After putting it in D you put it in 2 for 2nd gear, and then shift all the way up to R for Race. After that if you want to go even faster you shift again to P for Plaid - if you want some information on how that works, there's a great documentary from the late 80s called Spaceballs that shows what happens when you do that.
What's granny shifting? I almost had this guy in an RX7 but he ended up beating me. When I was talking to him after the race he told me I was "granny shifting" and not double clutching like I should have been.
Great explanation! The only thing better after or before that description would have been a demonstration. Also, more about where this is useful with a modern synchro transmission; High RPM down shifts, while towing heavy loads, and on older transmissions with a worn synchro - you can stretch life before service if you’re willing and able to double clutch.
Nicely explained. I especially liked how you simplified things with a very basic drawing. Pop taught me the hows and whys of double clutching on a 1951 GMC pickup truck. It had the really low "creeper" gear as first gear. Later in life I got hooked on Triumph Spitfires. The Synchromesh components were all shot. Double clutching became natural. Learning this technique is a lifesaver for those folks with worn synchro's. Learn how to do it rather than spending thousands on a transmission rebuild.
Semi trucks don't have synchronizers. Double clutching is required to pass the CDL test, but 99% of the drivers I know, myself included, float through the gears without using the clutch at all. The only time I press my clutch is when I'm stopped.
+Xavier Kraśnicki nothing to be afraid of. If you're grinding, you're doing it wrong. When accelerating, it's pretty straight forward. Just bump it into the next gear, when the vehicle wants to be shifted. You'll find when the rpms are in the right range, the lever will fall right in. Downshifting is a little more involved, you have to bump the throttle up to get to the rpm range, and the lever will drop right in.
+wayne foutz I do the same thing. I surprised a new hire who rode with me one night. It was dark and he didn't know that I was shifting without the clutch until daylight. The look on his face...
Pretty nice. The only thing you left out is that you only have to let the clutch about half way out during the first release of the clutch peddle. No gear engaged, very little wear on the clutch, simply matching up spinning gears. Decades ago I visualized this as "an upshift into neutral" where you lead with the gas as if neutral is a higher forward gear while I was learning the technique. So double clutching can be thought of as "an upshift into neutral" between downshifts. Doing it all while doing perfect threshold braking with little more than the ball and big toe of your right foot is where all of the art occurs, of course.
Duca Moris hes going way to fast. His intention seems to be to prove he knows. @engineering explained ask yourself while you film if you were the audience would you understand yourself. People watching these vids don't know hence why they watch, and only a car pro can follow you at that speed of your information delivery.
But thats the benefit of a video. You can replay and pause it as often as you want. I tought his way of explaining and showing it with the graphics was pretty good.
Hooray at last someone who knows why you double de-clutch (as we call it in the UK). Most cheaper cars when I started driving had gate boxes with no syncro as did many lorry's (Trucks) then in the UK we moved to syncro on 3rd & 4th then 2nd 3rd & 4th and finally all forward gears. Good explanation EE
Seriously people, just rev match. You only have to double clutch when the synchro's are worn out. Rev matching already reduces synchro wear massively and it's what racing drivers use when downshifting (Heel toe)
+INFsleeper You should have probably noted that rev matching is to not upset the car when downshifting if you're driving at the limit (so, for racing drivers). (Professional) race car drivers get their equipment replaced often enough.
Rev matching doesn't reduce synchro wear at all. As soon as you press in the clutch Pedal and change gears, synchros will match speeds. It doesn't matter if you add throttle while the clutch is disengaged. Racedrivers are using heel and Toe to keep the car neutral while braking hard, reducing wear is not the reason for heel and toe. Double clutching is simply slower and race transmission don't need to last a long period of time.
+BerndvonBackstein It'll most likely make a small difference but I think people exaggerate wear of the synchro's a lot. But yeah racing drivers don't give a crap about wear
Nice to know, even though manual transmissions are a dying breed in America with about 2.7% of vehicles being sold with a real manual transmission-it was about 25% in 1995 (and similar numbers in Canada and Australia), and the ones that are still available have synchronized gears. Double clutching is useful to know for old vehicles or heavy trucks. Also a great anti-theft device as fewer and fewer drivers know how to use a clutch with each year that goes by.
8 years later and I’m trying to figure out for the life of me why double clutching doesn’t make sense. As a truck driver, I still couldn’t rap my head around why single clutching doesn’t work. Of course learning in a car first didn’t help. I needed visual reasons. And old reliable “Engineering explained” finally allowed my simple minded brain to comprehend the complexities of this concept. I cannot thank you enough. 🙏
I found that with floating, single clutching or double clutching, all require the driver to manually synchronize. This is something I discovered during my first month driving large trucks.
Concise, logical, linear, and easy to follow instructions. Thank you. Your choice to explain lesson vocabulary/terms prior to teaching the actual lesson increases overall comprehension and lesson success. Excellent Teaching Dr. E2!
Tractor Trailers have non synchronized transmissions, so he is right on this. You are the synchro. Non synchronized gears also makes it easier to float gears, especially when you get timing down.
I think it’s as simple as being In a higher gear, shifting to neutral, hit the gas in neutral then downshift, however i could very well be wrong and I don’t wanna actually try it until someone can confirm it 😂 don’t wanna blow out the clutch lol
Yup basically. Synchros wearing out is pretty uncommon. Back in the late 80's and early 90's my mom had a 1985 Toyota Carolla GTS with 280,000 miles on it, synchros were all fine. She got rid of it because holes rusted in the floor so she couldn't drive when it was raining.
+DarkHorizons Depends on the car, depends on the mileage. Wearing out synchros on a car with 100 or 150k is fairly common, more or less depending on the car.
Man you are genius... Just want to thank you for explaining us all those things.. I learn much about cars by watching your videos. BIG THANKS mate, you are the best..
+Engineering Explained yeah dude you explain perfectly!! you know someone really understands what he's saying when he can explain it in simple ways. bravo! keep it up
It's overexplained, really. Idk why he needed seven minutes to explain what Double Clutching is, and that it's almost completely pointless in your every day car, and mostly used in only tractor trailers. Push clutch in, shift to neutral, release clutch. Push clutch in, enter next gear, release clutch. Boom. Double Clutch complete. Don't confuse it with Dual Clutch.
These principles really came in useful when my throwout bearing went out and I needed to get my car to the shop without using the clutch. Pretty tough to do, but you can just barely blip the throttle to allow you to go into neutral, then either wait to shift (if you are upshifting) or rev match if you are downshifting. I was also lucky enough to have a car with a strong enough starter to start the car in first gear when I shut it down at lights.
Virtually every semi-truck, though virtually no truck driver double clutches. Should though, based on this video. Though a common counter-argument is that it wears out the clutch. Though I suppose a counter-counter-argument would be that it wears out the transmission if you don't.
A counter-counter-counter-counter-counter-counter-counter-counter-argument: you wear out your car when you drive it. Leave it in the garage and nothing will ever break.
spyro A well when you're hitting apex in a corner, you heel and toe to rev match into gear. so you will be in a good rpm power band and be quicker coming out of corners. In that heel toe process youre putting less wear on the syncros/trans
Question: While doing some research, there is a debate on whether it's necessary to shift into neutral, releasing the clutch pedal, and then depressing the clutch pedal before engaging the next gear VS. keeping the clutch pedal down the entire time. Which is right? Does it matter? Does it depend on if you have synchros? I think shifting into neutral makes sense because you can re-engage the clutch, having more parts move together. What do you think?
@@bobobibo2357yup, you can get away with not double clutching a light vehicle, but it will get progressively harder to do so as the synchros wear. On heavier vehicles, especially those with heavy transmission elements, you will have to double clutch to prevent premature wear. Heck, even on a light car, if you're doing some "spirited driving" you'll have to double clutch as it's much faster to change gears this way.
My stepfather drove my old Cavalier all the way to the auto shop with a busted synchronizer and I haven't known how for 16 years now. He is a commercial truck driver. Thanks so much for the video.
I don't understand why you have to let out the clutch in the middle, i simply press the clutch, match revs, let go of clutch, why put it in neutral? I didn't know double clutching was a thing but i started doing rev matching accidentally to make the ride smoother by intuition, so what's the difference between rev match and double clutch?
@@nhouston6179 old post. (3yrs) But upsifting you can still use dubble clutching. You go into neutral and rev match (let the rpm drop) and clutch + next gear. Less work for syncs as your already at the right rpm.
People are missing what gear speed is judging by comments. Maybe this guy can do a vid on that...imagine the gear speed is like your engine rpm: fast in third but slow in forth at a steady speed. So if you want to go back down to third you need to get third spinning fast again. Not "true" but its to the point. It is irrelevant with modern cars due to syncros but if you can grasp this relationship you can shift up or down without the clutch! If interested in shifting without the clutch: If what i said makes sence then recreate the situation and play with it to learn. This is not a one day look what i can do thing to learn so dont get in a rush at all. Corny to say but you will be devolping a deeper connection with you car and it won't happen overnight. First hold steady light throttle speed, hold throttle steady and you will find you can effortlessly pull it out of gear and put it right back into same gear, play with that a while. Next while driving normal ease off the gas slightly when you are getting close to time to shift and you will find you can pull it out of gear the same as before without the clutch, let off gas and put light steady pressure agaist the next gear and when the rpm is right it will let you into gear, move quickly when it invites you. Completely master upshifting before the next part, downshifting. Note that you will have mastered this when you feel like you just know what to do. It could be years before you are ready to downshift. Downshift is harder: Steady speed: Note what speed your tachometer says in third, shift to forth and note tachometer in forth. Without clutch push shifter into neutral, raise tach to the third gear number and it will effortlessly slip into third. Its easiest to go just past and while rpm is dropping catch the gear at the correct rpm. If you are still holding the same speed the you can go neutral to forth without clutch at the correct rpm. Practicing this 2 to 3rd or 3 to 4th is ideal, other gears are a little harder. Dont force anything, It should feel like it wants to do what you are asking of it. If you miss or grind just step on the clutch and get into normal gear. Anyone with a diesel will have a much much easier time learning this due to the operation of the diesel. You still need clutch to get going from a stop. If you dont grasp the idea of the gears spinning at their different speeds at different vehicle speeds then forget about it. Ive done it since i was 15 years old, 40 now, never broke a trans or wore out a clutch. I was lucky to learn with a diesel. 160,000 on my lancer that has been driven this way, no problems.
Double clutching is useless in any modern car, bc a syncronized transmission does exactly this for you. All you can do is clutch back in in time to match the rev while upshifting and rev match while downshifting, but no need to double clutch. Thats a myth that is never going to die. All it does is making you slower because you need more time. It also increases the risk of crashing because it needs a fuckton of concentration, you destroy your transmission while training.
I agree, it's overkill for masters of racing to get miliseconds while downshifting,otherwise a waste of time, and other parts of gear shifting system except clutch(pedal,spring,master and slave cylinder,push-bearing,etc..)
Agree. I've been double clutch downshifting since learning to drive from a fellow who drove everything from trucks to tractors to buses and it's made driving any car a hoot! All this effort trying convince people it's a waste of effort and concentration, is a bit over the top imo. Is DC necessary? nope. But in my world it puts the least amount of stress trans and syncros (and whatever else I don't know). BTW , the fellow who taught me all this, 42 years ago, still drives manuals as do I , and neither of us has ever had a trans or clutch wear out, even with some high milers. Each to his own and enjoy, be safe, and above all be courteous out there when whaling on your car and having fun!
inspectorchicken you need to do some research. modern car manual transmissions are junk. if you drive even somewhat spirited. the sycnros fail. for an example go look up a f23 or f35 transmission. they're know for weak syncros.
9th: Press the throttle. Very nice explanation, I've learned this in actual driving on my own (tho I never drive to any track yet) because I just want to eliminate that back drag when your shifting down gears so that you could go more smooth even your just driving in the city, more comfort while driving, comfort for the passenger as well in your car transmission. (didnt notice that I was doing already 9steps with this method till I watched this)
Even into the 1960s cars there were many cars like my brother's Mini Minor 850 that were sold with no synchro on 1st gear which is how I learnt to double-clutch! Knowing the technique is extremely useful to get you home or to the mechanic if your gearbox decides to play up on you!
Do you think it's worth mentioning how flywheel weight can affect this? If your flywheel is lightweight aluminum and you are shifting at lower rpms, then on upshifts you may have to blip the throttle.
this video probably has even more views because of people like me that every 6 months on the regular forgets how double clutching works, and rewatches the video
For all the people saying double-clutching is useless in a car with synchronizers, I respectfully disagree, particularly for downshifting. While downshifting can be a smidge slower since you have the pause in Neutral where you bump the layshaft up to speed, it makes less work for the synchronizers, which have to work hard to speed up the layshaft. It's usually not all that useful for upshifts, except has anyone driven their manual car in seriously cold weather where it just does. not. want. to. engage. any. gear? Double-clutch all of your shifts (especially between the first three gears), and magically the car will let you get into that next gear until the gearbox warms up and starts to behave again.
Yes, yes, yes, to all that. I had an old Subaru that in cold weather, needed double-clutching until the transmission oil warmed up. Also, I commonly drive a medium-duty truck (about 30,000 pounds GVW) that has a synchronized transmission, but when starting out cold, double clutching saves the day. And I can't tell you how many people I've met over the years who have worn out their first- and second-gear syncros in their cars by doing lots of downshifting into those gears "the standard way," and this could have been completely avoided by double-clutching, even if reserving that method for the more severe downshift situations. As to those who advocate floating the gears, that works, but with synchronized transmissions it's hard to tell if you are really doing it perfectly or not, and if not perfect, synchro wear is actually worse because the synchro clutch is rubbing for a time when the speeds on both sides of the unit are out of synch, but that extra friction accomplishes nothing since it can't cause the input shaft to change speeds in this case.
@@ericl2969 Actually cold weather is still an issue, I have a 2015 Subaru and while switching between the first three gears isn't impossible it is much easier if you double clutch until it warms up.
Was trying to get a faster acceleration in my old pickup to merge into 60mph traffic on a highway, from a dead stop on a side road. Figured out that if I only release the clutch about halfway when in first when applying the accelerator, then push it all the way in when shifting into second, I can save a fraction of a second compared to releasing the clutch all the way when in first, and also accelerate much faster because the RPM drop isn't as much. I call this "half-clutching". It makes no sense, probably isn't good for the clutch, but it sounds damn cool. If I tell the kids at work that I can professionally half-clutch in my truck, they're very impressed. They all drive automatic.
Sounds somewhat similar to a technique I've used that I call pulse-clutching while off-roading in an old low-horsepower VW dune buggy. I was trying to climb a very steep hill with deep ruts and boulders and my carb's main jet was clogged at the time, so I was basically feeding the engine unatomized gas from the accel. pump.. Needless to say, I wasn't making enough horsepower to complete the climb, so my technique was to put the clutch in and rev the engine up, pop the clutch to dump the momentum into the wheels, and then to repeat the process over and over until I was at the top of the hill. Really tough on the clutch and drivetrain, but it was certainly better than stalling out and having to back the thing down the hill in reverse.
I think I'm to tired to understand this video. Been driving standard cars and MC since I was 16yrs old for nearly 40 yrs now. I was tought to listen to the engine sound and shift up or down accordingly. Frictioning the clutch is what happens in traffic and chutch breaking correctly to slow down.
hmm if we're discussing transmission already. would you do a video on 'dog box transmission'? it's the transmission that was used in the original R32 Godzilla race car. and it seems to be a 'cheap'-ish way to 'upgrade' a transmission if you wanted to go serious racing
The lay shaft or cluster gear here is the culprit. It has to be matched to the speed of the desired gear being selected. This is done either by the synchro brass clutch in a synchro mesh transmission or by double clutching in neutral in a non synchro trans. Double clutching in a race car when approaching a corner saves the brass ring and allows the gear to be selected while braking (heel toe) so the corner can be exited quicker. On an old 60's 3 speed at a stop light in neutral (clutch out) with non synchro 1st gear, you had to put in the clutch and wait for the cluster gear to stop turning or there was clash. Putting the selector in 2nd first would stop the cluster then you could quickly select first.
Regarding a Corvette that I once owned, this explains why a chattering sound could be heard if the engine were to be shut down while in neutral and with the clutch pedal released - it was the winding down of the lay shaft that was making the sound. On the other hand, it was silent when shutting down the engine while in gear with the clutch pedal pressed (to the floor), which makes sense because the lay shaft wouldn't have been spinning immediately prior to shutdown (well, unless the vehicle was in motion, which it never was).
Heel and toe is when you're braking (perhaps into a corner), apply throttle to rev match the downshift. Only need to press the clutch once (assuming the car has synchros).
+nhilal94 Heel & toe is basically the double-clutching technique explained here, but while braking simultaneously. So you blip the throttle with the heel of your right foot (since the ball of the foot is pressing the brake pedal) instead of tapping it normally as described in this video.
If I downshift from 5th to 3rd because i want to overtake someone, can't I just press the clutch once, hold it in, go from 5th to 3rd, rev match, then release the clutch? I'm kinda new to stick shift.
In a manual non-synch transmission, when you double clutch, you only press the clutch down part way. The non-synch transmission has something called a "clutch brake" which is engaged when you press the clutch all the way down. The only times you would want to push the clutch all the way down was when stopped with the trans in neutral or sometimes when upshifting on an uphill. The reason for this is because with the clutch engaged, it is turning at engine RPM and you want it to stop turning so you can get it into a gear, since your wheels aren't turning.
I dont understand steps 3 and 4. Whats the point in matching the speed of the layshaft and the engine, if youre just gonna then match the layshaft's speed to the output shaft right after that? Why dont u just skip neutral by shifting from 3 to 4, rev the engine to match rpm and then release clutch? Cuz then the layshaft and output shaft would be the same speed already, and you just have to match the engine to the rest. Im a noob here so i dont get it
Double clutching is only needed in an unsynchronized transmission. You see the blue gears on his whiteboard? In a modern car they are all always connected and spinning together and we connect to individual gears with synchronizing rings and the drive shaft sleeve (the black marker on the whiteboard). In a sliding mesh transmission you have to move the blue gears into the teeth individually since they are not connected until you slide them in when you want that gear and having to match the gear speeds perfectly to get them in. Really easy to grind that way which is why we got away from it. So to answer your question, there is no point to matching the gear speeds of the lay shaft, maybe you get marginally less wear on the synchro rings but really I'd say it's negligible.
i always assumed double clutching was a technique used to go faster in a race or just in general. am i correct in now assuming it's just how you change gears in a shotty car?
+tumatauenga You might be thinking more about heal and toe shifting rather than double clutching, which does help to speed up manual shifts and therefore keep you on the power more effectively.
+tumatauenga No, takes more time because you have to press the clutch twice per shift. You only need it in semi's or older transmissions or if your synchros are worn out. It's never an advantage to have to do this, lol.
Loki Jotunn i'm just speculating because of fast and furious it's always bothered me cause i have no idea what it is or why you would do it. whats heal toe shifting?
+Tomas Prado Rev matching involves pressing the accelerator enough to get the engine RPMs to spin at a rate to match the rotation of the driveshaft. The synchro gears that are part of the gears in the manual transmission box help those gears rotate with the driveshaft as you move the stick into gear. So the driveshaft and the transmission gear are rotating at the same rate. When you release the clutch and the flywheel engages with the transmission gear (through the countershaft), you'll want the engine RPMs to match as closely as possible. With double clutching, you're lining up the engine with the transmission gears first by releasing the clutch while the transmission is in neutral. Then you want to adjust the RPMs of the engine (and because the clutch is released, the transmission as well) with the driveshaft rotation before moving the stick into the gear you're selecting. This will help the transmission gear and the driveshaft mesh together with less wear. Since the engine RPMs will be rotating at a similar rate when you release the clutch the second time the transfer of power should be smoother. The essential difference is that rev matching is about getting the engine RPMs to match the driveshaft rotation while double clutching has the added step of using the engine to adjust the transmission gear rotation to ease the meshing with the driveshaft because there are no synchro gears effectively doing it for you.
+Tomas Prado Rev matching is essentially the same thing, except the clutch is disengaged from the engine, and thus all the load of "synchronizing" upon contact is placed on the clutch, not the synchros themselves. When the car is in neutral, your clutch is mashed to the flywheel, and thus all your gears will spin with the engine speed, they just won't be connected to the output shaft. With rev matching, your clutch is away from the flywheel and your gears and spinning at wheel speed, not engine speed. For example; my 2nd gear synchro on my STi is slightly worn out, and at high RPMs tends to grind a bit. When downshifting from 3rd to 2nd, it's easier for me to double clutch and synchronize the gears with the engine than it is for me to rev match and engage the clutch quickly enough to both 1) keep the momentum, and 2) not wear out the clutch and throwout bearing. It's hard to explain without a moving diagram or animation, but hopefully my explanation and Jason's diagram can help.
+Bernie Lee that actually did help thanks but the double clutch that I learned..."in the racing world" is when you push in the clutch for a fraction of a second while accelerating to raise the rpm level and then you release the clutch while it is still in gear so the engine will pull at a higher rpm then when you initially engaged the clutch
This is a very good explanation,however, many fail to understand why it is a good thing even with synchronised boxes - if you listen when changing without doubling you can hear the gears spinning up, this is exactly what the synchro hub does, however, if you wish to take the wear off the synchro hub doubling will match the gears and take some of the wear off the hub and it will change quicker and smoother too.
Why do semi-trucks do not have synchros in their transmissions? (i.e. Eaton Fuller 10, 18 spd) Also, how does hill holding circuit work without waring out the components? Great videos!
Semi's don't have synchros because they wouldn't last. With the torque a big rig engine puts out and the heavy loads they carry, the synchros would ware out very fast and would have to be replaced very frequently. VERY UNECONOMICAL.
From the ZF brochure from Europe: ■ Thanks to its wide torque range, the Ecosplit synchromesh transmission gets by with twelve or sixteen gear steps. A light metal alloy housing saves unnecessary weight, and the helical gears allow for quiet running. Shorttravel and dual cone synchronizers as well as the Servoshift unit reduce shift forces and paths. The transmissions of the Ecosplit range, equipped with an integrated bell housing, are available in a wide product range for all truck applications up to 44 tons of total weight. ZF has already proven that is not true for European trucks.
Well, yes, but if you wait a bit for the rpm of the clutch to drop, it won't be much different. More wear if you do it just as quickly as you would shifting to third.
+Engineering Explained also i think that depends alot on gear ratios, my vw and audi both have close ratio transmissions and i if I'm really on it I skip 2nd at least and sometimes 4th
Double clutching helps if your trans has worn synchros. Like mine. And it sounds cool with a nice exhaust. Like mine. Best double clutching movie ever you ask? That's the original bullett movie. That's double double clutching if you listen carefully. 😳 Be like that and you are the man..
Thanks. always wondered why you would do it. I learned the day I bought my 06 Hyundai Tiburon. I told the lady selling it that if she wanted me to buy that car that day, she had to teach me standard. She sort of did and I learned the rest. Funnest and scariest two week of stalling and learning of my life. But now I love stick and never want to go back.
I usually double clutch the lower gears and then go to floating around 5th on the 18 speed. If I'm downshifting I usually left foot brake and blip throttle with my right while floating down, letting the engine brake do most the work. It's easy to tell if I get the rev match wrong because the 10k gallons of fuel surges forward in the tanks lol
I have never understood why someone would do this? Just feather the gas and keep the revs up. Unless you are driving a split rear end or heavy truck with a non synchro transmission you are just wearing out your clutch.
There's virtually no extra wear on the clutch because there is no load on the input shaft during that extra engagement. You will never wear out your clutch from double-clutching, but on the other hand, downshifting the normal way will eventually wear out the synchros if you keep your car long enough, especially resulting from high-rev downshifts. I've seen quite a few cars with totally blown synchros on 1st and 2nd gears. It's not rare at all, and double-clutching to minimize that wear during the most wear-inducing kinds of downshifts isn't such a bad idea.
@@ericl2969 Hello, I just bought a 2012 WRX with 84,000 miles on it and noticed some grinding going from 1st to 2nd. Figured it had to do something with the synchro, but not quite sure exactly. It works fine when double clutching and shifting slower, however. The other gears have no problem shifting.
@@kylewininger6824 definitely syncros, and you should let the throttle burn out when upshifting for smooth shift, also double clutch when downshifting to minimize wear.
@@Matthew-ev4cv as if the clutch is inoperable. When gearing up, 1st to 2nd gear you have to let the engine speed slow down a little, to allow the gears in the transmission to match speeds on the main shaft and the layshaft in order for them to mesh. Conversely, when gearing down the engine speed has to be raised to match the gear speeds so that they can mesh. This is where the engine tach is important as it does help a lot. Most transmissions on trucks have a 500rpm difference between gears and if it has a splitter it will be 250rpm. That's the basic principal, practice is the key, don't get rammy with it, after a while you can feel what is going in the transmission. Hope this helps, if you have any questions get back to me. Best wishes and good luck. Martin.
@@imthedarknight-8755 haha my mothers valves I was a learner at the time, now if I double clutch its only from 5th to 4th. So guess I learned my lesson
+Rainer67059 I understand. And roughly what era are we talking about? I'm 29 and fascinated with all things with engines, only in the "referenced" movie, did I first hear it. Was this required for all cars/trucks before a certain year?
+Rainer67059 I understand. And roughly what era are we talking about? I'm 29 and fascinated with all things with engines, only in the "referenced" movie, did I first hear it. Was this required for all cars/trucks before a certain year?
+Rohan Thatté In America the end of this era began in 1936. The car industry introduced this new transmission in 1936. It ended I think, exactly then. But trucks and busses may have had non-sync transmissions for longer. The 1934 La Traction Avant by Citroen was the first car to have a fully synchronized transmission. Although this technology originated in Europe, its success was faster in America. My father told me to have to apply the technique on his early cars. He started motoring with a Vespa in the 1950s.
This pretty much confirms the 4th gear synchro in my Subaru Legacy is dead. Almost always grinds/crunches when going into 4th gear, up or down. Recently I experimented with double clutching up shifts and down shifts and it almost never crunches when doing it this way. 4th is the only gear with the problem. Great video.
My old man has been driving an old truck like that for over 10 years. To this day, with multiple operators, he is the only one that can down shift without grinding. Old skool gear box with no synchro and you can listen to him rev the engine to get everything turning at the right speed.
Question regarding trucks -I was instructed NOT to double clutch when driving a old Volvo truck, why is that? I was double clutching which seemed to help with its slightly difficult gearbox. Thanks for excellent brisk tutorials, giving reasons why.
I learned to drive in a 1949 Ford 1 ton truck. It was necessary to double clutch because the transmission did not have any synchros because that's how it was built. Also, 1st gear was meant for very heavy loads and was called the "Compound gear". Without a load in the truck 2nd gear was used to get going.
I am a big rig driver and I use this method all the time particularly with down shifting. Timing is everything! I have witnessed new drivers trying this and will grind an Eaton Fuller ten speed transmission to powder if they don't get it right.
Fast and Furious fans always talking about double clutching and more than half of them don't even know what that is... I'm so sick of FaF fanboys, they are everywhere..
When my dad taught me to drive he taught me how to change gears in a standard transmission. I learned how to double clutch then later I learned how to float the gears which is a way to shift without using the clutch at all. After that I only had to use the clutch when I had to stop, start from a stop, or reverse. Haven’t driven a standard transmission for years but I bet I could still float the gears. It might be a little sloppy for a bit but who knows until I get a chance to try. In this day and age finding a standard transmission would be harder than floating gears.
J Silk,the reason for double clutching is to get it in gear.I have to double clutch in my car when down shifting to first because it is an unsynchronized gear.
Nope, you're wrong dude. I've driven Model T's; MGs and Austin's from the 60s.. It's all about the delay for the gears and clutch plate to sync ... nothing more. you could go for a drive right now, put you foot on the clutch and hold it there as you count to two Mississippi and then switch gears - no grinding gears, no problems at all.
Hmm I drive a 11’ jumbo transit van and I definitely need to double clutch between gears 1-3. A lot smoother transition when I do so, syncros are probably a bit worn after years of carrying a lot of weight. Informative video none the less
Bro, seriously...? If you are a real driver, you can change the gears in a fraction of a second. That means the engine doesn't even have time to breathe, much less come down in RPM. So the double clutching thing sort of feels like unnecessary time waste and a delicate conscious effort while changing gear every time. Because I almost always change gears sub-consciously within half a second. Double clutching would take years to change a gear. LOL
IF, and its a big IF, you are really good you only have to use the clutch to initially engage first gear when starting from a stop and do not have to disengage it till you stop again. The problem is this can cause damage if you are not really good at matching the engine speed to the ground speed for the gear you want. With synchronizers you can gently feel when to engage the gears. I have driven home a couple times with a broken clutch linkage. shut engine off to stop after slipping trans out of gear as you coast down. with engine stopped put trans in first. use starter to get going and just shift carefully. I never broke or ground the gears etc. There are things you can do sometimes that work if you think about it.
This is more related with synchronizers: In Sweden, rev matching is not taught at driving schools but merely something you have to learn on your own. I don't do it, but I'm thinking about learning it. For me, there are two alternatives to get the downshifting smooth then; Assume I need two change down to 2nd gear before a curve coming in around 32 km/h, I hit the brake gently, change down to 2nd and then release clutch to biting point and keep it very gently there. You'll see the engine starts to brake for you, and when it's done; foot is off the clutch and the speed should be about 18-24 km/h. Or I use the brake more "harder" and shift down when the speed is about right. Both cases are completed before turning. The car is always smooth. But I assume I'll have less wear if I rev match?
the action of pushing in the clutch actually means the clutch is disengaged which is why having the clutch pressed down is essentially having the car in neutral I think. The action of taking your foot off the clutch when in gear means the clutch is engaged to actually drive it so that it's not in "neutral" anymore.
Had to do it in my second vehicle, 41 military 1/2 ton closed cab pickup. Straight cut gears with granny low 4 speed. Took a bit to learn the idea but once I had it down it was very easy to shift up or down. Sometimes I could even shift up without using the clutch going up on a good day. Very tough transmissions in those old Dodges, only saw one with a broken tooth and it still worked, just clanked when it hit the missing tooth.
I learnt about double declutching when I learnt to drive (and non synchromesh gearboxes were still relatively common in older trucks), but was never actually taught it. I used it on one of the works vans when the synchromesh failed for 2nd gear, and despite my being the youngest driver there, was the only one not to crunch 2nd in that van.
I’m confused, what do I do after I put it in D?
There is no D here
Pro Amateurs lololololololololololololololololololololol
After putting it in D you put it in 2 for 2nd gear, and then shift all the way up to R for Race. After that if you want to go even faster you shift again to P for Plaid - if you want some information on how that works, there's a great documentary from the late 80s called Spaceballs that shows what happens when you do that.
heil hooter as soon as i saw plaid i knew it would be a spaceballs reference lol
lolololololololol
This wizard is very good at showing his spellbooks and sharing his magics.
This is just great.
Any suffitiantly advanced technology is indistinguishable from magic
😂
why i cant see the scar on his forehead?
He must have hide it!
Yes
you lost me at release accelerator.
+The Big Potato You must hold on just a little bit longer Big Potato!
The Big Potato boobs.
after releasing accelerator, you go brahhhhhh, stutututtuut, brahhhhh.... stututututut.... and brake.
No more clutch... ftw? He just released a video on that XDDDD
@cicatriz ! you don't wanna strip the ⚙ gear-shaft my bro , while maintaining engine power
why do i think he is like 15 and 45 at the same time
kuk
St gT because he has ligma .
What's ligma?
Иван Боровков Ligma balls
OHHHHHHHHHHHHHHHH MY GOD REALLY?
The fact that this guy doesn't beg for subscribers makes him more deserving of it
I used to double clutch in my old golf for fun. Really interesting video!
Deffinatly did not expect to find you here.
+Mumbo Jumbo mumbo has had a golf confirmed! :P Now try clutchless shifting ;)
+Mumbo Jumbo What? I literally just came here from watching a few of your videos.. lol
Min blown Mumbo! What's up!
mumbo(: glad to see you here! manual ftw
What's granny shifting? I almost had this guy in an RX7 but he ended up beating me. When I was talking to him after the race he told me I was "granny shifting" and not double clutching like I should have been.
you need more nos
Arvin Singh I heard that'll make your floor fly out from under your car...
+Hot Rod Lincoln that means you didnt keep on power between the gears, great way to daily drive not best sstrat to win races
+Hot Rod Lincoln Who needs to double clutch when you can POWER SHIFT for the win!
+Hot Rod Lincoln You never had him. You never had your car.
quadruple clutching is where its at, you need super swift kicks to do it. Kind of like Chun Li (street fighter) with her swift kicks! hya ya ya ya!
Cr4zy Goose not funny at all
except 50+ thought it was
I think we all know who Chun li is.
@@Kidsvids82 it was hilarious
@@lgbtbathroom5562 yicu
Great explanation! The only thing better after or before that description would have been a demonstration. Also, more about where this is useful with a modern synchro transmission; High RPM down shifts, while towing heavy loads, and on older transmissions with a worn synchro - you can stretch life before service if you’re willing and able to double clutch.
"Granny shifting and not double clutching like you should"
I knew this comment was in here somewhere
@@zomble5gaming746 I swear, that line pops into my head every single time I hear the words "double clutch."
The fast and the furious dialogue
Lmao just saw that comment on a 370z fb group😂
incredible film
Nicely explained. I especially liked how you simplified things with a very basic drawing. Pop taught me the hows and whys of double clutching on a 1951 GMC pickup truck. It had the really low "creeper" gear as first gear. Later in life I got hooked on Triumph Spitfires. The Synchromesh components were all shot. Double clutching became natural. Learning this technique is a lifesaver for those folks with worn synchro's. Learn how to do it rather than spending thousands on a transmission rebuild.
Semi trucks don't have synchronizers. Double clutching is required to pass the CDL test, but 99% of the drivers I know, myself included, float through the gears without using the clutch at all. The only time I press my clutch is when I'm stopped.
I usually float when driving passenger cars too. It's not hard after you get the hang of it.
+wayne foutz I'd like to learn this but I'm too scared and not rich enough to try ; )
+Xavier Kraśnicki nothing to be afraid of. If you're grinding, you're doing it wrong. When accelerating, it's pretty straight forward. Just bump it into the next gear, when the vehicle wants to be shifted. You'll find when the rpms are in the right range, the lever will fall right in. Downshifting is a little more involved, you have to bump the throttle up to get to the rpm range, and the lever will drop right in.
+wayne foutz I learned it from my gradfather back in the day :P
Still a lot of fun, when friends are in the car and they wonder wtf I am doing ^^
+wayne foutz I do the same thing. I surprised a new hire who rode with me one night. It was dark and he didn't know that I was shifting without the clutch until daylight. The look on his face...
Pretty nice. The only thing you left out is that you only have to let the clutch about half way out during the first release of the clutch peddle. No gear engaged, very little wear on the clutch, simply matching up spinning gears. Decades ago I visualized this as "an upshift into neutral" where you lead with the gas as if neutral is a higher forward gear while I was learning the technique. So double clutching can be thought of as "an upshift into neutral" between downshifts. Doing it all while doing perfect threshold braking with little more than the ball and big toe of your right foot is where all of the art occurs, of course.
Hopefully i'm not the only one who didn't catch any of that....
Duca Moris I was able to follow. I could explain a certain part if it was confusing.
Duca Moris hes going way to fast. His intention seems to be to prove he knows. @engineering explained ask yourself while you film if you were the audience would you understand yourself. People watching these vids don't know hence why they watch, and only a car pro can follow you at that speed of your information delivery.
But thats the benefit of a video. You can replay and pause it as often as you want. I tought his way of explaining and showing it with the graphics was pretty good.
try bumping the video up to double speed, for me it's like he suddenly starts speaking english and I can follow along
I don't know what he's selling but I didn't get any of it 😟
Hooray at last someone who knows why you double de-clutch (as we call it in the UK).
Most cheaper cars when I started driving had gate boxes with no syncro as did many lorry's (Trucks) then in the UK we moved to syncro on 3rd & 4th then 2nd 3rd & 4th and finally all forward gears.
Good explanation EE
Seriously people, just rev match. You only have to double clutch when the synchro's are worn out. Rev matching already reduces synchro wear massively and it's what racing drivers use when downshifting (Heel toe)
+INFsleeper
You should have probably noted that rev matching is to not upset the car when downshifting if you're driving at the limit (so, for racing drivers). (Professional) race car drivers get their equipment replaced often enough.
+Nee het is steen and why does it not upset it? because it's not engine braking. That reduces synchro wear :)
Rev matching doesn't reduce synchro wear at all. As soon as you press in the clutch Pedal and change gears, synchros will match speeds.
It doesn't matter if you add throttle while the clutch is disengaged.
Racedrivers are using heel and Toe to keep the car neutral while braking hard, reducing wear is not the reason for heel and toe. Double clutching is simply slower and race transmission don't need to last a long period of time.
+INFsleeper
+BerndvonBackstein It'll most likely make a small difference but I think people exaggerate wear of the synchro's a lot. But yeah racing drivers don't give a crap about wear
I cane here just to read the fast and furious references.
wasn't disappointed.
I NEVER NARKED ON NOBODY!!!!!
+Brandon Bromley lmbo
Jessie you should be going to MIT or something man
Came *
Nice to know, even though manual transmissions are a dying breed in America with about 2.7% of vehicles being sold with a real manual transmission-it was about 25% in 1995 (and similar numbers in Canada and Australia), and the ones that are still available have synchronized gears. Double clutching is useful to know for old vehicles or heavy trucks. Also a great anti-theft device as fewer and fewer drivers know how to use a clutch with each year that goes by.
8 years later and I’m trying to figure out for the life of me why double clutching doesn’t make sense. As a truck driver, I still couldn’t rap my head around why single clutching doesn’t work. Of course learning in a car first didn’t help. I needed visual reasons. And old reliable “Engineering explained” finally allowed my simple minded brain to comprehend the complexities of this concept. I cannot thank you enough. 🙏
Here I am thinking at some point he’s actually going to get in a car and drive
austin hendricks and there’s me thinking he wasn’t going to be monotonous
I found that with floating, single clutching or double clutching, all require the driver to manually synchronize. This is something I discovered during my first month driving large trucks.
Right! So then all you're doing is more work for no reason. Just learn to float gears
Concise, logical, linear, and easy to follow instructions. Thank you.
Your choice to explain lesson vocabulary/terms prior to teaching the actual lesson increases overall comprehension and lesson success.
Excellent Teaching Dr. E2!
I think I have been unintentionally double clutching the entire time...
Some people also call it : clutching very slow. Needless to say, that is a bad thing.
Like you should
Tractor Trailers have non synchronized transmissions, so he is right on this. You are the synchro. Non synchronized gears also makes it easier to float gears, especially when you get timing down.
I did not even understand what I did not understand 😑
That's deep
i acquired an aneurysm
Utkarsh Adhikari i gave up listening after like 2 minutes
@@gsainoy i suffered a loss of brain cells.
I think it’s as simple as being In a higher gear, shifting to neutral, hit the gas in neutral then downshift, however i could very well be wrong and I don’t wanna actually try it until someone can confirm it 😂 don’t wanna blow out the clutch lol
so basically double clutching a waste of time.
Unless you wear out your syncros like he said.
Yup basically. Synchros wearing out is pretty uncommon. Back in the late 80's and early 90's my mom had a 1985 Toyota Carolla GTS with 280,000 miles on it, synchros were all fine. She got rid of it because holes rusted in the floor so she couldn't drive when it was raining.
+DarkHorizons Depends on the car, depends on the mileage. Wearing out synchros on a car with 100 or 150k is fairly common, more or less depending on the car.
+DarkHorizons Mine are worn. Its a 07 honda civic 213k miles.....
+MrSlowestD16 More or less depending on who drives the car.
Man you are genius... Just want to thank you for explaining us all those things.. I learn much about cars by watching your videos. BIG THANKS mate, you are the best..
+burazengija appreciate the kind words, thanks for watching! :)
He is like an American Ryosuke
+SheepShaving OMFG so true... initial d is lyfe
+Engineering Explained yeah dude you explain perfectly!! you know someone really understands what he's saying when he can explain it in simple ways. bravo! keep it up
It's overexplained, really. Idk why he needed seven minutes to explain what Double Clutching is, and that it's almost completely pointless in your every day car, and mostly used in only tractor trailers. Push clutch in, shift to neutral, release clutch. Push clutch in, enter next gear, release clutch. Boom. Double Clutch complete.
Don't confuse it with Dual Clutch.
I was completely lost at 0:01
These principles really came in useful when my throwout bearing went out and I needed to get my car to the shop without using the clutch. Pretty tough to do, but you can just barely blip the throttle to allow you to go into neutral, then either wait to shift (if you are upshifting) or rev match if you are downshifting. I was also lucky enough to have a car with a strong enough starter to start the car in first gear when I shut it down at lights.
That sounds kinda nerve-wracking😳
@@code0662 it was, but I got the vehicle there. Had to go on the road all week or would have fixed it myself. All is well that ends well.
@@inultus1 absolute Madlad. You've earned my respect
Rolling it on in 1st gear would‘ve also been an alternative on weaker engines. Just need a couple of strong lads.
Virtually every semi-truck, though virtually no truck driver double clutches. Should though, based on this video. Though a common counter-argument is that it wears out the clutch. Though I suppose a counter-counter-argument would be that it wears out the transmission if you don't.
A counter-counter-counter-counter-counter-counter-counter-counter-argument: you wear out your car when you drive it. Leave it in the garage and nothing will ever break.
Works well when you've killed the 2nd gear synchro ;)
we was using this when i was street racing. never thought i would watch a video of someone explaining it scientifically
i thought it was giving us more push on the next gear or something, i guess we was wrong
+spyro A you streatracer?
spyro A well when you're hitting apex in a corner, you heel and toe to rev match into gear. so you will be in a good rpm power band and be quicker coming out of corners. In that heel toe process youre putting less wear on the syncros/trans
what kind of car?
smminco nissan nx
Question: While doing some research, there is a debate on whether it's necessary to shift into neutral, releasing the clutch pedal, and then depressing the clutch pedal before engaging the next gear VS. keeping the clutch pedal down the entire time. Which is right? Does it matter? Does it depend on if you have synchros? I think shifting into neutral makes sense because you can re-engage the clutch, having more parts move together. What do you think?
must clutch twice if u want a smooth shift and dont wanna wear out the syncs
@@bobobibo2357yup, you can get away with not double clutching a light vehicle, but it will get progressively harder to do so as the synchros wear. On heavier vehicles, especially those with heavy transmission elements, you will have to double clutch to prevent premature wear. Heck, even on a light car, if you're doing some "spirited driving" you'll have to double clutch as it's much faster to change gears this way.
My stepfather drove my old Cavalier all the way to the auto shop with a busted synchronizer and I haven't known how for 16 years now. He is a commercial truck driver. Thanks so much for the video.
I don't understand why you have to let out the clutch in the middle, i simply press the clutch, match revs, let go of clutch, why put it in neutral?
I didn't know double clutching was a thing but i started doing rev matching accidentally to make the ride smoother by intuition, so what's the difference between rev match and double clutch?
Aaaaahhhhh so "maybe" I can use this in my 74 Beetle, which crunches when you shift 2nd to 3rd unless you shift really slowly.
not really going to help going up gears from 2-3 its more for 3-2.
@@nhouston6179 old post. (3yrs) But upsifting you can still use dubble clutching. You go into neutral and rev match (let the rpm drop) and clutch + next gear. Less work for syncs as your already at the right rpm.
Diner50 Yeah it seems like it might help as it sounds like he just has worn synchros, that's why he has to shift slowly
People are missing what gear speed is judging by comments. Maybe this guy can do a vid on that...imagine the gear speed is like your engine rpm: fast in third but slow in forth at a steady speed. So if you want to go back down to third you need to get third spinning fast again. Not "true" but its to the point.
It is irrelevant with modern cars due to syncros but if you can grasp this relationship you can shift up or down without the clutch!
If interested in shifting without the clutch: If what i said makes sence then recreate the situation and play with it to learn. This is not a one day look what i can do thing to learn so dont get in a rush at all. Corny to say but you will be devolping a deeper connection with you car and it won't happen overnight. First hold steady light throttle speed, hold throttle steady and you will find you can effortlessly pull it out of gear and put it right back into same gear, play with that a while. Next while driving normal ease off the gas slightly when you are getting close to time to shift and you will find you can pull it out of gear the same as before without the clutch, let off gas and put light steady pressure agaist the next gear and when the rpm is right it will let you into gear, move quickly when it invites you. Completely master upshifting before the next part, downshifting. Note that you will have mastered this when you feel like you just know what to do. It could be years before you are ready to downshift. Downshift is harder: Steady speed: Note what speed your tachometer says in third, shift to forth and note tachometer in forth. Without clutch push shifter into neutral, raise tach to the third gear number and it will effortlessly slip into third. Its easiest to go just past and while rpm is dropping catch the gear at the correct rpm. If you are still holding the same speed the you can go neutral to forth without clutch at the correct rpm. Practicing this 2 to 3rd or 3 to 4th is ideal, other gears are a little harder. Dont force anything, It should feel like it wants to do what you are asking of it. If you miss or grind just step on the clutch and get into normal gear.
Anyone with a diesel will have a much much easier time learning this due to the operation of the diesel. You still need clutch to get going from a stop. If you dont grasp the idea of the gears spinning at their different speeds at different vehicle speeds then forget about it. Ive done it since i was 15 years old, 40 now, never broke a trans or wore out a clutch. I was lucky to learn with a diesel. 160,000 on my lancer that has been driven this way, no problems.
Double clutching is useless in any modern car, bc a syncronized transmission does exactly this for you. All you can do is clutch back in in time to match the rev while upshifting and rev match while downshifting, but no need to double clutch. Thats a myth that is never going to die. All it does is making you slower because you need more time. It also increases the risk of crashing because it needs a fuckton of concentration, you destroy your transmission while training.
I agree, it's overkill for masters of racing to get miliseconds while downshifting,otherwise a waste of time, and other parts of gear shifting system except clutch(pedal,spring,master and slave cylinder,push-bearing,etc..)
I use it for steep down-shifts for smoother engagement, and to give the synchros a break. With practice it requires no concentration.
Agree. I've been double clutch downshifting since learning to drive from a fellow who drove everything from trucks to tractors to buses and it's made driving any car a hoot! All this effort trying convince people it's a waste of effort and concentration, is a bit over the top imo. Is DC necessary? nope. But in my world it puts the least amount of stress trans and syncros (and whatever else I don't know). BTW , the fellow who taught me all this, 42 years ago, still drives manuals as do I , and neither of us has ever had a trans or clutch wear out, even with some high milers. Each to his own and enjoy, be safe, and above all be courteous out there when whaling on your car and having fun!
inspectorchicken you need to do some research. modern car manual transmissions are junk. if you drive even somewhat spirited. the sycnros fail. for an example go look up a f23 or f35 transmission. they're know for weak syncros.
funny andrew taylor, my 2012 civic si has seen nothing but abuse for 75k miles and its still perfect.
9th: Press the throttle.
Very nice explanation, I've learned this in actual driving on my own (tho I never drive to any track yet) because I just want to eliminate that back drag when your shifting down gears so that you could go more smooth even your just driving in the city, more comfort while driving, comfort for the passenger as well in your car transmission.
(didnt notice that I was doing already 9steps with this method till I watched this)
Even into the 1960s cars there were many cars like my brother's Mini Minor 850 that were sold with no synchro on 1st gear which is how I learnt to double-clutch!
Knowing the technique is extremely useful to get you home or to the mechanic if your gearbox decides to play up on you!
Do you think it's worth mentioning how flywheel weight can affect this? If your flywheel is lightweight aluminum and you are shifting at lower rpms, then on upshifts you may have to blip the throttle.
this video probably has even more views because of people like me that every 6 months on the regular forgets how double clutching works, and rewatches the video
For all the people saying double-clutching is useless in a car with synchronizers, I respectfully disagree, particularly for downshifting.
While downshifting can be a smidge slower since you have the pause in Neutral where you bump the layshaft up to speed, it makes less work for the synchronizers, which have to work hard to speed up the layshaft.
It's usually not all that useful for upshifts, except has anyone driven their manual car in seriously cold weather where it just does. not. want. to. engage. any. gear? Double-clutch all of your shifts (especially between the first three gears), and magically the car will let you get into that next gear until the gearbox warms up and starts to behave again.
Yes, yes, yes, to all that. I had an old Subaru that in cold weather, needed double-clutching until the transmission oil warmed up. Also, I commonly drive a medium-duty truck (about 30,000 pounds GVW) that has a synchronized transmission, but when starting out cold, double clutching saves the day. And I can't tell you how many people I've met over the years who have worn out their first- and second-gear syncros in their cars by doing lots of downshifting into those gears "the standard way," and this could have been completely avoided by double-clutching, even if reserving that method for the more severe downshift situations. As to those who advocate floating the gears, that works, but with synchronized transmissions it's hard to tell if you are really doing it perfectly or not, and if not perfect, synchro wear is actually worse because the synchro clutch is rubbing for a time when the speeds on both sides of the unit are out of synch, but that extra friction accomplishes nothing since it can't cause the input shaft to change speeds in this case.
@@ericl2969 Actually cold weather is still an issue, I have a 2015 Subaru and while switching between the first three gears isn't impossible it is much easier if you double clutch until it warms up.
Is it only applicable in downshifting? So basically it’s just rev matching? Do we really need to go to neutral for that?
Was trying to get a faster acceleration in my old pickup to merge into 60mph traffic on a highway, from a dead stop on a side road. Figured out that if I only release the clutch about halfway when in first when applying the accelerator, then push it all the way in when shifting into second, I can save a fraction of a second compared to releasing the clutch all the way when in first, and also accelerate much faster because the RPM drop isn't as much.
I call this "half-clutching". It makes no sense, probably isn't good for the clutch, but it sounds damn cool. If I tell the kids at work that I can professionally half-clutch in my truck, they're very impressed. They all drive automatic.
Sounds somewhat similar to a technique I've used that I call pulse-clutching while off-roading in an old low-horsepower VW dune buggy. I was trying to climb a very steep hill with deep ruts and boulders and my carb's main jet was clogged at the time, so I was basically feeding the engine unatomized gas from the accel. pump.. Needless to say, I wasn't making enough horsepower to complete the climb, so my technique was to put the clutch in and rev the engine up, pop the clutch to dump the momentum into the wheels, and then to repeat the process over and over until I was at the top of the hill. Really tough on the clutch and drivetrain, but it was certainly better than stalling out and having to back the thing down the hill in reverse.
I think I'm to tired to understand this video. Been driving standard cars and MC since I was 16yrs old for nearly 40 yrs now. I was tought to listen to the engine sound and shift up or down accordingly. Frictioning the clutch is what happens in traffic and chutch breaking correctly to slow down.
Good explanation, would have been great if you showed us double clutching in action. I think you should do video of you doing this technique.
hmm if we're discussing transmission already.
would you do a video on 'dog box transmission'? it's the transmission that was used in the original R32 Godzilla race car. and it seems to be a 'cheap'-ish way to 'upgrade' a transmission if you wanted to go serious racing
The lay shaft or cluster gear here is the culprit. It has to be matched to the speed of the desired gear being selected. This is done either by the synchro brass clutch in a synchro mesh transmission or by double clutching in neutral in a non synchro trans. Double clutching in a race car when approaching a corner saves the brass ring and allows the gear to be selected while braking (heel toe) so the corner can be exited quicker.
On an old 60's 3 speed at a stop light in neutral (clutch out) with non synchro 1st gear, you had to put in the clutch and wait for the cluster gear to stop turning or there was clash. Putting the selector in 2nd first would stop the cluster then you could quickly select first.
Regarding a Corvette that I once owned, this explains why a chattering sound could be heard if the engine were to be shut down while in neutral and with the clutch pedal released - it was the winding down of the lay shaft that was making the sound. On the other hand, it was silent when shutting down the engine while in gear with the clutch pedal pressed (to the floor), which makes sense because the lay shaft wouldn't have been spinning immediately prior to shutdown (well, unless the vehicle was in motion, which it never was).
Wait hold on; so what is the difference between double clutching and "heel and toe" technique?
Heel and toe is when you're braking (perhaps into a corner), apply throttle to rev match the downshift. Only need to press the clutch once (assuming the car has synchros).
+Engineering Explained Oh ok I get now, thanks for explanation and the quick reply :)
+nhilal94 Heel & toe is basically the double-clutching technique explained here, but while braking simultaneously. So you blip the throttle with the heel of your right foot (since the ball of the foot is pressing the brake pedal) instead of tapping it normally as described in this video.
+Engineering Explained technically you don't have to release clutch right ? if braking, 4 to 3, blip gas, release clutch
+Hiroku am i the only one who brakes whit my big toe and blip whit the right side of my foot? i guess i have to big feet
you should show in realistic not only explain on your white board.
so lets cut a car in half and show it?
GloomGaiGar hahaaha
Some of us learn more efficiently this way; with scientific explanation.
Bob Knobgobbler He could do both
Gilang Nurramdhani can he do anything except explain engineering?
If I downshift from 5th to 3rd because i want to overtake someone, can't I just press the clutch once, hold it in, go from 5th to 3rd, rev match, then release the clutch?
I'm kinda new to stick shift.
do you have synchros?
@@bermchasin what are the synchros ?
Haha im not new anymore heel and toe go vroom
In a manual non-synch transmission, when you double clutch, you only press the clutch down part way. The non-synch transmission has something called a "clutch brake" which is engaged when you press the clutch all the way down. The only times you would want to push the clutch all the way down was when stopped with the trans in neutral or sometimes when upshifting on an uphill. The reason for this is because with the clutch engaged, it is turning at engine RPM and you want it to stop turning so you can get it into a gear, since your wheels aren't turning.
I dont understand steps 3 and 4.
Whats the point in matching the speed of the layshaft and the engine, if youre just gonna then match the layshaft's speed to the output shaft right after that? Why dont u just skip neutral by shifting from 3 to 4, rev the engine to match rpm and then release clutch? Cuz then the layshaft and output shaft would be the same speed already, and you just have to match the engine to the rest.
Im a noob here so i dont get it
Double clutching is only needed in an unsynchronized transmission. You see the blue gears on his whiteboard? In a modern car they are all always connected and spinning together and we connect to individual gears with synchronizing rings and the drive shaft sleeve (the black marker on the whiteboard). In a sliding mesh transmission you have to move the blue gears into the teeth individually since they are not connected until you slide them in when you want that gear and having to match the gear speeds perfectly to get them in. Really easy to grind that way which is why we got away from it. So to answer your question, there is no point to matching the gear speeds of the lay shaft, maybe you get marginally less wear on the synchro rings but really I'd say it's negligible.
i always assumed double clutching was a technique used to go faster in a race or just in general. am i correct in now assuming it's just how you change gears in a shotty car?
+tumatauenga Or a car without synchros, many semi trucks require the use of this technique.
Engineering Explained
so it definitely does not make you go fast at all?
+tumatauenga You might be thinking more about heal and toe shifting rather than double clutching, which does help to speed up manual shifts and therefore keep you on the power more effectively.
+tumatauenga No, takes more time because you have to press the clutch twice per shift. You only need it in semi's or older transmissions or if your synchros are worn out. It's never an advantage to have to do this, lol.
Loki Jotunn
i'm just speculating because of fast and furious it's always bothered me cause i have no idea what it is or why you would do it. whats heal toe shifting?
isn't this called rev matching ?
+Erik Angulo ua-cam.com/video/FnXLZg_O1rk/v-deo.html
+Engineering Explained Watched both videos, and still don't understand the difference, could you or someone please explain? Thank you.
+Tomas Prado Rev matching involves pressing the accelerator enough to get the engine RPMs to spin at a rate to match the rotation of the driveshaft. The synchro gears that are part of the gears in the manual transmission box help those gears rotate with the driveshaft as you move the stick into gear. So the driveshaft and the transmission gear are rotating at the same rate. When you release the clutch and the flywheel engages with the transmission gear (through the countershaft), you'll want the engine RPMs to match as closely as possible.
With double clutching, you're lining up the engine with the transmission gears first by releasing the clutch while the transmission is in neutral. Then you want to adjust the RPMs of the engine (and because the clutch is released, the transmission as well) with the driveshaft rotation before moving the stick into the gear you're selecting. This will help the transmission gear and the driveshaft mesh together with less wear. Since the engine RPMs will be rotating at a similar rate when you release the clutch the second time the transfer of power should be smoother.
The essential difference is that rev matching is about getting the engine RPMs to match the driveshaft rotation while double clutching has the added step of using the engine to adjust the transmission gear rotation to ease the meshing with the driveshaft because there are no synchro gears effectively doing it for you.
+Tomas Prado Rev matching is essentially the same thing, except the clutch is disengaged from the engine, and thus all the load of "synchronizing" upon contact is placed on the clutch, not the synchros themselves. When the car is in neutral, your clutch is mashed to the flywheel, and thus all your gears will spin with the engine speed, they just won't be connected to the output shaft. With rev matching, your clutch is away from the flywheel and your gears and spinning at wheel speed, not engine speed. For example; my 2nd gear synchro on my STi is slightly worn out, and at high RPMs tends to grind a bit. When downshifting from 3rd to 2nd, it's easier for me to double clutch and synchronize the gears with the engine than it is for me to rev match and engage the clutch quickly enough to both 1) keep the momentum, and 2) not wear out the clutch and throwout bearing. It's hard to explain without a moving diagram or animation, but hopefully my explanation and Jason's diagram can help.
+Bernie Lee that actually did help thanks
but the double clutch that I learned..."in the racing world"
is when you push in the clutch for a fraction of a second while accelerating to raise the rpm level and then you release the clutch while it is still in gear so the engine will pull at a higher rpm then when you initially engaged the clutch
How old is this guy? He looks young but he's full of grey hairs
Brian Guzman Holden Caulfield!!
He must have had a kid early.
He thinks himself to death
Being an engineer is quite stressful, no doubt in that he's stressed quite a bit
This guy is one of the best UA-camrs . Makes things about as simple to understand as one can.
This is a very good explanation,however, many fail to understand why it is a good thing even with synchronised boxes - if you listen when changing without doubling you can hear the gears spinning up, this is exactly what the synchro hub does, however, if you wish to take the wear off the synchro hub doubling will match the gears and take some of the wear off the hub and it will change quicker and smoother too.
Why do semi-trucks do not have synchros in their transmissions? (i.e. Eaton Fuller 10, 18 spd)
Also, how does hill holding circuit work without waring out the components?
Great videos!
+D. G. Hill hold uses the brakes to hold the vehicle.
What enables the circuit to apply the brakes?
gyroscope
Semi's don't have synchros because they wouldn't last. With the torque a big rig engine puts out and the heavy loads they carry, the synchros would ware out very fast and would have to be replaced very frequently. VERY UNECONOMICAL.
From the ZF brochure from Europe:
■ Thanks to its wide torque range, the Ecosplit
synchromesh transmission gets by with twelve
or sixteen gear steps. A light metal alloy
housing saves unnecessary weight, and the
helical gears allow for quiet running. Shorttravel
and dual cone synchronizers as well
as the Servoshift unit reduce shift forces and
paths. The transmissions of the Ecosplit range,
equipped with an integrated bell housing, are
available in a wide product range for all truck
applications up to 44 tons of total weight.
ZF has already proven that is not true for European trucks.
I once tried to explain the simple process of double-clutching to my ex-girlfriend. Then her head exploded.
I showed my girlfriend how easy it was to learn to double clutch. She was so thankful she gave me head.
Now you told me it works( exploding head) I will try it on my 3 ex wives lol
My crush asked me what double clutching was. Then I gave myself head.
Does shifting multiple gears at once (say 2nd to 4th gear) wear out the synchronizers significantly more?
Well, yes, but if you wait a bit for the rpm of the clutch to drop, it won't be much different. More wear if you do it just as quickly as you would shifting to third.
+Engineering Explained thanks!
+Engineering Explained also i think that depends alot on gear ratios, my vw and audi both have close ratio transmissions and i if I'm really on it I skip 2nd at least and sometimes 4th
Double clutching helps if your trans has worn synchros.
Like mine.
And it sounds cool with a nice exhaust.
Like mine.
Best double clutching movie ever you ask?
That's the original bullett movie.
That's double double clutching if you listen carefully. 😳
Be like that and you are the man..
Thanks. always wondered why you would do it. I learned the day I bought my 06 Hyundai Tiburon. I told the lady selling it that if she wanted me to buy that car that day, she had to teach me standard. She sort of did and I learned the rest. Funnest and scariest two week of stalling and learning of my life. But now I love stick and never want to go back.
I usually double clutch the lower gears and then go to floating around 5th on the 18 speed. If I'm downshifting I usually left foot brake and blip throttle with my right while floating down, letting the engine brake do most the work. It's easy to tell if I get the rev match wrong because the 10k gallons of fuel surges forward in the tanks lol
Isn’t this just down shifting in complicated form?
Its basically turning one motion of downshifting into two, making you push the clutch twice for every downshift.
@@shiekastate Or upshift
Good stuff.
I have never understood why someone would do this? Just feather the gas and keep the revs up. Unless you are driving a split rear end or heavy truck with a non synchro transmission you are just wearing out your clutch.
There's virtually no extra wear on the clutch because there is no load on the input shaft during that extra engagement. You will never wear out your clutch from double-clutching, but on the other hand, downshifting the normal way will eventually wear out the synchros if you keep your car long enough, especially resulting from high-rev downshifts. I've seen quite a few cars with totally blown synchros on 1st and 2nd gears. It's not rare at all, and double-clutching to minimize that wear during the most wear-inducing kinds of downshifts isn't such a bad idea.
@@ericl2969 Hello, I just bought a 2012 WRX with 84,000 miles on it and noticed some grinding going from 1st to 2nd. Figured it had to do something with the synchro, but not quite sure exactly. It works fine when double clutching and shifting slower, however. The other gears have no problem shifting.
@@kylewininger6824 definitely syncros, and you should let the throttle burn out when upshifting for smooth shift, also double clutch when downshifting to minimize wear.
I do this every day 15 gears up 15 down #thankatrucker
Yep, I learned to drive a truck before I ever drove a manual transmission car. I thought this was the only way to downshift lol.
Once your rolling never use the clutch, just accelerator pedal when gearing down.
@@martinwarne7183 first thing I learned when driving a semi. Might be the only thing :)
Used to drive my old Saturn like this... Much harder lol
@@martinwarne7183 so act like the clutch is gone and find the slip point? I'm about to go to school for trucking but hoping to learn more before I go.
@@Matthew-ev4cv as if the clutch is inoperable. When gearing up, 1st to 2nd gear you have to let the engine speed slow down a little, to allow the gears in the transmission to match speeds on the main shaft and the layshaft in order for them to mesh. Conversely, when gearing down the engine speed has to be raised to match the gear speeds so that they can mesh. This is where the engine tach is important as it does help a lot. Most transmissions on trucks have a 500rpm difference between gears and if it has a splitter it will be 250rpm. That's the basic principal, practice is the key, don't get rammy with it, after a while you can feel what is going in the transmission. Hope this helps, if you have any questions get back to me. Best wishes and good luck. Martin.
I triple clutch and it actually regenerates my clutch and synchro.
Nice. My buddy’s Old Man had some sporty Escort and explained double-clutching when we’d rip down our town roads. Great illustration here.
What is a "modern" car defined in this video?
5, 10, 50 years?
How would I know if the car has syncos?
Did this going down an A road at 60 went from 6th gear to 3rd, that engine noise was beautiful and the speed was sublime
Rip your valves
@@imthedarknight-8755 haha my mothers valves I was a learner at the time, now if I double clutch its only from 5th to 4th. So guess I learned my lesson
I still don't get why you'd need to do this. Yes I syncro or not, getting the gears up to speed is a reason. But why would one want to do this?
To shift gears.
+Rohan Thatté It's about how it was harder to shift gears, harder to drive, before the synchronized transmission was invented.
+Rainer67059 I understand. And roughly what era are we talking about? I'm 29 and fascinated with all things with engines, only in the "referenced" movie, did I first hear it. Was this required for all cars/trucks before a certain year?
+Rainer67059 I understand. And roughly what era are we talking about? I'm 29 and fascinated with all things with engines, only in the "referenced" movie, did I first hear it. Was this required for all cars/trucks before a certain year?
+Rohan Thatté
In America the end of this era began in 1936. The car industry introduced this new transmission in 1936. It ended I think, exactly then. But trucks and busses may have had non-sync transmissions for longer.
The 1934 La Traction Avant by Citroen was the first car to have a fully synchronized transmission. Although this technology originated in Europe, its success was faster in America. My father told me to have to apply the technique on his early cars. He started motoring with a Vespa in the 1950s.
This pretty much confirms the 4th gear synchro in my Subaru Legacy is dead. Almost always grinds/crunches when going into 4th gear, up or down. Recently I experimented with double clutching up shifts and down shifts and it almost never crunches when doing it this way. 4th is the only gear with the problem. Great video.
Is this not just rev matching? If not then please tell me.
The Deuce-And-A-Half I drove in the army needed to be double clutched.
The Cat Ate My Shoe no it didn't, not a single transmission in the world "requires" double clutching. You just don't know how to float.
Lmao when I first started driving, I just liked double clutching more than the normal clothing, because it was more comfortable for me and smoother
that's where I am right now lol. I didn't even realize it wasn't needed for my car but not it's muscle memory
Americans that explains Manual Cars what year is this ?
My old man has been driving an old truck like that for over 10 years. To this day, with multiple operators, he is the only one that can down shift without grinding. Old skool gear box with no synchro and you can listen to him rev the engine to get everything turning at the right speed.
Question regarding trucks -I was instructed NOT to double clutch when driving a old Volvo truck, why is that? I was double clutching which seemed to help with its slightly difficult gearbox. Thanks for excellent brisk tutorials, giving reasons why.
What? I thought this was just regular downshifting, your telling me I’ve been double clutching the whole time and I didn’t even know what it was?!
Yep. :D
@Engineering explained How long did you go to school for all of this man? You know ALOT of stuff about cars.
I knew what double clutching is untill I watched this video.
I learned to drive in a 1949 Ford 1 ton truck. It was necessary to double clutch because the transmission did not have any synchros because that's how it was built. Also, 1st gear was meant for very heavy loads and was called the "Compound gear". Without a load in the truck 2nd gear was used to get going.
I am a big rig driver and I use this method all the time particularly with down shifting. Timing is everything! I have witnessed new drivers trying this and will grind an Eaton Fuller ten speed transmission to powder if they don't get it right.
Fast and Furious fans always talking about double clutching and more than half of them don't even know what that is...
I'm so sick of FaF fanboys, they are everywhere..
"Hey Toretto"
"blip" the throttle? you mean "tap" right?
+Acclamator55 yes!
details that are crucial. lol rlly dude
Let's play, "Spot the Car Noob!" Ready?
Let's play "Spot the Troll", ready?
Found you, what do I win?
When my dad taught me to drive he taught me how to change gears in a standard transmission. I learned how to double clutch then later I learned how to float the gears which is a way to shift without using the clutch at all. After that I only had to use the clutch when I had to stop, start from a stop, or reverse. Haven’t driven a standard transmission for years but I bet I could still float the gears. It might be a little sloppy for a bit but who knows until I get a chance to try. In this day and age finding a standard transmission would be harder than floating gears.
Does my opel corsa c have a syncro?
Granny shiftin not double cluchin like you should
eurosonly yes I was looking in the comments for a fast and furious reference lol
Dude I almost had you
C'mon, almost all cars that have less than 30 years old have a syncro so there is no need for double clutching.
The only reason in the first place was for the delay. Nothing else.
J Silk,the reason for double clutching is to get it in gear.I have to double clutch in my car when down shifting to first because it is an unsynchronized gear.
Nope, you're wrong dude. I've driven Model T's; MGs and Austin's from the 60s.. It's all about the delay for the gears and clutch plate to sync ... nothing more. you could go for a drive right now, put you foot on the clutch and hold it there as you count to two Mississippi and then switch gears - no grinding gears, no problems at all.
Stairway to heaven Bohemian rhapsody you should never downshift to first
Hmm I drive a 11’ jumbo transit van and I definitely need to double clutch between gears 1-3. A lot smoother transition when I do so, syncros are probably a bit worn after years of carrying a lot of weight. Informative video none the less
Bro, seriously...? If you are a real driver, you can change the gears in a fraction of a second. That means the engine doesn't even have time to breathe, much less come down in RPM. So the double clutching thing sort of feels like unnecessary time waste and a delicate conscious effort while changing gear every time. Because I almost always change gears sub-consciously within half a second. Double clutching would take years to change a gear. LOL
You actually rev match because lower gears are shorter therefore spin faster
Wrong. You need to get the RPMs up based on the gear ratio. It's not just about shifting speed.
IF, and its a big IF, you are really good you only have to use the clutch to initially engage first gear when starting from a stop and do not have to disengage it till you stop again. The problem is this can cause damage if you are not really good at matching the engine speed to the ground speed for the gear you want. With synchronizers you can gently feel when to engage the gears. I have driven home a couple times with a broken clutch linkage. shut engine off to stop after slipping trans out of gear as you coast down. with engine stopped put trans in first. use starter to get going and just shift carefully. I never broke or ground the gears etc. There are things you can do sometimes that work if you think about it.
This is more related with synchronizers: In Sweden, rev matching is not taught at driving schools but merely something you have to learn on your own. I don't do it, but I'm thinking about learning it. For me, there are two alternatives to get the downshifting smooth then; Assume I need two change down to 2nd gear before a curve coming in around 32 km/h, I hit the brake gently, change down to 2nd and then release clutch to biting point and keep it very gently there. You'll see the engine starts to brake for you, and when it's done; foot is off the clutch and the speed should be about 18-24 km/h. Or I use the brake more "harder" and shift down when the speed is about right. Both cases are completed before turning. The car is always smooth. But I assume I'll have less wear if I rev match?
grey hairs? I thought he was 17
I Almost Had You
granny shiftin, not double clutchen like you should..
the expression i """double DE CLUTCHING"""
It's double de-clutching in UK and double clutching in USA.
the action of pushing in the clutch actually means the clutch is disengaged which is why having the clutch pressed down is essentially having the car in neutral I think. The action of taking your foot off the clutch when in gear means the clutch is engaged to actually drive it so that it's not in "neutral" anymore.
Had to do it in my second vehicle, 41 military 1/2 ton closed cab pickup. Straight cut gears with granny low 4 speed. Took a bit to learn the idea but once I had it down it was very easy to shift up or down. Sometimes I could even shift up without using the clutch going up on a good day. Very tough transmissions in those old Dodges, only saw one with a broken tooth and it still worked, just clanked when it hit the missing tooth.
I learnt about double declutching when I learnt to drive (and non synchromesh gearboxes were still relatively common in older trucks), but was never actually taught it.
I used it on one of the works vans when the synchromesh failed for 2nd gear, and despite my being the youngest driver there, was the only one not to crunch 2nd in that van.