need to it except for track when your rev has to be maintained at high point. Why would you want to maintain high rev on the streets? Bring it to the track. don't endanger other road users on the freeway and pedestrians on the streets.
I dont see how revmtaching and heel toe is dangerous on the street. I use it on the street mostly so i dont get that jerky motion when i downshift (your passengers will appreciate it) but also so that the synchros last longer. Its not always to maintain high rev, its to be in the right gear at the right speed.
agree with cymax.
Safe driving is more important on the street than going fast. Slow down when approaching a corner or intersection, then you don't need double clutch/heel-toe/rev match. The rev would be low enough for the lower gear to engage, without killing your synchro/clutch/gearbox.
People are watching too much BMI... even the pro racers in BMI sometimes make mistake (misshift, etc)...
^^ Yeah, that's my whole point. Slow down approaching corner/intersection then you don't need to do those hectic stuff. You rev much when you want quick response from the car. That's my own opinion. Oh well, I believe each individual has their own driving habbits and techniques. My clutch/synchro hasn't given me any problem so far...
each to their own i guess, no matter how low your revs are they aren't going to be matched with the lower gear and therefore get that jerky motion. Revmatching is not that much different from a regular downshift, just 1 extra step which is to blip the throttle. I'd suggest learning it in a empty carpark or something though and not on the street, especially the heel toe where your foot may accidentally slip off the brakes.
In my car, I just need to be gentle when releasing the clutch... no jerky motion.
yeah, you'll get jerky motion when you throw your clutch when down shifting...
Also, if heel-toe is not done correctly can cause the car to have a sudden hard braking when you are twisting your ankle towards the accelerator and therefore causing the car behind you to brake hard.
In conclusion, do whatever you want on the road but drive safe and don't endanger other road users is your responsiblity and top priority...
cheers....
sorry for the noob question but what about just neutraling the car? i understand rev matching and stuff for corners but when you're going in a straight line and slowing down for a red light, would you rev match down all the gears? or do you just downshift to all the gears? can't you just put the car in neutral and brake? wouldn't that not affect your synchros or your clutch at all? this is how my dad taught me to drive and it seems like most old asian people drive like this(family friends/etc)..i didn't even know i had to downshift until my driving instructor told me to so now i downshift(don't quite understand why though, my instructor said it was dangerous or something?) till about gear 2 and then just clutch and brake cos my first gear won't go in unless i have completely stopped.
need this to be cleared up because some of my friends just clutch and brake and laugh at me for down shifting and wasting petrol..
thanks
Its probably a saftey thing. Always keep it in a gear. At least then if you do loose consiousness for any reason then engine/gear braking will slow the car down.
No, just putting it in neutral is dangerous and no one recommends it because in an emergency if you need to accelerate you wont be in gear to do that. Also because putting it in neutral means there is no engine brake at all and you're relying on your brakes. Sometimes I'm lazy and dont downshift but I still make sure I only clutch at the very last second before it starts stalling.
As with any skill, you need to have sufficient practice to be proficient at it before you start doing it on public roads with other traffic. Same as with your driver's license. You get your Ls and then you need to get sufficient hours of road practice time. I agree with you that we should drive safe and responsibly. Hence, anyone who wants to use heeltoe/revmatch/double clutch MUST have sufficient practice and be proficient at it before using it on the street.Quote:
Originally Posted by cymax
If anyone who does heeltoe and brakes super hard unintentionally, then they need more practice and shouldn't be using it on the street yet.
^further to that, once you are proficient, there is absolutely nothing unsafe about it at all... its second nature to me now... but a light flywheel, heavy clutch and solid mounts means sometimes you need to do things to make the ride as smooth as possible
your right in saying that it isn't necesary on the streets, but it does make my driving experinence much more pleasurable, and less jerky lol. ive been heal toeing, rev matching, double clutching since i was 16 on my L's, reason for that is i learnt to drive in my dad's van and dad got sick of me just letting the clutch out as it just jerked around to much so he taught me to rev match and it just went from there, now its second nature i dont even think about doing it, it just happens. you dont have to be hooning along to do it just bliping the throttle fron 2 grand to 3 grand for the lower gear coming up to the roundabout makes things much easier, for me anywayQuote:
Originally Posted by cymax