Double clutching

[ian]

So tell me exactly how you "double clutch" and what are the benefits? is it worth double clutching when you drag someone off the lights? :?

[madgrk]

When about to change gear, clutch in to neutral and let the revs rise then clutch into your next gear.. I believe it is like this..

[fusion_VTi]

i always thought it was down changeing?? when ur comin up to a corner i usually just put in clutch, put it in neutral then rev it a bit then put in clutch and change down the gear, i dunnno just what my old man tought me but who who knows,lol

[madgrk]

Pretty sure its up gears. You dont need to do it if your car is relatively new anyway. Unless your synchros are about to die on ya hehe :D

[Weq]

"granny shifting instead of soubling clutching like you should"
its the worse line from f&f, totally BS. The quickest shift involves not clutching at all!

[muli]

friends dads truck you have to double clutch when downshifting, its due to worn out synchro's on the gears. its a pain in the arse, basically pushing the cluth in twice, first time to put it into neutral then second time to select gear.

[MKI4EVA]

just rent the video and learn.

[A'PEXi]

umm there was a thread in ff forum about it, try doing a search there :D fusion vti i think thats heel & toe :D

[poid]

fusion VTi has it right...heel & toe is doing that while braking

Use it while downshifting, when upshifting do it normally, or flat shift if you hate your car or have a nice ECU that has a flatshift program :)

[SIKCVC]

riends dads truck you have to double clutch when downshifting, its due to worn out synchro's on the gears. its a pain in the arse, basically pushing the cluth in twice, first time to put it into neutral then second time to select gear.

And thats the ONLY time you would need to use it in a veihcle where the syncros are ****ed(this includes missing a gear and having to reset it) or not even syncro gear box... if you use it any other time your an idiot and deserve to be shot!!!

Theres a technique that people often confuse with doubling the clutch and its called Heal and toe... its onyl really usful on a track or hard driving... ie Keeping the revs up while under BRAKES(and yes i mean foot on the brake, it shouldn't leave the brake) to do this while having your foot on the brake you clutch in, shift out of gear, Blip the throttle to keep the revs up enough for the next gear down, put it into gear and (if your good enough at it) dump the clutch(otherwise release the clutch at a quick rate). I made a post about it on MCCR... I'll find it and link it if anyone is intrested in the different braking techniques.

[wynode]

I said what double clutching is in another thread.....try searching

[CIVIC-R]

the fastest gear change would be a flat change... where ur foot never comes off the accelerator the whole quater mile! :)

[alan]

heal toe not only keeps revs up
main reason for it is to control the car's weight distribution when downshifting and cornering

wouldn't want the car to suddenly jump cuos of downshifting while cornering...

[SPEEDCORE]

heal toe not only keeps revs up
main reason for it is to control the car's weight distribution when downshifting and cornering

wouldn't want the car to suddenly jump cuos of downshifting while cornering...

Correct! Matching the revs will transfer less shock though the drivetrain making it more controlled and predictable while cornering.

[wynode]

Not to mention less wear on your synchros and gearbox :)

[SIKCVC]

the order in which you move the gears is important too... Its not too great for the syncros if you put it into gear before matching the revs, doesn't take long at all to pick this technique up although most people do strugle with it in day to day driving (since it serves no purpose :P) But I have found myself using it and needing it quite a few ocasions... good thing to learn also good fun to learn.

[geo41e]

umm...heel and toe is now doicsuesed..but i think the dude is asking about double clutching...

l'm thinking when u shift into second...and the gear is too long...u push ur cluitch in quick to rev the enging upo and then dumping the slutch again which gives u abit of wheel spin at round 5000 rpm or more

however in sayiung this..u loose abit of time..and doesn't make a difference l duin think

[SIKCVC]

We already established on the other page what double the clutch was for :P

Back in the day before syncromesh... they had "crash" gearboxes... to be able to put it into the next gear the revs had to be matched. If you didn't match them you be grinding till kingdom come... Hence the reason why when you see movies with trucks, you hear them grinding the gears as they drive off. It was comon place because of the close ratios. Now days the only time you need to do it is if your gear box was ****ed and even still you wouldn't need to take your foot off the clutch, just match the revs.

[Jus-10]

So bottom line is, you don't need to do it becasue we have the luxury of synchros...(unless your synchros are gone of course)

[bizee_1]

Correct :!: :thumbsup:
It helps you shift smoother in the meanwhile. No amount of double-clutching can smoothen the shift on a really bad synchro though.

[carbine]

Heeltoe is for not spilling coke when downshifting

only for the maccas friday night crew.

[MKI4EVA]

Heeltoe is for not spilling coke when downshifting

only for the maccas friday night crew.

spot on!!!.........

[karbonphyber]

i always thought it was down changeing?? when ur comin up to a corner i usually just put in clutch, put it in neutral then rev it a bit then put in clutch and change down the gear, i dunnno just what my old man tought me but who who knows,lol

it's up and down =o)

from what you're doing, it's double clutching combined with heel-toe when you're down shifting.

keep on practising. =o) it's good.

[HowlonghaveIbeendrifting?]

The only time I really use double clutching is when down-shifting into first. My gearbox is a bit trempremental when it comes to getting into first gear while the car is moving, so for me it's only a necessary technique while driving in heavy traffic. Never had to use it for any other gear. However, I have heard that if you have a lightened flywheel, then you should double clutch if you are changing gears under normal driving conditions, since the revs fall quickly.

[SIKCVC]

OMG, you still wouldn't need to double the clutch, only rev match.... theres a difference.
double clutch if you are changing gears under normal driving conditions, since the revs fall quickly. if this was the case by the time you'd matched your revs and got your foot onto the clutch the revs would have droped again. The techniqure your thinking of is rev matching, which is what heel and toe is.

I will concor that doubling the clutch is rev matching however, the only reason rev matching must be done is because by the time your ready to put it into gear the revs have droped below the match point, a decent trucky wouldn't even need to touch the throttle during the process.

[HowlonghaveIbeendrifting?]

OMG, you still wouldn't need to double the clutch, only rev match.... theres a difference.
Now that I think about it, you're absoloutely right. (My bad). It's the engine speed that falls quickly due to the lightened flywheel, not the gear box speed.

[SIKCVC]

hehehe :P sorry for getting pissed. I've just heard the "yeah man doubling the clutch is much better" line way to many times, I just had another nuebie driver friend tell me he did it, and he thinks its better...

Doesn't matter. I soly blame F&F... before that movie it was only older drivers and truckies who even knew about it :P

[A'PEXi]

before that movie it was only older drivers and truckies who even knew about it :P

are you sure? do you have proof? :P

[pgclee]

ehh...i thought double clutching is for better breaking?...

why is everyone saying changing gear???
ehhh....

can people prove me that i'm wrong?????

and i thought that it's a technique to prevent your car from jamming those breaks and you can break in time to turn in the corner?

hmm...
actually, do people know wats the real reason for heel toe?...
the funny one is that...to prevent from spilling your coke!..hahaha...
hmm...i wanna know what ya guys say...hmmmm...

[SIKCVC]

Back in the day before syncromesh... they had "crash"(dogboxes) gearboxes... to be able to put it into the next gear the revs had to be matched. If you didn't match them you be grinding till kingdom come... Hence the reason why when you see movies with trucks, you hear them grinding the gears as they drive off. It was comon place because of the close ratios. Now days the only time you need to do it is if your gear box was ****ed and even still you wouldn't need to take your foot off the clutch, just match the revs.


Heal and Toe is actually to keep your revs up as your power through a corner, theres very little need for it if your breaks are good. For example you dont want to be fumbling for the next gear after you've taken your foot off the break and want to power around, It helps with times on a track. Truckies use it because it saves the breaks and helps pull up big loads, another name is "engine brakes". which is the result... truckies arn't suposed to use them around town coz its ****ing loud.

[Phat_ciVic]

i thought it was exhaust brakes they wern't supposed to use around town

[pgclee]

everybody seems to say heel toe only keeps the power up...i wonder why...hmm....

[dc2r]

This is some funny thread... a lot of people are misinformed, and some have the correct answers but then some people just want to continue to say what they think things are which just confuses everybody in the end.

Heel toe is not "engine brakes"...
Heel toe is a driving "technique"... a technique to "rev match"...
"Rev matching" is not a technique...
"Double clutching" is a technique...
"Double clutching" has nothing to do with "heel toe"...

Watch Best Motoring DVD's when they show the feet "techniques"... you will notice that they "heel toe" when coming up to a corner to "rev match"... but they don't do it for the sole purpose of engine braking but rather so the synchros do not get worn out...

[Xenon]

They do it to keep the car balanced as they set up to take the corners..

[red s2000]

umm...heel and toe is now doicsuesed..but i think the dude is asking about double clutching...

l'm thinking when u shift into second...and the gear is too long...u push ur cluitch in quick to rev the enging upo and then dumping the slutch again which gives u abit of wheel spin at round 5000 rpm or more

however in sayiung this..u loose abit of time..and doesn't make a difference l duin think

Just curious, how long since you changed your tires?

[enoch]

watch initial d.....

[gelo]

i agree with dc2r

[Muckafutha]

very late post!! sorry
but i thot double cluthing is only for trucks

[SIKCVC]

you sir, muckafutha. Have got the right idea! it was and sometimes still needs to be used in car, but now days only with POS gearboxes on their last legs.

[bumthology]

double post

[bumthology]

ok everyone, from my experience of double clutching. Doubleclutching is downshitfing matching yor revs yes, proper double clutching is not easy, every car is different. You can actually make your car sound really good if you know how to doubleclutch properly, adn the faster you do it, the more impressive it sounds(i am serious)
I've had many people in my car (that know their cars), and whenever i double clutch .. they are like "WTF.. that sounds awesome.what is it?)
hehe..



everybody seems to say heel toe only keeps the power up...i wonder why...hmm....

after u completed a turn, ur already in your desired gear, (because you've changed at the same time u were braking for that turn.)
Heel and toe combine double clutching + braking

Double clutching and heel and toe are good for the clutch if you do it right each time

[SIKCVC]

I've had enough of this... read the rest of the posts... what your talking about is not doubling the clutch.

Doubling the clutch doesn't make ANY sound except for the sound of the fluid from the clutch cylinder being pulled through and pumped to the clutch and the clutch plate opening up. Twice.

Your talking about rev matching and yes i spose it "sounds cool" but has a bigger purpose, and this whole thing is about rev matching. But Doubling the clutch is just ONE form of rev matching.

This is the steps you follow when you double the clutch... remember its for UP-shifting...

depress the clutch.
Remove gear stick from 1st (or what ever gear)
Release the clutch.
Depress the clutch again
Match the revs
Put the gear stick into the next gear
Release the clutch.

N.B. Depressing the clutch the second time and rev matching could be the other way around.

THAT is doubling the clutch... Thats the ONLY motion for doubling the clutch (with the exception of down shifting where your shifting from higher to lower)

Thats it. Theres nothing left to explain. Anything else isn't doubling the clutch. It may be a form of rev matching, but its not ACTUAL doubling the clutch technique.

[fried]

can i be the first to ask......

(yes.. im a noooob)....

whats the point of rev matching when up shifting.... wont u get more power and less time wasting if u jsut pop it into the next gear!?

never understood vin, when he said "granny shifting, not double clutching like you should be..."

[bumthology]

SIKCVC, if u can double clutch fast, ur exhaust will make a very quick rev note, match the gears and stop .. thats the sound it will make..
in a split second.
What you just said is clearly BULLSHIT
cos WHY would u need to match the revs when you upshift, all u gotta do is wait a bit
=\

thats the most pathetic thing i've ever heard.

[bumthology]

clearly, u THINK !you know what your talking about.
And i KNOW what i'm talking about. end of that.

[SIKCVC]

Yeah coz my dads NOT a truck driver is he :| (note sarcasm)

Belive what you want. Just makes it easier for people like me to drag people like you who are sitting there depressing the clutch twice.

[bumthology]

and WHO gave you the impressoin double clutching is for drag racing??
double clutching is for downshifting, not upshifting, so how does that give u an advantage during drag racing?

i can drive normally and beat u in a drag, if u tried double de super clutching or watever your method is.
=D
hehe

[bizee_1]

What you just said is clearly BULLSHIT
cos WHY would u need to match the revs when you upshift, all u gotta do is wait a bit
=\

thats the most pathetic thing i've ever heard.

IMHO, you can double clutch UP & DOWN a shift.
Double clutching is the act of :
clutch pedal in, put gear in neutral, clutch pedal out, [blip gas if downshifting,] clutch pedal in, select gear whether up a gear or down a gear, clutch pedal out.

NOW, whether you are shifting up or down, you are double clutching. From one gear to another you have clutched twice. The purpose to "double clutch" on upshift OR downshift is your choice or own discretion.

With modern day synchromesh, i find you only really need to double clutch if you have a worn synchro. You can use it for drag racing, you can use it at the track, you can use it doing a 3 point turn. Up to driver.

bumthology: my 3rd gear synchro is worn out. 2nd to 3rd shift catches or crunches when above 6000rpm. i find it quicker to double clutch into 3rd, rather than *wait a little bit* when shifting normally. This way, i force the synchronising, rather than wait for the synchronising.

"rev matching" is normally done on a downshift. you can rev match when double-clutching down a gear, or when normally down shifiting a gear.

"heel-toeing" is braking & rev-matching on a downshift. you can heel-toe when double-clutching down a gear, or when down shifting normally.

BUt....i could be terribly wrong :?

[fried]

*ding*

thank you.

now we can stop flaming, lol.

[Muckafutha]

whao this is getting hot.
but i stand by sikcvc.
like i said trucks use it cos they have lousy or worn synchros, tink another forumer mentioned that
i know cos the trucks in my country suck and in order to get a truck license i had to learn to double declutch as it is a requirement for the driving test. i dun really tink the tester wants to see how fast i can throw the truck into the corner and rev matching and stuff

[Yapster]

this is interesting n i will share my 2cents.

Double clutching:
main thing is for cars with worn synchros, or race cars with no synchros. so unless you are planning to drive a race car, theres really no need to practise this.

Heel (not heal) n toe:
when u are approaching a corner u have to slow down right? but if u use the brakes only theres no engine braking so the car is very unstable. n when u exit the corner, your revs wld have fallen as during the corner u were on the brake or on very little gas.
so u heel n toe, that is as u approach the corner, u brake, clutch in n downshift (foot still on brake) then with the HEEL of your right foot (TOE still on brake) depress the accelerator to match the rev to the lower gear ( cos at same speed when in 4th ur rev might be 3000rpm but in 3rd its like 5000 for eg) let go of the brake while still feathering the throttle n release the clutch.
this keeps ur engine on the boil while going thru the corner. it also prevent the car jerking if u just drop gear without matching the rev as that can seriously upset your car, esp in a [acronym:b699ccc94b="Front Wheel Drive"]FWD[/acronym:b699ccc94b] thru a corner.

just my 2cents

[Muckafutha]

i thot there is engine brake whenever u release the accelerator??

[Yapster]

there is, but there is significantly less engine braking when you're in 4th gear compared to 3rd right? the key is to not float thru the corner depending only on your brakes, but let the engine share in the braking role.

[Javed]

I double clutch all the time. Pointless for upshifting IMO. I do it on downshifts cos my synchros are a bit worn, and it also is better for your box and synchs in the long run. Double lcutching is also good prep for heel toeing which I have nearly fully mastered now. Too many people here think all this shit is important and "I am better than you cos I can do this that rev match blah blah blah". Truth is, until you put it into practice on the track or whatever in a race against another individual, what you say on the internet means shit. So most of you guys just need to chill.

[SIKCVC]

lol with javed(was gonna say at but not laughing at you :P) so true... I've been a bit of a keyboard worrier on this topic but I'm more than happy for someone to come for a spin and fault my shifting technique. Matching the revs is the most important thing to remember with any shifting reguardless what your doing, up down round and round. If you dont rev match properly it'll be rough uneven and wont do any good for your box.

/last rant ever on this topic... if anyone wants to judge my driving PM me and I'll take you up the twisties.

[Javed]

lol, wasnt targeted at you mate, I know im not a perfect driver (very very far from it), yet I can double clutch. However as I assume you know, it is not something worth bragging about? Everyone can appreciate a driving technique, but claiming it isnt really the way to go. And to reply to that fast and the furious quote that somebody already notably ridiculed. Who double clutches in a drag race anyways? If you are gonna use the clutch at all, you definitely wouldnt be double cluthcing on a race that contains 100 percent of shifting up. I pissed myself at that line, everybody looked at me funny. :D

[h22a accord]

ever noticed that the really good drivers in the world are very modest about it. Does that mean that the people out there that say they are good/better than you etc are actually lousy drivers.

big deal, we can all use an accelerator and brake to drive fast but what worries me is when something goes wrong.

when i was 18 i used to think i was the worlds greatest driver, i look back on it and realise that being a good driver is not about how fast you can go through a roundabout or take a corner. being a good driver is knowing your cars limits, road conditions, your own ability and driving in such a way so you wont end up crashing.

Im older now and realise when i was 18 i could have easily been another statistic cos in reality i was an unexperienced testosterone driven young driver that was a danger danger to my self and other road users.

I still would like to do some driver training one day in controlled conditions.


/rant

[SIKCVC]

If you want to have a winge because people dont mind being arrogant post it in another thread. Just because a driver states that they have aquired certain skills in a certain length of time, which may be more advanced or quicker than you could have, doesn't mean they they're poor driver/havn't honed other driving skills. But if you havn't noticed the subject is actually about "track" skills NOT road driving ability.

[h22a accord]

If you want to have a winge because people dont mind being arrogant post it in another thread. Just because a driver states that they have aquired certain skills in a certain length of time, which may be more advanced or quicker than you could have, doesn't mean they they're poor driver/havn't honed other driving skills. But if you havn't noticed the subject is actually about "track" skills NOT road driving ability.


mate i never said that any one is a poor driver, i was reflecting on my own driving abilities. i post what i like here cos im not the one whinging :lol:

[gelo]

hey guys
in my opinion, there are 2 ways of heel and toe
i was just wondering which one do most ppl dp
1) brake, clutch in and down shift while heel and toe-ing, clutch out
2) brake, clutch in, shift to N, clutch out, heel and toe, clutch in shift down, clutch out

[SIKCVC]

no need for the second one unless your g/box is on its way out.

The first one is almost right, but after a few months of it and then you'll have to use the second one coz you'll mash your g/box.

You need to match your revs(heel/toe) before you put it into the next gear otherwise it can still grind and mash around a bit. BUT your foot only depresses the clutch once as you have noted.

Like I said unless your g/box is mashed there no need for the second one, not to mention it is extremly slow and at 120-140km entering corners you really dont want to get caught up with your downshifts. In all honesty if your gonna waste your time clutching in twice during heel and toe you might as well brake, rev match without heel/toe and brake again.

Just some notes :P but in short the first one.

[gelo]

so your saying

brake

clutch in

downshift but heel toe b4 u go down to the lower gear

then clutch out


to be honest
ive been using the 2nd method ever since i got my car (2 months?)
and im pretty used to the 2nd method

when i watch BMI and stuff i always notice how they only clutch once per heel toe

my friend (who taught me heel toe) said clutching twice wear out the syncrhos less

im finding it hard to change my habits and go to the 1st method

[SIKCVC]

the 2nd one is just unessisary and slow, but if your 100% smooth with it, its the best for your g/box, but in comparison to single clutching your talking;
98% for single clutch
100% for doublt clutch...

If that.

[SIKCVC]

If anyone has an FTP site and are willing to upload some vids, I was bored and filmed Doubling the clutch and Heel toe technique... man, first time I've bothered trying doubling the clutch... Biggest waste of time ever.

[viperx]

this post is so f*ckin long i have lost track

But sikcvc... i think you have missed the point... there is no point 'rev matching' if you don't double clutch... because you are only matching your flywheel speed to the diff shaft... you realise without shifting back into neutral, releasing the clutch, then blipping the accelerator, the layshaft isn't involved and it just keeps slowing down. and so yes, if the layshaft isnt involved, your gears aren't matched to your wheel speed when you shift in.

If you do what you're doing then you might as well just apply more accelerator as you release the clutch, it's the same.

and if you think you can just rely on your synchros, think again... why do some cars have triple synchro cones? because the single synchro cones in our cars aren't designed for the beating they can get at race speeds. thats why you want to match revs using heel toe + double clutch. And it's not too hard. Like anything, it needs work but its doable.

[viperx]

And if you guys don't know what i'm talking about, plz do your reading before you reply

http://auto.howstuffworks.com/transmission3.htm

[bennjamin]

...blah.

To add finally...ive spent most my legal driving life driving small trucks and vans etc for my old mans company - and due to experience - double clutching becomes second nature.....basically...because to slow down a 15 ton vehicle you must use the gears and not the brakes :)

oh....having size 13 shoes , and very long toes really does help too :)

[viperx]

Like I said unless your g/box is mashed there no need for the second one, not to mention it is extremly slow and at 120-140km entering corners you really dont want to get caught up with your downshifts. In all honesty if your gonna waste your time clutching in twice during heel and toe you might as well brake, rev match without heel/toe and brake again.

Just some notes :P but in short the first one.

Have you ever tried this?? do you want to lose control of your car? How can you brake, then let go of the brake, and then brake again while cornering? you will fly off the road!!

[viperx]

if you do this, you will firstly shift your centre of gravity towards the outer front wheel. then when you release the traction from this wheel will decrease and the car's centre of gravity will be moving backwards towards the inner rear wheel. if you brake again during this time while still cornering your car will lack centripetal force, and you will shoot out on a tangent.

the key to grip is to never set up a pendulum effect in your car's centre of gravity!

[viperx]

so your saying

brake

clutch in

downshift but heel toe b4 u go down to the lower gear

then clutch out


to be honest
ive been using the 2nd method ever since i got my car (2 months?)
and im pretty used to the 2nd method

when i watch BMI and stuff i always notice how they only clutch once per heel toe

my friend (who taught me heel toe) said clutching twice wear out the syncrhos less

im finding it hard to change my habits and go to the 1st method

They clutch twice

There's no point clutching once, you don't do anything by dry revving your flywheel! you don't match the next gear to the shaft as the gearbox is TOTALLY disconnected from the engine!! the clutch is before the gearbox!!

[gelo]

well
perosnalyl i used clutch twice in my heel and toe's

ive been watching the BMI abd option videos lookign just at the foot camera
and it seems as tho they only clutch one per heel-n-toe downshift

now me and my friend reckons they make depress the clutch fully and ease off it past friction point then rev match and depress the clutch fully again

i swear it looks as if they only clutch once

[SIKCVC]

Have you ever tried this?? do you want to lose control of your car? How can you brake, then let go of the brake, and then brake again while cornering? you will fly off the road!!

My point was that its slow either way... of cource I'm not fcuking stupid enough to do anything as retarded as that!!! I didn't say brake while cornering!!! read it again.


well
perosnalyl i used clutch twice in my heel and toe's

ive been watching the BMI abd option videos lookign just at the foot camera
and it seems as tho they only clutch one per heel-n-toe downshift

now me and my friend reckons they make depress the clutch fully and ease off it past friction point then rev match and depress the clutch fully again

i swear it looks as if they only clutch once


They would only clutch in once... Unlike us they're not stressed about gear box longevity, they're only worried about times.

[viperx]

My point was that its slow either way... of cource I'm not fcuking stupid enough to do anything as retarded as that!!! I didn't say brake while cornering!!! read it again.



They would only clutch in once... Unlike us they're not stressed about gear box longevity, they're only worried about times.

For one thing, its not slow to heel-toe and double clutch provided you have had enough preparation going into the corner. If your foot is on the brake when approaching the next bend then why is it slower if you can fit the double clutch in at that time? And yes it is not too hard to fit double clutching in. Nobody told you to blunder into corners unprepared. Its a skill that needs to be practiced. And my point isn't even braking while cornering. Its the fact that you can't take your foot off the brake, go and do something and then brake again while applying a lateral force. You will upset the car's balance and in high speed situations, lose traction (ie. lost time), potentially even roll the car.

And secondly, they are worried about gear box longevity. You realise that in BMI a lot of the time they are not driving dog boxes. They are road cars being subjected to race conditions. If they weren't worried about longevity, don't you think they would be flat changing on the upshift all the time? Why clutch at all?

Thirdly, if they really are clutching in once, then they do not need to blip the throttle WHICH THEY DO. I thought I had established that blipping the throttle without releasing the clutch DOES NOTHING except waste a bit of gas. It DOES NOT match your gear speeds because the layshaft is not connected when you blip the throttle. Please do your theory...

Driving with mechanical sympathy is a skill. Driving fast is also a skill. That is why driving fast AND being mechanically sympathetic is hard.

[fueltank]

Thirdly, if they really are clutching in once, then they do not need to blip the throttle WHICH THEY DO. I thought I had established that blipping the throttle without releasing the clutch DOES NOTHING except waste a bit of gas. It DOES NOT match your gear speeds because the layshaft is not connected when you blip the throttle. Please do your theory...


haven't read the whole thread...but wouldn't blipping the throttle keep the revs up besides wasting gas? :rolleyes:

[viperx]

It only keeps the revs up in everything up to the flywheel. So it's pretty much useless.... if you don't release the clutch, then blip, then clutch again, then your gearbox slows down.

[saboteur]

Do you guys that heal-n-toe have aftermarket pedals? I find it pretty hard to do in my car (throttle in particular), but in my mate's BMW the pedals seem to be in a much nicer position. It would be a great technique to learn for those track days.

Cheers,
Tim

[fueltank]

heel-toe is used to avoid abrubt weight transfer. If smoother shifts are what you're after, then double-clutching is the answer: put it in neutral then let the clutch pedal out (flywheel is now connected to the layshaft but not to the differential because it's in neutral) then give it gas until the layshaft is spinning at the correct speed for the lower gear, then QUICKLY push in the clutch, shift to the lower gear and release the clutch, all before the revs decrease. In most racing today, double-clutching is not used because syncros make it unneccessary and it would only increase shift times, but some people still like to practice it--mostly so they can add another driving skill to their repertoire.

[SIKCVC]

Thirdly, if they really are clutching in once, then they do not need to blip the throttle WHICH THEY DO. I thought I had established that blipping the throttle without releasing the clutch DOES NOTHING except waste a bit of gas. It DOES NOT match your gear speeds because the layshaft is not connected when you blip the throttle. Please do your theory...



You've obviously never heard of compression lock, which is a far bigger issue to a race company with $$$ to spare but not seconds. Without increasing engine revs to match road revs you will get compression lock at high RPM...

Theres more than mechanics involved...

You've established nothing except for the fact that syncros will slowly die if you dont double the clutch. and Flat shifting is far more damaging to engine parts especially considering the engines are under considerable load on accell compared with decel.


Its the fact that you can't take your foot off the brake, go and do something and then brake again while applying a lateral force. You will upset the car's balance and in high speed situations, lose traction (ie. lost time), potentially even roll the car.
Tractions not the issue here, if you attempt this at the same distance you would heel and toe your gonna end up off the track because you'll enter the corner too hot. Thats the biggest issue.

Heres a quick experiment... try and make your mouse tip onto its side by only applying sidewards force... its not gonna happen... center of gravity is too low. The arab drifters are the best way of seeing this in action (130-140km then full lock steering wheel in stock camry's, they spin about 4-5 times) The only thing that will change this is if you apply a strong enough force apposing the CofG at a lower point, ie hit a gutter.


If they weren't worried about longevity, don't you think they would be flat changing on the upshift all the time? Why clutch at all?

I've mentioned flat shifting... and in a lot of cases race drivers WONT clutch in on upshifts. They're skilled enough not to. I recomend anyone who has the balls/knowledge of their car to try it... its a peice of piss. Granted I'd never try it at high revs but it can be done.


And my point isn't even braking while cornering.

Just as a side note its only really FWD that you cant left foot brake in... its a commonly used technique in RWD's. That is where you balance a car around a corner with both throttle and brake.

sorry for the essay... a lot to reply to.

Edit: What Fuel tank Quoted is spot on.

[SiR JDM]

I read nearly eveything in this thread but I couldn't find anything about clutch ware....

The way i was informed (which could definatly be wrong so bear with me :P)
Rev Matching is the best way to preserve ur clutch, letting the flywheel and clutch spin at the same time causing the least amount of friction?

Similarly with Heal Toeing, I have a friend that heal toes every gear down ... Its a smoother ride.. i can vouch for that, but he also claims the clutch life story...

Is this true?

[SIKCVC]

its more for racing to prevent compression lock and to set the car up in a balanced power possition around a corner... as viperx has pointed out, its not great for your syncros so not something you should be doing all the time. unless your super fast and smooth at doubling the clutch during heal and toe.

Its an old line but it hasn't been mentioned.

Gears are for going, brakes are for stopping.

[fueltank]

Just as a side note its only really FWD that you cant left foot brake in... its a commonly used technique in RWD's. That is where you balance a car around a corner with both throttle and brake.


I think this is wrong.

[SiR JDM]

So do I... im pretty sure the eg6 does that in initial D...
proof right there :P

[SIKCVC]

I didn't want to try it since I have front bias brakes and apply brakes and throttle would meirly counteract eachother.

[viperx]

No, tell us what compression lock is. I've not heard of it before. as my understanding goes, most of the inertial load is after the flywheel, so pressing the accelerator to speed up everything before the flywheel doesn't do much anyway as when the clutch disengages the flywheel will be slowed down enough so that your initial blip doesn't do anything.

What is wrong with using the engine and drivetrain as an inertial load to stop your car again??

It's not clutch life Sir JDM, it's synchro life (and hence gearbox)

[viperx]

Tractions not the issue here, if you attempt this at the same distance you would heel and toe your gonna end up off the track because you'll enter the corner too hot. Thats the biggest issue.


I thought I'd established that it takes planning to drive at a reasonable pace on the track and use track techniques. If you'd planned on enough time to use such techniques why will you enter 'too hot'? entering a turn 'too hot' indicates poor planning as it means you've entered a turn at too high a speed to perform necessary manuevers!

How can traction not be an issue? Traction is an issue even in drifting...


You've established nothing except for the fact that syncros will slowly die if you dont double the clutch. and Flat shifting is far more damaging to engine parts especially considering the engines are under considerable load on accell compared with decel.

I'm really not so sure about this. They are both accelerative forces (i mean in a physics sense- changes in velocity). Why will acceleration put an engine under more load than deceleration if the change is at the same rate? Please explain this...

[SIKCVC]

Why will acceleration put an engine under more load than deceleration if the change is at the same rate? Please explain this...

Its not at the same rate.

[viperx]

How can you compare the two without making them the same then?

[SIKCVC]

I'm not comparing them? that was what my point was. I said that accell had more load on the engine etc then decel,

[viperx]

This is starting to feel like nitpicking. :D

[jko2]

omigosh, i don't visit ozhonda very often (only when ns.com is down), but couldn't help reading this thread! it seems like everyone here has no clue on these two techniques!! and you guys are suppose to be track warriors!

the only guy that has it right is VIPERX!!!! take time to read his post and think about it and it will make sense!! id type out the explanation in simple dot points but viperx has it right - just need to read it and think!!

and to those who think double clutching is used for up shifting... you've been watching too much f&f!!

[SIKCVC]

Well no if you read the link viperx posted doubling the clutch used to be used on crash gear boxes up and down.

I see where viperx is coming from, needing the gear box revs matched in order to preserve the syncros... and I know I'm trying to learn the technique but if i need to down shift fast, I dont give a rats about doubling the clutch(ie my syncros) I just dont want compression lock due to low engine revs and hi road revs... which is my point for blipping the throttle.

and Viperx it only became nit picking when you made stupid nit picking rebutals. My main goal when down shifting into a corner, is to set myself up for the corner and the exit, I dont want to get caught out stumbling over peddles/taking to long to down shift... and i especially dont want to get compression lock. if that means matching engine to road revs without matching engine to gear box revs, so be it. Lets face it honda gear boxes can take a fair bit of punishment.

[Cyrus]

Why argue,...,a technique is good if it makes you go faster.......whatever works for the person,..., no one's right or wrong,..., race car drivers do what they do because it's proven, I believe there are some aftermarket ECU's that will incorporate a flat changing function. Otherwise, I wouldn't try it unless you love to buy new synchros

[SIKCVC]

good call cyrus.

[viperx]

That's cool with me cyrus- i didnt accuse anyone of nitpicking. I only said that because I didnt feel like arguing anymore. And sikcvc, I have nothing against you, perhaps you worded your answers wrongly, but it just seems a little defensive for you to call my comments stupid. There is nothing technically wrong with what i described. I know what the limits to my knowledge and skill is and i don't feel the need to prove them to anyone, and I happily admitted I don't know what compression lock is, and I would like you to tell me if you're willing.


And thats the ONLY time you would need to use it in a veihcle where the syncros are ****ed(this includes missing a gear and having to reset it) or not even syncro gear box... if you use it any other time your an idiot and deserve to be shot!!!


But why are you trying to learn double clutching now?

[dundas]

c'mon children. double clutching is doule cluthing-- if you can master it.. good on ya...your synchros will love you for it...^_^,
all i know i love the feel of double clutchin when down gearing into a corner...it reduces the bounce of the car and allows you to take the corner at the right speed and revs ^_^=== great for hills ahahahaha

[SIKCVC]

Well to be honest ViperX I learnt a lot of stuff I know from my dad who was a susy and exhaust expert. He has done a lot of work on cars over the years including gettings my mums mini to wheel spin in every gear. Not to mention being friends with that crazzy roller mechanic in europe with the car that has a spitfire engine in it.

He had told me the usage of Doubling the clutch, which was on crash boxes (or what ever he called them) where revs HAD to be match in order to get it into gear. Without matching revs of the layshaft, engine and road it just wouldn't mesh.

After reading that article/info peice I can understand why its usefull when time permits I will do what I can to preserve my gears... esspecially at downshifts around 5000-6000rpm but in the lower gears (tight quick corners)... sorry syncros speed is of the essence.

Compression lock up... http://forums.melbccr.com/showthread.php?t=65493&page=1

[viperx]

Thats cool, i respect your experience... :)

Now i know what you're talking about... you're matching the engine output to the load (regardless of whether it comes from compression or friction) it has to work against (including engine and drivetrain) before engaging the clutch so that the power to speed up the engine revs to the neccessary rpm doesn't come from the rotation of the wheels...

But that's achievable just by increasing the throttle opening as you release the clutch right... it doesn't involve blipping the throttle (ie pressing the accelerator down and letting go, then pressing it down again)....

[SIKCVC]

Its a lot smoother and faster to blip the revs. When I was learning downshift I tried it the way you mentioned but the revs tend to far out and it takes to long to match them up... all of which defeats the purpose of downshifting.

[viperx]

Fair enuff i guess... :)

[linkorr]

urm this is interesting. Thanks for pointing out the compression lock issue. Can anyone tell me what happens if compression lock occurs? Besides the usual 'f-ing up of synchros'. I don't think I've experienced it before and would like to know the after effects on the engine. Would it (engine) seize/lock up? or would the engine speed matched the wheel speed (very abruptly) or vice versa? ie. more inertia, engine will match. Powerful engine, car speed/velocity matches the engine.

[SIKCVC]

Its exactly as the name suggests... the wheels lock up. Wont do any more harm to your syncros than any other downshift without matching the layshaft speed.

[SINISTR]

Hi All,

new here - only the second post... and unfortunatelly I don't have the time being at work to sit and read all 8pgs of posts, so I apologise if I miss something or repeat something...

I think double clutching is only used in OLD cars, Trucks and Synchro busted newer cars. When driving and shifting upwards, technically only old boxes and trucks need to upshift, HOWEVER with todays oils, and mechanical advances it rarely happens even in those circumstances - people fix things.

I think alot of people seem to look at the movie Fast&Furious and hear VanDiesel say 'not double clutching like you should...' straight after the first Drag race... double clutching in any of those cars in that movie in an upshift would do nothing more than loose them time!

In my opinion - forget double clutching - and if you need to do it, get your gearbox fixed so u don't have to do it.

Heel n toe - its a common technique for race car drivers, rally drivers and its trickled down to US - road users. I use it just about every time im slowing down to a corner or even a set of lights. as explained before by some people, it involves toes on the brake and your heel or side of your foot on the accelerator blipping the pedal to raise the revs and eliminate whats called 'compression lock - engine speed slower than road speed'. It allows you to step on the gas and accelerate almost instantly, to pull the car out of a corner even with still having your foot on the brake. You can sometimes notice footwork by some japanese racers, in some race movies that come out. Observe that - and learn from that.

I hope i didn't step on any toes here... that was not the intention...
cheers
Mike

[viperx]

why would you want to blip the throttle on upshifting? you need the layshaft to decrease speed anyway.

[SINISTR]

ive seen BIG trucks double clutch when shifting up - its the way their gearboxes are designed I guess - this isn't in ALL trucks, only in the OLD Skool ones - i know definatelly in europe some trucks do that hence why I said some old cars and trucks need to double clutch when upshifting even...

mike

[viperx]

unless truck box design is totally different i don't see how it physically works shifting UP... down is good...

[vtml]

I double clutch changing from 1st to 2nd on cold starts as 2nd crunches. That's as far as double clutching goes for me.

[Type R Positive]

ive seen BIG trucks double clutch when shifting up - its the way their gearboxes are designed I guess - this isn't in ALL trucks, only in the OLD Skool ones - i know definatelly in europe some trucks do that hence why I said some old cars and trucks need to double clutch when upshifting even...

mike
yeah, that is when they are using the little gears between gears, some have low, mid, and high in each gear. on a 9 speed box, that's 27 gears! It's for pulling massive loads. It's friggin hard to do it, I've tried.

[BF]

Its unnecessary anyways!

[viperx]

yeah, that is when they are using the little gears between gears, some have low, mid, and high in each gear. on a 9 speed box, that's 27 gears! It's for pulling massive loads. It's friggin hard to do it, I've tried.

It's not for pulling massive loads. its because many truck boxes dont have synchros.

And bizzy, before you comment read the rest of the thread. we have spent quite a while wringing the topic out with a reasonable amount of technical information and for you to come in and comment without any back up is just a reflection of your inability to have patience to read, to understand, or to be mature enough to put in the effort to practice.

And vtml, that probably means your synchro is fully stuffed.

[BF]

A thousand apologies

[Type R Positive]

It's not for pulling massive loads. its because many truck boxes dont have synchros.

And bizzy, before you comment read the rest of the thread. we have spent quite a while wringing the topic out with a reasonable amount of technical information and for you to come in and comment without any back up is just a reflection of your inability to have patience to read, to understand, or to be mature enough to put in the effort to practice.

And vtml, that probably means your synchro is fully stuffed.
I drive these trucks toss.

[viperx]

I drive these trucks toss.

Ok, my bad... It's not JUST for pulling massive loads in trucks. That was wat I meant. The technique does have it's uses in vehicles weighing less than 2 tonnes.

[Type R Positive]

yep sorry mate, I was explaining about the trucks.......

[toE]

So tell me exactly how you "double clutch" and what are the benefits? is it worth double clutching when you drag someone off the lights? :?

All 3 questions have been answered! :cool: