Lets not forget the precision involved in the technique. Note how while blipping the throttle three times the pressure on the brake pedal is perfectly constant. This contributes to the smoothness of the down changes and progressive deceleration. Great stuff.
That's right. Double-clutch downshifting is BENEFICIAL for ALL manual transmissions, but only NECESSARY in non-synchro transmissions. Clutchless shifting works for non-sychnro transmissions as well.
To the people that say double-clutching takes longer and is slower, you are wrong. With double-clutching there is no time spent waiting for the synchros to match speeds, so the shift lever moves to the next lower gear with no resistance. Also, there is no need for faster downshifts as there is so much time in the braking zones, downshifts can be made almost leisurely.
The driver lets in the clutch (releases) every time he blips the throttle. This is very important as not only do road speed and engine speed need synchrnonising but also the synchros in the gearbox. This prolongs the life of the synchros.Another subtle refinement to the technique is that the blip's duration be commensurate with the gaps in each gears ratio. Ie. close ratios--short blip,wide ratio--long blip. A pleasure when done right. A pleasure to watch. A pleasure to hear! Well done indeed.
i never realized i drove that good till seeing this...this is how i drive my daily driver 5speed soch neon with full bult on...i shift/drive just like him.
OK, I'll ask myself. "Do you double-clutch, Gary?" "Why, yes I do, Gary, thanks for asking." "Why do you do that". "Well, because it completely eliminates synchro wear and doesn't take any additional time to do it." "Well then why doesn't everyone do it?" "Because some people learned one way and others learned another. It's personal preference, really. You don't HAVE to do it, but saving parts of the car at no expense in speed seems pretty smart to me!" Now go ride your Bigwheel.
fre2fly...the smooth changes that double clutching provides help improve lap times in racing. It also saves on the gearbox. Double clutching is not normally absolutely necessary on a street car, but it does save wear on the synchros in certain downshifting situations.
Hey, love seeing somebody else double clutch when downshifting. Makes the gear change so much easier. I'm a truck driver and of course use the technique when driving truck (if I even use the clutch lol) but now do it in my car too on the downshifts.
What you described is Heel-toe Downshifting... Double-clutching is very useful. It allows you to engage your gears faster without putting extra stress on your synchros, once you have it down it is actually faster than not doing it.
The concept is called rev matching in some magazine I read years back. Maybe Import Tuner or something. Rev matching is simply giving your engine some gas before you let the clutch out into gear so the engine speed is about the same as it would be in gear. The result is a smooth engagement and transition from gear to gear or neutral into gear. If you don't rev match you get that jerking feeling of near whiplash when your engine surges from 750rpms to 5,300 rpms.
i'm a truck driver and use the clutch sometimes. it depends on road conditions and the load you're pulling. when starting from a stop going uphill pulling 80,000 pounds, it makes sense to clutch it to be on the safe side. i also clutch on downshifts sometimes.
The whole concept of Double-Clutching came about from racers during the early days of open-wheel racing. Back in the 20's when actual transmissions (or "gearboxes") were being used, most were three speed and had NO synchros. Therefore, the only way to get into the next gear (up or down) without losing much speed and w/o killing the gearbox, one would have to rev-match to allow a smooth and safe transition from one gear to the next.
When you select any gear (except reverse) a soft brass synchro cup, which is splined to the output shaft, slides up against a cone on the side of the desired gear. The friction between the synchro brake and the gear cone matches the speed of the two until the synchro gear teeth can lock the desired gear to the output shaft.
It allows the engine to slow down so the transition into the next gear is much smoother. Basically instead of shifting into the next gear, you first shift to neutral. Rev match, and then clutch + shift into gear. Most cars have synchros now, eliminating the need to match in everyday driving. But race cars (afaik) can get more power if they don't use a synchronizer.
On downshifts, clutch in, as the shift lever goes through neutral, the freely spinning gears will rapidly slow down and eventually even stop. As you try to slide the lever into a lower gear, that one gear's synchro brake works hard to spin the entire gear train up to the correct matching speed before the gear can be engaged and locked to the output shaft.
This technique is primarily used to smooth the transition of gear changes, primarily in rear wheel drive cars. It's not used to make the car slow down faster but this can be done with some car configurations (typically AWD platforms) but I wouldn't try that in to your Sunday driver. In drag racing you should be power shifting, and yes it's only needed for down shifts. This will make you quicker on a road course, yes, but only if done properly.
well said 70tKAWAn, perfectly explained the mechanics of d/c. yeah it took me 6 days to get a hang of it and like 2 weeks to do it naturally. the hardest thing was to overcome in you mind, that you're BRAKING and at the same time you actually press on gas pedal WHILE your clutch is UP. i found it was so weird at first and kept thinking my car will jerk that my left leg just refused to obey my order..
the old cars or entry level formula cars don't have synchrons in the gearbox so that by revving the engine with the clutch down it doesn't really spin the flyweel and you can't match the revs. Therefore, you have to clutch to realease the gear, let the clutch up, rev the engine then clutch down to enter the lower gear. You can also push the gear out while braking without clutching, then rev the engine and hit the clutch only once to enter the gear but the trani might not last as long.
it is called "blipping" the throttle. his right foot is applying the brakes to slow the car down, he is gassing the engine with his right heel to raise the RPMs then releasing the clutch when the RPMs match the road speed to the engine RPMs for the selected gear.
Double clutching is a very good technique to know on high mileage vehicles, or transmissions that were not blessed with great synchro's to begin with. It will not hurt a synchromesh transmission, but it can lead to premature clutch failure. Shifting without the clutch is another story when it comes to the synchro trans.
Great example of braking whilst heel-toe double declutching. The 80's group B rally guys were the kings at it, check out some old skool rally vids if you wanna see quick heel-toe in action!
@mashimartin He's doing both. Heel-toe is used to apply throttle while breaking (obviously) He's using it to double clutch his downshifts while breaking so he has the least amount of breaking time to increase lap times and maintain control. Heel-toe can also be used to apply throttle while in gear, while breaking and counter steering to control a car in a slide (drifting.)
The output shaft always turns with the driven wheels as they are always joined by the driveshaft. The input shaft, the heavy countershaft, and all the other loose gears on the output shaft are all driven by the engine whenever the clutch pedal is released, or are all connected to and driven by the driveshaft whenever any gear is engaged with the gearshift lever. All that mass has a significant rotational inertia.
i too double-declutch heel&toe all the time. once you get used to it it's very useful. purpose of doing this is: a)protect the syncromesh which after heavy use it starts to work less effectively therefore you do the syncro yourself - spin up the input shaft while you're in neutral and when the rev matches quickly clutch in and slot the gear in.
double clutching is useful for production car because normally a common everyday car has a gear guard. A gear guard prevents u downshift to a lower gear at high speed, as this is likely to damage the engine and gearbox. Many of you may have experienced that, u want to downshift(IE.3rd->2nd@45mph), though the car is pretty capable to run 50mph@2nd gear, u find it's stuck and u can't downshift to 2nd untill u slow the car to 25mph. Double clutch solves such problem.
Yep, that's Heal & Toe Downshifting. Search for it on here, there's plenty of videos. The blip the throttle with their heal whilst braking with their toe to balance the vehicle, match the engine revs and it helps with quicker acceleration out of corners.
errpatrullero, at 18 seconds, count how many times my left knee goes up and down (six) and count how many gearchanges you hear (three). Two clutch throws for each gear = double-clutch. Watch the video again and you will also notice heel-toe downshifts. This is a video showing heel-toe double-clutch downshifts.
it eases the gear shift and helps match the RPMs better. there is not real point if you have synchros, they say it still works though. but Double declutching is mainly for cars without synchros, commercial trucks and motor cycles (cause its such a small ratio and pedal engaged throw, forcing a shift doesn't really matter)
un-synchronized gear boxes are used in race cars because they are lighter and they don't wear as bad as synchronized ones and also you can shift faster with this type of transmission. and double clutching is for keeping the revs up to the engine's max power range when downshifting
it reduces wear on your transmission by matching the engine speed with that of the gear you are shifting down to. Plus it makes for a smoother gear change because engine and transmission are more 'in sync'.
Rev matching works best when in neutral, so you are actually spinning up the transmission. Getting the engine speed up is just part of the overall idea. When you are in neutral, the transmission is slowing down.
Also, over exagerated heel-toe blips do the same thing. The input shafts pilot bearing does create some drag on the shaft. By over blipping, you do the same thing as double-clutching.
I agree, but it is great for downshifting - smooth, fast, and much easier on the parts. I would say it is the only way to downshift unless the new lower gear would correspond to less than 1000 rpms
@joshGNR2 To explain double clutching, you need to know about heel-toeing. This is a teqnique used while downshifting to: 1) prevent the locking of tires on a downshift, and 2) prevent over/under revving. When you go to brake, when you downshift, rather than just letting the clutch out, you give it some gas with your heel as you clutch out, to bring the revs up faster. This prevents the lock. Then you have an idea where your RPMs are at, and you will know if you need to go down another gear.
@cadillacdude1975 ...this way while you use your engine to reduce speed, you will prevent losing traction due to shift-lock when downshifting. It also will keep the car in balance while braking so you can brake almost until the apex without missing the line. Correct me if i'm wrong please.
@LT1HILLINGHOE You're right, there's no need to double clutch a synchronized transmission. The point of double clutching here isn't to keep the gears from grinding, but to prevent the lurch you get on a downshift by matching the engine RPMs, and retaining as even weight distribution as possible. This is how race drivers don't spin or lose time in corners. Drifters also use heel-toe control and double clutching to maintain control during a drift, another topic and application entirely, though.
rev-matching is not just average, if you ask me. But the difference is, if you rev-match with the clutch down you only speed up the parts up to the flywheel. If you shift in neutral and let the clutch out and then blip the gas, you speed up all the transmission parts involved. Less wear
yes double clutching has little effect, but the heel-to-toe make your car drive a lot smoother and allows you to accelerate out of corners at a much faster rate, with more control because of the weight distribution is not all towards the front because of a harsher shift.
I would never double-clutch an upshift in a racecar as it would be a huge time waster. You will notice that I don't double-clutch the upshifts in the video. Double-clutching downshifts has nothing to do with keeping RPMs up or with keeping the boost up. It's about matching transmission input shaft speed to engine speed.
@surlograsp If you use your second example, the clutch spins way faster than the engine, and only single clutching wouldn't allow your clutch to slow down. Double clutching lets your clutch slow down, and rev matching (Throttle) makes your engine speed up. These combined will get your engine rpm and clutch rpm close, minimizing slippage when shifting, saving your clutch and syncros.
I know this is RUclips and a lot of users here like to throw around insults while hiding behind made up usernames, but I still don't appreciate being called an idiot. This WRX racecar has an OEM transmission, clutch disc, pressure plate and flywheel. I double-clutch because it eliminates synchro wear. As one of the people responsible for rebuilding the transmission when it shits the bed, I like to reduce the number of times a season me and my crewmen need to crack it open.
double clutching was used in manycar racing series before synchros. Nowdays you really don't need to double clutch due to having synchros, just a propper downshift is all you need, all you trying to do is to match the revs of your motor and trans.
The primary purpose of this technique, as I understand it, is to help manage the BALANCE of the car when it is at the limits. Managing the weight balance of the car is paramount in high performance driving.
@Overdrive872 Actually he is double clutching as well if you look at his left foot on the downshifts. And it wasn't used only for trucks in the past. It's still used for all kinds of racecars without syncros and not solely trucks.
Heel-toe is actually more advanced than double clutching; it is double clutching, while braking. This is tough to do under light braking because tapping the throttle will usually cause you to tap the brake further as well. Heel-toe is really only useful for hard braking, and thus race driving since you won't likely be downshifting while hard-braking in traffic to avoid a wreck.
On a non-synchronized gearbox you need to let the clutch out in order to get the input rev speed to match the gear's movement when it meshes. If you're rev-matched without double-clutching then you are rev-matching a synchronized transmission.
The way he does it in the video is a little better than the way you described it in the last sentence. He's shifting into each gear on the way down which allows the transmission to be sped up by the syncros (which is bad as you said above but not as bad as going from say 5th gear to 2nd) but it's faster and safer since you're never in neutral.
@joshGNR2 When you heel toe, the process is: Let off gas, brake, clutch in, downshift, shift heel and gas, clutch out enough to bring the engine's revs to the transmissions gearing, and repeat all but the first two steps. Once you're at the desired speed/RPM, you let off the brakes, and clutch out fully, and begin acceleration. This is the basic rundown of heel-toeing. What double clutching does is shorten the amount of time that the clutch is being used, which reduces the heat.
@iXiSWiiFTiXi yes...you hit the gas (with your heel) while breaking (with your toe)...hence heel and toe ;).a lil bit more is involved ie clutch, downshifting etc...but thats the jist of it...the purpose of heel and toe i think is to already b in the right gear when exiting a corner...but i would imagine it could be used for other stuff also, (maybe drifting...but idk) but if you are new to manual i really dont recommend using these techniques as they can do damage to your car if not done right
@joshGNR2 Now the reason it's used, and not just by americans, if because of the wear a clutch goes through. Some of you may know, and better than me, the clutch is merely a pressure plate that engages and disengages the engine from the transmission. Well while the clutch is separating the engine from the transmission, it's generating friction(heat and wear to the clutch plate). While it's minimal, certain irresponsibility, like locking ,or under-revving can cause the clutch to hear wear more.
you want to match the rev's while down shifting so you dont shock the drive train(meaning suddenly down shifting and the wheels locking up), you want to keep things as smooth as possible while going through turns at a high speed, and it also helps exiting the corner with the RPMs at the more peak area of your powerband
However, I found out that in a lot of cars u can actually simply press the clutch then rev up the engine, if the rmp is high enough, u can pass the gear guard and put the gear in place before u need to depress the clutch. This in turns saves time as it no longer requires u to switch to neutral and rev. correct me if i'm wrong though.
Reduces wear on components and makes shifts smoother. When the engine is not at the correct RPM (too low on a downshift) some of your car's momentum is used to spin the engine up to the correct RPM. This results in a very unpleasant jolt (basically it's braking the driven wheels) wich can result in a spin when cornering.
Don' confuse Heel and toe with double clutching. Heel and toe also reduces ransmission wear, it is easier to do and can be used in non-syncro transmissions... the idea is to equal transmission speed with engine speed (rpm). All race drivers and some street drivers use this technique. Dobule clutching consists of engaging the clutch to realse the current gear and then engaing it again to change gears while also accelerating in the same way as heel and toe to match trans speed with rpms
@Crossfire419 No, it is double clutching. Not once that I saw does he use the brake and accelerator at the same time, so it cannot be heel and toe. He does go into neutral and use the clutch twice for every gear change so it is double clutching.
The purpose of shifting like this is to prevent the wheels from breaking loose during the downshift (which can cause a spin), and to save the engine and drivetrain from shock loading (not a good thing). Use the brakes for their main purpose--to slow down.
The only way, to my knowledge, for the car to lunge FORWARD when downshifting is if you try to rev-match and you go over. If you're just letting the clutch out slowly without matching your revs there's no way the car is lunging forward, you would feel major resistance and slow down, especially going from 5th to 3rd.
The gearbox has an input shaft which is constantly meshed to a heavy countershaft. The countershaft is constantly meshed with every gear on the output shaft. In neutral all of the gears spin loose on the output shaft.
brake with the toe of the right foot disengage clutch with left foot rev with ball of right foot (still on the brakes) then engage the clutch again so that you can brake but still downshift while matching the revs
@cletedawgthewalmart Sounds right. I was just commenting on the fact that when I double clutch downshift (not necessarily during a heel and tow maneuver) the power is available right away when I release the clutch, but if I don't I feel it takes just a bit longer to get the power back. It makes sense right? By double-clutching, you match the revs before the final final clutch actuation, but when you don't, the synch takes care of it after clutch release.
i love that in fast and furious "granny shiftin not double clutchin' like ya should" oh because now we're racing 1929 detroit firetucks good one vin haha
The driver IS actually double clutching, yes he is 'heel and toe revmatching', however he is matching the revs with the clutch out and his gear stick in neutral. Which is called double clutching. Watch carefully that when he blips the throttle, his clutch pedal is actually up so obviously he will be in neutral, then he clutches again to get it into the lower gear. Current gear -> Clutch -> Neutral -> Blip/Revmatch -> Clutch -> Lower gear = Double clutch heel and toe, which is in this video.
@lunchbox3904 Correction, the engine needs to match the transmission. The Engine only has the potential for one gear, which spans it's RPM limits. The Transmission is what drives the car, and the engine drives the gears in the transmission. The different gears of a transmission are at different speeds, so the engine has to rev itself to correspond to the current gear's speed ratio(the gear speed to the engine speed, I mean)
@loodabeast NOPE he uses heel and toe to match the speed of engine and gearbox intake(conserves the clutch) and he uses double clutching to match speed between both gearbox shafts(conserves the synchro rings)
Basically what happens when you push the clutch in is it disconnects the flywheel from the transmission. If you're not pushing the clutch in all of the way on shifts, chances are you're burning up your clutch. For new drivers, without money, it's better to fully depress it. Right below the bite point should be fine but unless you racing there is really no need. Also when you come to a red light and it won't be changing soon fully depress the clutch. It's bad to sit there with it semi engaged.
Hey got a few questions for ya: 1. Is there any point double clutching on the road if your gearbox has synchro's? 2. When shifting down gears why would you release the clutch in neutral instead of keeping it on like you explained in your single clutch method? does the car rev differently when its in neutral? 3. Why doesnt this driver double clutch when he shifts up a gear?
Down Shifting DC is: clutch in, engage the neutral position, release clutch, blip gas, clutch in, engage next gear, clutch out. Up Shifting DC is: clutch in, neutral, clutch out, let the RPM drop, clutch in, select next gear, clutch out.
very good question. easiest answer, when you give it gas but have the clutch in, you are not making any contact with the gearbox. it is still a good question though
AccAkut1987: you're right but it can also make you faster in cornering. For example, if you were to take a corner in 3rd gear, clutch in+brake, now your engine is running slower (just a little cause you engaged the clutch) BUT if, at the time you engage the 2nd gear before accelerating, the speed of the engine is just a little slower than it should (for the car's speed), that's a slowdown you could have avoided by revving up the engine as you braked. Hope this helps !
you can actually shift up or down without using the clutch at all. on upshift liftoff the gas pedal, pull lever towards neutral, gingerly press it against next gear and when rev (drops) matches it goes in. on downsift liftoff, put in neutral, blip the pedal EXACT rev amount, lever gets in desired lower gear. expect a lot of damage on g/b though...
why not, he's saving his synchros... sure 1 clutch might cost more then 1 syncro, but repairing/replacing syncros on every gear cost more then replacing the clutch. Either way he's being more efficient with his driving. I still wonder why so many people keep thinking that just cause new cars nowadays have synchros, we SHOULDNT double de-clutch. The thing is, we SHOULD, but dont have to because the syncros are doing the work for us.
Now that's one good ass driver
Lets not forget the precision involved in the technique. Note how while blipping the throttle three times the pressure on the brake pedal is perfectly constant. This contributes to the smoothness of the down changes and progressive deceleration. Great stuff.
I love it that you think the type of car and the parts you bolt on somehow gives you driving ability and driving knowledge. Good for you!
That's right. Double-clutch downshifting is BENEFICIAL for ALL manual transmissions, but only NECESSARY in non-synchro transmissions. Clutchless shifting works for non-sychnro transmissions as well.
Thank you for showing everyone that you have no understanding of how synchros work. You've made my point for me.
To the people that say double-clutching takes longer and is slower, you are wrong. With double-clutching there is no time spent waiting for the synchros to match speeds, so the shift lever moves to the next lower gear with no resistance. Also, there is no need for faster downshifts as there is so much time in the braking zones, downshifts can be made almost leisurely.
That is some shifting skill. Gotta love how the aircon controls have been replaced with gauges =)
The driver lets in the clutch (releases) every time he blips the throttle. This is very important as not only do road speed and engine speed need synchrnonising but also the synchros in the gearbox. This prolongs the life of the synchros.Another subtle refinement to the technique is that the blip's duration be commensurate with the gaps in each gears ratio. Ie. close ratios--short blip,wide ratio--long blip. A pleasure when done right. A pleasure to watch. A pleasure to hear! Well done indeed.
Best heel n toe video on the internet !!
i never realized i drove that good till seeing this...this is how i drive my daily driver 5speed soch neon with full bult on...i shift/drive just like him.
OK, I'll ask myself. "Do you double-clutch, Gary?" "Why, yes I do, Gary, thanks for asking." "Why do you do that". "Well, because it completely eliminates synchro wear and doesn't take any additional time to do it." "Well then why doesn't everyone do it?" "Because some people learned one way and others learned another. It's personal preference, really. You don't HAVE to do it, but saving parts of the car at no expense in speed seems pretty smart to me!"
Now go ride your Bigwheel.
fre2fly...the smooth changes that double clutching provides help improve lap times in racing. It also saves on the gearbox.
Double clutching is not normally absolutely necessary on a street car, but it does save wear on the synchros in certain downshifting situations.
We had a recovery truck with a non syncro box you ether double clutched or it broke your wrist
thats what i call a proper shifting tutorial!
Hey, love seeing somebody else double clutch when downshifting. Makes the gear change so much easier. I'm a truck driver and of course use the technique when driving truck (if I even use the clutch lol) but now do it in my car too on the downshifts.
This guy has some amazing skill. He knows what kind of shift to perform for each situation.
What you described is Heel-toe Downshifting... Double-clutching is very useful. It allows you to engage your gears faster without putting extra stress on your synchros, once you have it down it is actually faster than not doing it.
winner! You're humor just flew right over their heads.
The concept is called rev matching in some magazine I read years back. Maybe Import Tuner or something. Rev matching is simply giving your engine some gas before you let the clutch out into gear so the engine speed is about the same as it would be in gear. The result is a smooth engagement and transition from gear to gear or neutral into gear. If you don't rev match you get that jerking feeling of near whiplash when your engine surges from 750rpms to 5,300 rpms.
i'm a truck driver and use the clutch sometimes. it depends on road conditions and the load you're pulling. when starting from a stop going uphill pulling 80,000 pounds, it makes sense to clutch it to be on the safe side. i also clutch on downshifts sometimes.
I like when he goes down three gears. So much work and such skill.
Wow, I love 0:18-0:20 and 2:10-2:13. That is some beautiful pedal work.
Driver has great technique and etiquette. Proper stuff, here.
The whole concept of Double-Clutching came about from racers during the early days of open-wheel racing. Back in the 20's when actual transmissions (or "gearboxes") were being used, most were three speed and had NO synchros. Therefore, the only way to get into the next gear (up or down) without losing much speed and w/o killing the gearbox, one would have to rev-match to allow a smooth and safe transition from one gear to the next.
Nice, accurate video of proper downshifting technique.
When you select any gear (except reverse) a soft brass synchro cup, which is splined to the output shaft, slides up against a cone on the side of the desired gear. The friction between the synchro brake and the gear cone matches the speed of the two until the synchro gear teeth can lock the desired gear to the output shaft.
this guy knows exactly what he's doing, proper piece of race kit and driving it properly without loading up the mechanicals unnecesarily.
It allows the engine to slow down so the transition into the next gear is much smoother. Basically instead of shifting into the next gear, you first shift to neutral. Rev match, and then clutch + shift into gear.
Most cars have synchros now, eliminating the need to match in everyday driving. But race cars (afaik) can get more power if they don't use a synchronizer.
On downshifts, clutch in, as the shift lever goes through neutral, the freely spinning gears will rapidly slow down and eventually even stop. As you try to slide the lever into a lower gear, that one gear's synchro brake works hard to spin the entire gear train up to the correct matching speed before the gear can be engaged and locked to the output shaft.
This technique is primarily used to smooth the transition of gear changes, primarily in rear wheel drive cars. It's not used to make the car slow down faster but this can be done with some car configurations (typically AWD platforms) but I wouldn't try that in to your Sunday driver. In drag racing you should be power shifting, and yes it's only needed for down shifts. This will make you quicker on a road course, yes, but only if done properly.
heel- toe, double clutch, rev match, all in a single video!
well said 70tKAWAn, perfectly explained the mechanics of d/c. yeah it took me 6 days to get a hang of it and like 2 weeks to do it naturally. the hardest thing was to overcome in you mind, that you're BRAKING and at the same time you actually press on gas pedal WHILE your clutch is UP. i found it was so weird at first and kept thinking my car will jerk that my left leg just refused to obey my order..
the old cars or entry level formula cars don't have synchrons in the gearbox so that by revving the engine with the clutch down it doesn't really spin the flyweel and you can't match the revs. Therefore, you have to clutch to realease the gear, let the clutch up, rev the engine then clutch down to enter the lower gear. You can also push the gear out while braking without clutching, then rev the engine and hit the clutch only once to enter the gear but the trani might not last as long.
it is called "blipping" the throttle. his right foot is applying the brakes to slow the car down, he is gassing the engine with his right heel to raise the RPMs then releasing the clutch when the RPMs match the road speed to the engine RPMs for the selected gear.
All I have to say is that's one sick driver and one sick sti.
Double clutching is a very good technique to know on high mileage vehicles, or transmissions that were not blessed with great synchro's to begin with. It will not hurt a synchromesh transmission, but it can lead to premature clutch failure. Shifting without the clutch is another story when it comes to the synchro trans.
Great example of braking whilst heel-toe double declutching. The 80's group B rally guys were the kings at it, check out some old skool rally vids if you wanna see quick heel-toe in action!
@mashimartin He's doing both. Heel-toe is used to apply throttle while breaking (obviously) He's using it to double clutch his downshifts while breaking so he has the least amount of breaking time to increase lap times and maintain control. Heel-toe can also be used to apply throttle while in gear, while breaking and counter steering to control a car in a slide (drifting.)
The output shaft always turns with the driven wheels as they are always joined by the driveshaft. The input shaft, the heavy countershaft, and all the other loose gears on the output shaft are all driven by the engine whenever the clutch pedal is released, or are all connected to and driven by the driveshaft whenever any gear is engaged with the gearshift lever. All that mass has a significant rotational inertia.
i too double-declutch heel&toe all the time. once you get used to it it's very useful. purpose of doing this is:
a)protect the syncromesh which after heavy use it starts to work less effectively therefore you do the syncro yourself - spin up the input shaft while you're in neutral and when the rev matches quickly clutch in and slot the gear in.
double clutching is useful for production car because normally a common everyday car has a gear guard. A gear guard prevents u downshift to a lower gear at high speed, as this is likely to damage the engine and gearbox. Many of you may have experienced that, u want to downshift(IE.3rd->2nd@45mph), though the car is pretty capable to run 50mph@2nd gear, u find it's stuck and u can't downshift to 2nd untill u slow the car to 25mph. Double clutch solves such problem.
Yep, that's Heal & Toe Downshifting. Search for it on here, there's plenty of videos.
The blip the throttle with their heal whilst braking with their toe to balance the vehicle, match the engine revs and it helps with quicker acceleration out of corners.
the quadruple clutching you demonstrated is impressive.
errpatrullero, at 18 seconds, count how many times my left knee goes up and down (six) and count how many gearchanges you hear (three). Two clutch throws for each gear = double-clutch. Watch the video again and you will also notice heel-toe downshifts. This is a video showing heel-toe double-clutch downshifts.
it eases the gear shift and helps match the RPMs better. there is not real point if you have synchros, they say it still works though. but Double declutching is mainly for cars without synchros, commercial trucks and motor cycles (cause its such a small ratio and pedal engaged throw, forcing a shift doesn't really matter)
un-synchronized gear boxes are used in race cars because they are lighter and they don't wear as bad as synchronized ones and also you can shift faster with this type of transmission. and double clutching is for keeping the revs up to the engine's max power range when downshifting
it reduces wear on your transmission by matching the engine speed with that of the gear you are shifting down to. Plus it makes for a smoother gear change because engine and transmission are more 'in sync'.
Again, this was a stock 5-spd Subaru gearbox with synchros, stock flywheel and stock clutch. Not a sequential gearbox.
Rev matching works best when in neutral, so you are actually spinning up the transmission. Getting the engine speed up is just part of the overall idea. When you are in neutral, the transmission is slowing down.
Also, over exagerated heel-toe blips do the same thing. The input shafts pilot bearing does create some drag on the shaft. By over blipping, you do the same thing as double-clutching.
Great video and excellent driving technique. Love the heel-toe brake with throttle blip. Nicely done!
I agree, but it is great for downshifting - smooth, fast, and much easier on the parts. I would say it is the only way to downshift unless the new lower gear would correspond to less than 1000 rpms
i wish i could drive like that that guys got some talent behind the wheel
@joshGNR2 To explain double clutching, you need to know about heel-toeing. This is a teqnique used while downshifting to: 1) prevent the locking of tires on a downshift, and 2) prevent over/under revving. When you go to brake, when you downshift, rather than just letting the clutch out, you give it some gas with your heel as you clutch out, to bring the revs up faster. This prevents the lock. Then you have an idea where your RPMs are at, and you will know if you need to go down another gear.
@cadillacdude1975 ...this way while you use your engine to reduce speed, you will prevent losing traction due to shift-lock when downshifting. It also will keep the car in balance while braking so you can brake almost until the apex without missing the line. Correct me if i'm wrong please.
@LT1HILLINGHOE You're right, there's no need to double clutch a synchronized transmission. The point of double clutching here isn't to keep the gears from grinding, but to prevent the lurch you get on a downshift by matching the engine RPMs, and retaining as even weight distribution as possible. This is how race drivers don't spin or lose time in corners. Drifters also use heel-toe control and double clutching to maintain control during a drift, another topic and application entirely, though.
rev-matching is not just average, if you ask me. But the difference is, if you rev-match with the clutch down you only speed up the parts up to the flywheel. If you shift in neutral and let the clutch out and then blip the gas, you speed up all the transmission parts involved. Less wear
I drive too....and it is Double clutching. And he is doing it right. It is hard for someone to see that if they don't know what they are looking for.
The double clutch just reduces wear on the synchros. You can single-clutch a heel-toe downshift, the synchros will just have to do a lot more work.
yes double clutching has little effect, but the heel-to-toe make your car drive a lot smoother and allows you to accelerate out of corners at a much faster rate, with more control because of the weight distribution is not all towards the front because of a harsher shift.
I would never double-clutch an upshift in a racecar as it would be a huge time waster. You will notice that I don't double-clutch the upshifts in the video. Double-clutching downshifts has nothing to do with keeping RPMs up or with keeping the boost up. It's about matching transmission input shaft speed to engine speed.
@surlograsp If you use your second example, the clutch spins way faster than the engine, and only single clutching wouldn't allow your clutch to slow down. Double clutching lets your clutch slow down, and rev matching (Throttle) makes your engine speed up. These combined will get your engine rpm and clutch rpm close, minimizing slippage when shifting, saving your clutch and syncros.
I know this is RUclips and a lot of users here like to throw around insults while hiding behind made up usernames, but I still don't appreciate being called an idiot.
This WRX racecar has an OEM transmission, clutch disc, pressure plate and flywheel. I double-clutch because it eliminates synchro wear. As one of the people responsible for rebuilding the transmission when it shits the bed, I like to reduce the number of times a season me and my crewmen need to crack it open.
almost sounds like a small displacement V8, Sounds Sweet!!!
double clutching was used in manycar racing series before synchros. Nowdays you really don't need to double clutch due to having synchros, just a propper downshift is all you need, all you trying to do is to match the revs of your motor and trans.
The primary purpose of this technique, as I understand it, is to help manage the BALANCE of the car when it is at the limits. Managing the weight balance of the car is paramount in high performance driving.
@Overdrive872
Actually he is double clutching as well if you look at his left foot on the downshifts. And it wasn't used only for trucks in the past. It's still used for all kinds of racecars without syncros and not solely trucks.
Heel-toe is actually more advanced than double clutching; it is double clutching, while braking. This is tough to do under light braking because tapping the throttle will usually cause you to tap the brake further as well. Heel-toe is really only useful for hard braking, and thus race driving since you won't likely be downshifting while hard-braking in traffic to avoid a wreck.
On a non-synchronized gearbox you need to let the clutch out in order to get the input rev speed to match the gear's movement when it meshes.
If you're rev-matched without double-clutching then you are rev-matching a synchronized transmission.
very smooth downshifts respect...!
The way he does it in the video is a little better than the way you described it in the last sentence. He's shifting into each gear on the way down which allows the transmission to be sped up by the syncros (which is bad as you said above but not as bad as going from say 5th gear to 2nd) but it's faster and safer since you're never in neutral.
@joshGNR2 When you heel toe, the process is: Let off gas, brake, clutch in, downshift, shift heel and gas, clutch out enough to bring the engine's revs to the transmissions gearing, and repeat all but the first two steps. Once you're at the desired speed/RPM, you let off the brakes, and clutch out fully, and begin acceleration. This is the basic rundown of heel-toeing. What double clutching does is shorten the amount of time that the clutch is being used, which reduces the heat.
@iXiSWiiFTiXi yes...you hit the gas (with your heel) while breaking (with your toe)...hence heel and toe ;).a lil bit more is involved ie clutch, downshifting etc...but thats the jist of it...the purpose of heel and toe i think is to already b in the right gear when exiting a corner...but i would imagine it could be used for other stuff also, (maybe drifting...but idk) but if you are new to manual i really dont recommend using these techniques as they can do damage to your car if not done right
@joshGNR2 Now the reason it's used, and not just by americans, if because of the wear a clutch goes through. Some of you may know, and better than me, the clutch is merely a pressure plate that engages and disengages the engine from the transmission. Well while the clutch is separating the engine from the transmission, it's generating friction(heat and wear to the clutch plate). While it's minimal, certain irresponsibility, like locking ,or under-revving can cause the clutch to hear wear more.
you want to match the rev's while down shifting so you dont shock the drive train(meaning suddenly down shifting and the wheels locking up), you want to keep things as smooth as possible while going through turns at a high speed, and it also helps exiting the corner with the RPMs at the more peak area of your powerband
However, I found out that in a lot of cars u can actually simply press the clutch then rev up the engine, if the rmp is high enough, u can pass the gear guard and put the gear in place before u need to depress the clutch. This in turns saves time as it no longer requires u to switch to neutral and rev. correct me if i'm wrong though.
Bloody hell this guy is good. Takes me about 5 seconds to complete a double clutch downshift at the moment :-D
Reduces wear on components and makes shifts smoother.
When the engine is not at the correct RPM (too low on a downshift) some of your car's momentum is used to spin the engine up to the correct RPM. This results in a very unpleasant jolt (basically it's braking the driven wheels) wich can result in a spin when cornering.
No, the input shaft slows down too. The, output shaft in the transmission is that only shaft within it that turns at the speed of the wheels.
Don' confuse Heel and toe with double clutching.
Heel and toe also reduces ransmission wear, it is easier to do and can be used in non-syncro transmissions... the idea is to equal transmission speed with engine speed (rpm). All race drivers and some street drivers use this technique.
Dobule clutching consists of engaging the clutch to realse the current gear and then engaing it again to change gears while also accelerating in the same way as heel and toe to match trans speed with rpms
@Crossfire419 No, it is double clutching. Not once that I saw does he use the brake and accelerator at the same time, so it cannot be heel and toe. He does go into neutral and use the clutch twice for every gear change so it is double clutching.
The purpose of shifting like this is to prevent the wheels from breaking loose during the downshift (which can cause a spin), and to save the engine and drivetrain from shock loading (not a good thing). Use the brakes for their main purpose--to slow down.
The only way, to my knowledge, for the car to lunge FORWARD when downshifting is if you try to rev-match and you go over.
If you're just letting the clutch out slowly without matching your revs there's no way the car is lunging forward, you would feel major resistance and slow down, especially going from 5th to 3rd.
The gearbox has an input shaft which is constantly meshed to a heavy countershaft. The countershaft is constantly meshed with every gear on the output shaft. In neutral all of the gears spin loose on the output shaft.
@cadillacdude1975 I think you are one of the very rare ppl on youtube who actually knows what they talk about. Cheers!
brake with the toe of the right foot
disengage clutch with left foot
rev with ball of right foot (still on the brakes)
then engage the clutch again
so that you can brake but still downshift while matching the revs
@cletedawgthewalmart Sounds right. I was just commenting on the fact that when I double clutch downshift (not necessarily during a heel and tow maneuver) the power is available right away when I release the clutch, but if I don't I feel it takes just a bit longer to get the power back.
It makes sense right? By double-clutching, you match the revs before the final final clutch actuation, but when you don't, the synch takes care of it after clutch release.
i love that in fast and furious
"granny shiftin not double clutchin' like ya should"
oh because now we're racing 1929 detroit firetucks
good one vin haha
The driver IS actually double clutching, yes he is 'heel and toe revmatching', however he is matching the revs with the clutch out and his gear stick in neutral. Which is called double clutching.
Watch carefully that when he blips the throttle, his clutch pedal is actually up so obviously he will be in neutral, then he clutches again to get it into the lower gear.
Current gear -> Clutch -> Neutral -> Blip/Revmatch -> Clutch -> Lower gear = Double clutch heel and toe, which is in this video.
@lunchbox3904 Correction, the engine needs to match the transmission. The Engine only has the potential for one gear, which spans it's RPM limits. The Transmission is what drives the car, and the engine drives the gears in the transmission. The different gears of a transmission are at different speeds, so the engine has to rev itself to correspond to the current gear's speed ratio(the gear speed to the engine speed, I mean)
@loodabeast
NOPE
he uses heel and toe to match the speed of engine and gearbox intake(conserves the clutch) and he uses double clutching to match speed between both gearbox shafts(conserves the synchro rings)
Basically what happens when you push the clutch in is it disconnects the flywheel from the transmission. If you're not pushing the clutch in all of the way on shifts, chances are you're burning up your clutch. For new drivers, without money, it's better to fully depress it. Right below the bite point should be fine but unless you racing there is really no need. Also when you come to a red light and it won't be changing soon fully depress the clutch. It's bad to sit there with it semi engaged.
Hey got a few questions for ya:
1. Is there any point double clutching on the road if your gearbox has synchro's?
2. When shifting down gears why would you release the clutch in neutral instead of keeping it on like you explained in your single clutch method? does the car rev differently when its in neutral?
3. Why doesnt this driver double clutch when he shifts up a gear?
Hahah. This is one skilled driver. Props to you!
Trying heel-toe'ing through the hills and it sure ain't easy!
Down Shifting DC is: clutch in, engage the neutral position, release clutch, blip gas, clutch in, engage next gear, clutch out.
Up Shifting DC is: clutch in, neutral, clutch out, let the RPM drop, clutch in, select next gear, clutch out.
very good question. easiest answer, when you give it gas but have the clutch in, you are not making any contact with the gearbox. it is still a good question though
AccAkut1987: you're right but it can also make you faster in cornering. For example, if you were to take a corner in 3rd gear, clutch in+brake, now your engine is running slower (just a little cause you engaged the clutch) BUT if, at the time you engage the 2nd gear before accelerating, the speed of the engine is just a little slower than it should (for the car's speed), that's a slowdown you could have avoided by revving up the engine as you braked. Hope this helps !
you can actually shift up or down without using the clutch at all. on upshift liftoff the gas pedal, pull lever towards neutral, gingerly press it against next gear and when rev (drops) matches it goes in. on downsift liftoff, put in neutral, blip the pedal EXACT rev amount, lever gets in desired lower gear.
expect a lot of damage on g/b though...
you said exactly what i just said just with more words. The only difference here is that I hope you guys can piece it together
why not, he's saving his synchros... sure 1 clutch might cost more then 1 syncro, but repairing/replacing syncros on every gear cost more then replacing the clutch. Either way he's being more efficient with his driving.
I still wonder why so many people keep thinking that just cause new cars nowadays have synchros, we SHOULDNT double de-clutch. The thing is, we SHOULD, but dont have to because the syncros are doing the work for us.