There’s no need to double clutch when you have synchros this is for a lot older cars and trucks and buses not newer cars that you can rev match and not have a problem
It is but fast and furious is full of rubbish like this and 'blowing the welds on the intake' for example but it does make it really funny to watch. Donut made a great video about it
@@tadassmolskas3014 you can blow the welds of an aftermarket intake from more boost that it can handle. But they dont apply it correctly. They can say their car is knocking and be talking about a loose bumper tapping the car.
@@darthbolloful wrong, if your engine blows before your intake you got bigger problems. Plenty of UA-camrs intakes have busted their custom intakes. That guy flat 6 swapping his WRX is one example.
@Darthbolloful I've seen someone try and run boost through a polymer intake, i was glad that the hood was closed, or I would have a lot more plastic than I should.
Just a fun fact for everyone, semi trucks don't have synchros so you're supposed to double clutch but most people don't cause you can "float " instead ie , bump the throttle and pull the stick out of gear, then rev match or just go strait into the gear if your rpms are right.
Yes, and if you’ve been driving semi trucks (in the US) long enough, you’ll find yourself climbing into the seat of the 1997 Ford Ranger you refuse to spend your hard earned trucking money to replace, and you’re floating the stick in it, too. Because once you’ve learned to float a non-synchronized transmission, you can probably float an automatic…
@@L0VTX_H8CA I had an old Toyota pick up that would leak brake fluid out of the clutch master cylinder so I would float it home until I could top it off. The principal is the same.
Hard? It's impossible. On motorcycles the gear is linear. You literally have to go through all gears to go from neutral to 6th and vice versa. You can't go to 6th from neutral with double clutching.
Almost a great description. The ultimate goal is to match the speed of the engine to the speed the trans will need to be in the gear you are heading to. It’s mainly useful for down shifting. When shifting from say 3rd to 4th the trans and engine will both drop speed between gears which will often match anyway, but when you are going from say 4th to 3rd you will your engine and trans will need to be spin faster to match. If you can get the revs up to that higher speed perfectly you don’t even need to press the clutch - it will drop right in. That’s the goal. Match the revs.
Very good description. Modern cars with synchromesh don't require double clutching but it's better and less wear for your gear box provided it's done properly and the revs are actually matched. If you're double clutching but not getting the revs right (revving on upshift etc), you could be actually giving the synchromesh more work to do, so either get it right, or don't do it at all I reckon!
They may have been invented then but I would assume most cars didn’t get them until the early 30s at least. By the mid to late 30s most cars had synchros. Late 20s cars did not.
@@pierce_arrow1798 Well yeah definitely. Im pretty sure cars without synchros weren’t uncommon until the 70s. Just said that for the sake of the joke lol
My 1939 3 speed gear box I put into my flathead hotrod only had synchro mesh 2nd and 3rd. Non syncro 1st. The same era truck 4 speeds were 4 speeds with no synchro
For downshift you want to blip the throttle while you engage the clutch in neutral to bring the revs of the engine and the transmission shaft in the right range. For upshifts you need no throttle because the shaft and engine needs to spin slower and it by default gets slower by inner friction.
I still revmatch on gear 5/6, I shift slowly going into 5th and 6th cuz im still wary of misshifting, and by the time I've got into gear im at idle when it should be at around 1500, so to make it more smooth I give a little upshift blip. and whenever i shift into 2nd I have to wait extra long to let the revs drop otherwise the car doesn't like me dropping the clutch with too many revs
Be gentle and smooth when putting your car in gear so you don't wear out your synchros and you can pretty much forget all about double clutching. Irrelevant in a modern transmission. For all those who are saying that it will reduce synchro wear, probably true, however, you have now used your clutch significantly more which may prematurely wear it instead (I'm talking the bearing and spring plate, not the friction material). Lets not overcomplicate this. Be gentle with your transmission. Rev match as smoothly as you can. Don't ride the clutch. Don't dump the clutch unless its an emergency (impending rear-ending, etc). Change gears as little as possible (manage following distance, time traffic signals, anticipate gearing, etc).
Dump the clutch, do wheelspins, rev the engine to the moon all you want it won't do nothing to your car. If you take care of it and ride it within its limits the.you're good
You should look into double clutching on a semi truck. The cool thing about semi trucks is that you don't actually need to use the clutch once the truck is already rolling. Because it's a non synchromesh transmission at the right rpm it automatically aligns itself and you could just slide from one gear to the other just using the throttle even on downshifting.
you dont need it on a syncronized transmission either. if the gears are moving st the same speed they will mesh. do it all the time when im casually driving.
Up shift is just waiting for gears to match. Downshift just pop in neutral, rev match and slam it in gear. Works smooth in you have your ratios down but pretty pointless in a regular car
Great knowledge, my 2005 tacoma 5th gear has syncros has been iffy for 7 years, I usually just skip from 4-6. But 6-5 is fine. I’ll double clutch from 4-5 next time I drive.
@@pdxmateo9022I got a Ford zf5 with the second gear synchro out and all you gotta do is know your rpms I can shift straight from 1st to 2nd no problem and 3rd as well but normally I start in second anyway
rev matching isn't double clutching, it's just blipping the throttle right before you release the clutch on your downshift, serves the same effect on modern syncromesh transmissions. Also increasingly irrelevant as a lot of manual transmission cars these days have auto rev matching.
So there’s actually a small mistake here, double clutching on downshift does nothing if you rev match while clutch in, this is actually one of the biggest advantages of the double clutch, you need to rev match while clutch out and in neutral, then you need to clutch back in and shift quickly otherwise the double clutch is completely useless because your desynchronizing the gearbox, which was the whole point of the double clutch.
Finally someone actually knows what they’re talking about The only thing the dude is doing in this video is adding more wear on his clutch and synchros because he let the revs drop to idle. 🤣 No point double clutching if you don’t blimp the throttle in neutral with the clutch out.
That's the point of the video. These days it's pointless.* They'll outlive the gearing these days. Make sure you're rev matching though. That's not just for longevity but for performance and even saftey. *Unless you're driving with an old transmission design.
You blipped after you put the car into the third on the downshift which defeats the purpose of double clutching. The point is to match the revs with the car in neutral and the clutch out so that it goes into gear easier. Even for the upshift, you let the revs fall too much which would work the synchros more. If you want to learn to do it correctly try to do it without the clutch. That will make you match revs correctly cause you can't just rely on syncros
daily drove a 64 chevelle for years and i got to a point besides sitting at a stop i never touched the clutch, I got to a point where i could rev match perfectly every single time.
Just shift like normal bit keep the throttle cracked so the engine is close to your target RPM for the next gear. I use this allot if I am wanting to keep the turbo spooled between gears on my 1.9TID as I can keep around 7-10PSI of boost going into the next gear instead of waiting for the turbo to come back up from 0PSI.
Those gearboxes love to be powershifted, last forever if you are under 400hp. Funny how you can bang all gears and they enter smoothly, try to put it in reverse while completly stopped and you feel it fighting you
This is true. First company out of trucking school has strictly manual trucks all with 1M+ miles. Never even drove a single manual car before this. Now 10 months later and an ungodly amount of grinding it comes naturally😅
@@reyesI165 lol I know the feeling, You just shift and hope you’ll end up in the right gear. But yeah in terms of manuals, it’s easier to learn to drive a semi if you haven’t driven a manual car before. I unfortunately learned stick on a Subaru so it was hard to be gentle on that poor freightliner
Double clutch on a semi? Only in CDL school and on your test, once your on the road you float gears or curse the "genius" that invented automated/automatic transmissions. Or you grind like hell and get stuffed into the one auto on a stick fleet (odds are, its transmission went out of production a decade ago so have fun with a transmission thats not quite all there in the computer)
But what you forgot to mention is you need to increase the rpm in between the shift to match the input shaft speed to the next gear speed. This is how you shift a big truck transmission. But what is easier is to just float the shift without touching the clutch.
It's not the cut off the gears that matter. Straight cut is just for strength but are noisy that's why cars have helicoil cut. All gears are always in mesh, but are not in dog. Cars have a synchro mesh in the dogs to speed up or slow down the gears to match the input and output Shaft.
in my 12 years truck driving i only ever used the clutch taking off lol. float em up and down, impress the DOT officer that rides with you when you get your CDL.
Double clitching is still a valid technique when dropping down from a high gear to a super low one, as it will reduce the wear you put on your synchros :)
On the upshifts, it still makes sense. The transmission has lower frictional losses, thus it takes it longer time to "slow down". Engine has higher frictional losses, slows down faster. So by releasing a clutch in neutral, you are essentialy slowing down the transmission to the correct (slower) speed. This could be also achieved by upshifting slower, or letting synchros do the work. On the other hand, when downshifting, the transmission will not speed up automatically (as opposed to slowing down on upshifts), so on downshifts, you release the clutch in neutral (while also revmatching) to get the transmission up to speed. This is far more "important" if you will. So double clutching on upshifts is not nearly as important, but still makes sense, because you are not using the synchros to slow it down, but rather a clutch with the engine.
Yeah don’t bother, it’s for driving a race car smooth so it last a long time but synchros are there for a reason. You don’t need to heel toe either but that one is actually a useful skill if the pedals are the right distance for your shoes
On old sliding mesh tractors (I still use) it helps to double clutch, they can be very hard to put in gear on fhe move, but when it comes to disassembly of the gearbox, it's very simple relative to new gearboxes. 3 gears on the main shaft, 3 on the lay + reverse idler, high low box on an planetary 4:1 reduction, that's about it.
Tha k you for mentioning that it's not necessary in modern cars. Half the fools out there trying to double clutch to be cool and just adding more wear and tear on their shit. That being said, it's pretty cool seeing an old schooler do it super fast and proper.
@@QuincyStick Mines got a bad synchro on 5th and grinds. Double clutching it smooths it out everytime lmao. When i drives others cars, i double clutch 5th out of instinct.
@@GewelReal not all synchros are made the same. Some are made very poorly and give out fairly early. Also many people like to drive their cars for hundreds of thousands of miles, and synchros will wear out eventually on their own even with good driving, double clutching helps extend their life even further.
Unless your driving a semi double clutching is a waste of time. If you want to be nice to your transmission and make it last a long time slow your shifts down so your syncros arent working so hard to match gear speeds
@@Moto848 imma stop you right there. Im a driver too. I know lol. i float my 10 speed 04 t800. Im just trying to point out that the only time you would double clutch is in an unsynchronized trans like a semis.
When I prepared for my Class A CDL you have to double clutch for the test to show you know how to modulate the clutch. After I got my license I never double clutched again. Just clutch for start n stops then float gears which is way more fun.
Apples to oranges. Class A trucks are all unsynchronized AFAIK, where all class C vehicles are going to be synchronized transmissions. That being said any class A driver that's been on the road more than a week is going to float gears aside from maybe 1st to 2nd.
Some modern era cars didn't have syncros in 1st or their syncros are worn out. Double clutching has its place for down shifts, but not necessary in most situations. Syncros are a wear item like brake pads, but they're inside the transmission. Keep that in mind...The more smoothly you shift and the more you double clutch to spin up that gear instead of letting the syncros do it, the slower they will wear.
But so is a clutch, and the clutch wears much faster. I've changed plenty of clutches and slave cylinders which required dropping the trans, but never synchros, so I wouldn't worry about those too much. I'd say let the synchros do the job they were designed to do.
I used to DoubleClutch my Datsun i had back in the day. And from my experience is that every time i go into the new gear doing a DC it feels almost like my car had that little extra power. Now i maybe wrong but that was a lot of fun.😢 miss my Datsun.
This can still speed up your downshifts if you rev match perfectly. The goal is essentially to get your trans input shaft and clutch rotating at the exact speed they will be when the input shaft is locked to the output shaft. You have to do this on every downshift when youre floating gears otherwise itll grind and not engage at all. The synchros do this for you through friction, but a quick double clutch downshift is faster and much more satisfying. Double clutching on an upshift is counterproductive as ot increases the difference in speed between the input and output shafts making the synchros work even harder.
@@yorkshire_tea_innit8097 Straight, helical, wooden pegs doesnt make a difference. An upshift requires the input shaft speed to slow down. This happens naturally when the clutch is pushed in so double clutching and allowing the engine to slow the input shaft down is redundant and a waste of time. The only time an upshift requires a double clutch is if you took too long to shift and the input shaft speed is now too slow. Downshifting requires the opposite - to increase the input shaft speed. The only way to do this (besides syncros), is to rev the engine with the clutch engaged and transmission in neutral - double clutching.
Jesus man it’s about time someone just explains it instead of going off on an extremely confusing 30 minute rant about how and why but never really explaining it right. You just get straight to the point short and simple. You have no idea how many videos I seen where they never explain it or it’s extremely confusing
to be fair he didn't really explain it here. I'd advise finding an in depth video actually explaining why and what it does and how it is still helpful even with modern transmissions.
Synchronized transmissions are fun My old s10 was great to let off throttle. No clutch, and just snap the shifter into the next gear Ull grind a few times till u get hang of it. Then ull be powershifting. Almost instant gear changes
in Russian cars sometimes the car won't go into gear unless you double-shift. The gearboxes does have syncros but still you need to double-shift every now and then. Actually I had to do it yesterday on my driving test :)
@@abdullahlibzo6914 wow that's crazy to hear newer cars needing synchros 😮. My oldest truck is an 85 and doesn't require double clutching. I did drive a 1931 Pontiac sedan with a three speed , that of course needed it 😂.
there are situations too do this, a worn transmission would prefer you treat it this way similarly too how old automatics prefer you rev with the shifting too reduce wear and increase efficiency
If upshifting, just push the lever into the next gear up but not fully, applying gentle pressure. As engine RPM drop, the lever will happily pop into its spot, meaning the engine’s RPM has dropped enough to match the desired gear’s ratio, is spinning at just the right speed for the dogs to actually line up and be “synchronized” to the next gear, allowing the shift collar to slide along the main shaft, siding itself into the female end of the gear combo you’re selecting. You never actually “shift gears”, theyre in constant mesh and are bevel cut for quiet operation. What you shift is a 2-directional (back and forth) collar, with square-cut gears (dogs) with a brass or other soft metal synchro clutch on the outer circumference that fits into the gear combo’s friction ring, that slows down via friction (upshifting) or speeds up (downshifting) the engine’s input shaft speeds determined by the clutch engagement.
Actually there's still a benefit to double clutching a synchronized manual, as it reduces wear and tear on the syncros. This applies more to down-shifting, especially big down-shifts, like 5th to 2nd @55MPH, where the input cluster needs to be spun WAY up from say, 1800RPM up to 5500RPM. In the same way that rev matching reduces wear on the clutch, rev matching combined with double clutching reduces wear and tear on both the clutch and syncros.
Yeah but in sport and wrc cars they doesnt have synchos in geabox,because of that they have sequential shifters... and if you have dont have sequential and dont double shifting you beting the shit out of your gearbox...
Non syncroed transmissions had a clutch brake, when you pressed the clutch pedal the clutch disk would stop spinning so the gears didn't grind. Double clutching ensured everything stopped completely. Modern syncros only stop the gears involved in the gear change from spinning instead of the entire gear cluster and disk.
Double clutching in this reference is referring to the way a rally car driver does it. Where you push the clutch and high rev the engine while shifting
Actually bro, it still has it's uses with engine braking and hard stops or helping you NOT unset the balance of the car when slowing down for corner entry- you can effectively down shift at higher revs and not have to worry as much about compression lock ups
As a trucker we're taught to double clutch and in most schools you will fail your test if you don't but once you have your license you can float your gears
He's absolutely right. I've driven non synchro trucks. However, we used to double clutch and rev up the engine when downshifting. Made a significant difference. Maybe still worth it in synchro transmissions if you are a huge racer :)
Double clutching is to avoid using the synchronizers to bring the engine up or down to speed while shifting gears. Double clutching down in the lower gears, especially from 3rd to 2nd, or even from 2nd to 1st, is a great way to minimize synchronizer wear. Also makes you sound cool. :p
Yeah, when I saw F&F back in high school, I was confused why someone would double clutch in a drag race. I think the writers meant when you press the clutch in while in low RPMs to get the flywheel spinning and drop it to get a little burst in speed. When you accidentally put it in too high of a gear it’s a nice little trick to get going.
Double clutch downshifting is only effective if you rev match while in neutral instead of rev matching while on the clutch. Otherwise you’re not actually synchronizing the clutch for the next gear
My favorite part is they said that in the movie but the actors couldn't actually double clutch convincingly so in every scene I watched they all just shifted normally :P There would be some logic to double clutching when rapidly accelerating or decelerating while street racing since the synchros would wear out faster and the racers wouldn't be rebuilding their transmission after every race (or every few) like professional race teams often do.
Nice job of explaining. For me the reason of why would be for proper training clutch use giving the operator a feeling and understanding of how their trans operates after getting so familiar with it one might be able to float gears. Floating is a technique utilized by big rig drivers of down or up shifting without using the clutch, once this can be mastered it could be applied to a racing application which would be beneficial when left foot breaking (really common use for rally or touge runs). I think covering of floating would be good for you to cover.
There sre still valid uses for double clutching in a Synchromesh transmission. For example, when the transmission is cold, shifting to 2nd can be super notchy or outright grind. DCing will make the shift smooth guaranteed. Second, if you brake heavily and shift from a really high gear to a low gear, skipping many gears, the synchro is also gonna struggle shifting. DCing will, again, shift smoothly.
I like that it has cuts, probably paying attention to traffic and continuing the conversation once he has a second, or maybe it's just shorts and he cut out rambling. 😂
Still reduces wear on synchros *and* smoother shift felt through the car. Great when you have passengers, or have to skip 2-3 gears. There's than just the synchro involved, and more disconnected than this gives credit for. I personally didn't like the the idea increased clutch wear, so I'd recommend clutchless deshifting for people that care for that
Adding on to what is said here... Some gboxes can't be quick shifted because it will either not select or start grinding so double clutching stops you having to wait for the speed of the gears to match hence why some old people sound like it takes them years to change gears!
While I understand what he's talking about here, I don't think that's what the character meant in the movie. I think what the character meant by "double clutching" was, in higher gears (3-6) after the initial release into that gear (when its just the motor pulling and bogs a bit), you pop the clutch in and go to redline and pop it out again in that same gear. While this can gain you a little time/speed, it is very hard on all of the components.
Rev match in neutral with clutch engaged. I always do it, even in sports cars, when going into low gears or downshifting down 2 gears at once. Saves the synchros
It is actually possible to drive a manual transmission without using the clutch at all. I have done it when the clutch mechanism has failed. Shift into neutral to stop, shut the engine off, select first and start the engine to get going. Lift off the gas as you pull through neutral into second. Lift off the gas for each up shift and for downshifting blip the throttle as you pull it through neutral into the lower gear. You can feel when you do it correctly and you can definitely hear when you messed up.
It's also why semi truck transmissions say to double clutch, but outside of doing your driving test I've never seen any driver actually double clutch a newer Eaton Fuller. We us the clutch when at a stop to get the truck moving, or when going in reverse, any other time we are floating gears.
Exactly bro, finally someone who knows what they are talking about.
There’s no need to double clutch when you have synchros this is for a lot older cars and trucks and buses not newer cars that you can rev match and not have a problem
@@caidentulip455 There is a use even with modern transmissions. If your synchros are worn, this helps.
He hasn't a clue says one thing but does something else !
But still always a safer practice reducing wear and. Tear
@@caidentulip455 thank you…. Saved me a long time lmfao
i literally uttered "but why" and he immediately said "the better question is why". Man's one step ahead
😂
ikr me too
Me too 😂
Hahaha lol
Bro is Aizen
Granny shifting feels like a more appropriate term for this double clutch method lmaoooo
It is but fast and furious is full of rubbish like this and 'blowing the welds on the intake' for example but it does make it really funny to watch. Donut made a great video about it
@@tadassmolskas3014 you can blow the welds of an aftermarket intake from more boost that it can handle. But they dont apply it correctly. They can say their car is knocking and be talking about a loose bumper tapping the car.
Modern cars don't really need all this stuff tbh
@@darthbolloful wrong, if your engine blows before your intake you got bigger problems. Plenty of UA-camrs intakes have busted their custom intakes. That guy flat 6 swapping his WRX is one example.
@Darthbolloful I've seen someone try and run boost through a polymer intake, i was glad that the hood was closed, or I would have a lot more plastic than I should.
Just a fun fact for everyone, semi trucks don't have synchros so you're supposed to double clutch but most people don't cause you can "float " instead ie , bump the throttle and pull the stick out of gear, then rev match or just go strait into the gear if your rpms are right.
I'm glad someone else knows this. Also because of the amount of travel trucks do we float because it saves the clutch.
American trucks*.
We who drive European trucks habe symchros and don't have to care. And most of the time, we drive automatic anyway.
@Skelterbane69 thats pretty neat
Yes, and if you’ve been driving semi trucks (in the US) long enough, you’ll find yourself climbing into the seat of the 1997 Ford Ranger you refuse to spend your hard earned trucking money to replace, and you’re floating the stick in it, too. Because once you’ve learned to float a non-synchronized transmission, you can probably float an automatic…
@@L0VTX_H8CA I had an old Toyota pick up that would leak brake fluid out of the clutch master cylinder so I would float it home until I could top it off. The principal is the same.
It’s pretty hard to double clutch on a motorcycle. Going 110 than shifting all the way to neutral than 6th gear
💀💀
Lmao! “Why are your left calf muscles so much bigger then your right?” “I double clutch.”
Hard? It's impossible. On motorcycles the gear is linear. You literally have to go through all gears to go from neutral to 6th and vice versa. You can't go to 6th from neutral with double clutching.
Theres literally no need to double clutch on motorcycle. Rev matching is only needed for down-shifting, up shifts are smooth af (on good bikes).
@@anishdebnath3142 thats the joke
Almost a great description. The ultimate goal is to match the speed of the engine to the speed the trans will need to be in the gear you are heading to. It’s mainly useful for down shifting. When shifting from say 3rd to 4th the trans and engine will both drop speed between gears which will often match anyway, but when you are going from say 4th to 3rd you will your engine and trans will need to be spin faster to match. If you can get the revs up to that higher speed perfectly you don’t even need to press the clutch - it will drop right in. That’s the goal. Match the revs.
Very good description. Modern cars with synchromesh don't require double clutching but it's better and less wear for your gear box provided it's done properly and the revs are actually matched. If you're double clutching but not getting the revs right (revving on upshift etc), you could be actually giving the synchromesh more work to do, so either get it right, or don't do it at all I reckon!
Synchros: Invented in 1919
People in 1918:
They may have been invented then but I would assume most cars didn’t get them until the early 30s at least. By the mid to late 30s most cars had synchros. Late 20s cars did not.
@@pierce_arrow1798
Well yeah definitely. Im pretty sure cars without synchros weren’t uncommon until the 70s. Just said that for the sake of the joke lol
My 1939 3 speed gear box I put into my flathead hotrod only had synchro mesh 2nd and 3rd. Non syncro 1st. The same era truck 4 speeds were 4 speeds with no synchro
@@hughstewart547
Yeah, again with my previous comment i’m pretty sure that gearboxes without synchros on every gear only became uncommon in the 70s
Engineers in 1990s: still not putting synchros for first or reverse
Careful, you might blow the welds on your intake and your floorpan will fall out.
You'll be lucky if you didn't fry the rings
Then me and the mad scientist have to rip the block apart
And damage the exhaust seals, then all the water will leak out
I somehow decapitated a giraffe by following these instructions pls help
Forced induction can blow the welds of an intake.
For downshift you want to blip the throttle while you engage the clutch in neutral to bring the revs of the engine and the transmission shaft in the right range.
For upshifts you need no throttle because the shaft and engine needs to spin slower and it by default gets slower by inner friction.
Pontosan barátom!
Glad someone pointed this out. Double clutching on a downshift doesn’t do anything if you don’t rev match in neutral.
I still revmatch on gear 5/6, I shift slowly going into 5th and 6th cuz im still wary of misshifting, and by the time I've got into gear im at idle when it should be at around 1500, so to make it more smooth I give a little upshift blip. and whenever i shift into 2nd I have to wait extra long to let the revs drop otherwise the car doesn't like me dropping the clutch with too many revs
Be gentle and smooth when putting your car in gear so you don't wear out your synchros and you can pretty much forget all about double clutching. Irrelevant in a modern transmission. For all those who are saying that it will reduce synchro wear, probably true, however, you have now used your clutch significantly more which may prematurely wear it instead (I'm talking the bearing and spring plate, not the friction material). Lets not overcomplicate this. Be gentle with your transmission. Rev match as smoothly as you can. Don't ride the clutch. Don't dump the clutch unless its an emergency (impending rear-ending, etc). Change gears as little as possible (manage following distance, time traffic signals, anticipate gearing, etc).
Dump the clutch, do wheelspins, rev the engine to the moon all you want it won't do nothing to your car. If you take care of it and ride it within its limits the.you're good
So, the epitomy of "mechanical simpathy". ;-)
@@str8xrippin dude, I love working on my car... but not ALL THE TIME
I have to double clutch to put my economy Toyota Agya in reverse. I'm in Indonesia btw.
What is dumping the clutch?
You should look into double clutching on a semi truck. The cool thing about semi trucks is that you don't actually need to use the clutch once the truck is already rolling. Because it's a non synchromesh transmission at the right rpm it automatically aligns itself and you could just slide from one gear to the other just using the throttle even on downshifting.
you dont need it on a syncronized transmission either. if the gears are moving st the same speed they will mesh. do it all the time when im casually driving.
@@thesuperjank6109 I've never been able to do that with a car before. Neato.
Up shift is just waiting for gears to match. Downshift just pop in neutral, rev match and slam it in gear. Works smooth in you have your ratios down but pretty pointless in a regular car
A good way to shift when your synchros are fucked 😂
As an owner of an 82 Toyota pickup with no synchros left I can attest to this, it's actually very smooth to drive once you learn the technique
yeah my brothers e39 m5 needs a new trans cause his slave cylinder and selector rod got jammed frying his synchros
Helps you with crashboxing it home when your clutch is fucked too had to do that plenty of times lol snapped clutch cable life is fun 😂
Great knowledge, my 2005 tacoma 5th gear has syncros has been iffy for 7 years, I usually just skip from 4-6. But 6-5 is fine. I’ll double clutch from 4-5 next time I drive.
@@pdxmateo9022I got a Ford zf5 with the second gear synchro out and all you gotta do is know your rpms I can shift straight from 1st to 2nd no problem and 3rd as well but normally I start in second anyway
You should also mention double clutching is used when downshifting while decelerating hard and you want to stay in gear for the upcoming acceleration.
rev matching isn't double clutching, it's just blipping the throttle right before you release the clutch on your downshift, serves the same effect on modern syncromesh transmissions. Also increasingly irrelevant as a lot of manual transmission cars these days have auto rev matching.
So there’s actually a small mistake here, double clutching on downshift does nothing if you rev match while clutch in, this is actually one of the biggest advantages of the double clutch, you need to rev match while clutch out and in neutral, then you need to clutch back in and shift quickly otherwise the double clutch is completely useless because your desynchronizing the gearbox, which was the whole point of the double clutch.
Thats what I thought 😂😂
Correct, I’m glad someone else caught it
@@J8Airfacts, heard that right away
Finally someone actually knows what they’re talking about
The only thing the dude is doing in this video is adding more wear on his clutch and synchros because he let the revs drop to idle. 🤣
No point double clutching if you don’t blimp the throttle in neutral with the clutch out.
Oh thank God somebody else said it!
if your gearbox has synchros (practically any modern manual does) doubleclutching is completely pointless
Imma let my synchros take care of it
That's the point of the video. These days it's pointless.* They'll outlive the gearing these days. Make sure you're rev matching though. That's not just for longevity but for performance and even saftey.
*Unless you're driving with an old transmission design.
@@CynHicks I always rev match, feels wrong not too lol
@@bradytharp8194 Both psychologically and physically right lol
Is that the same as floating gears?
@@CynHicks yeah lmao
Probably the only most Educational thing I’ve seen all day
You blipped after you put the car into the third on the downshift which defeats the purpose of double clutching. The point is to match the revs with the car in neutral and the clutch out so that it goes into gear easier. Even for the upshift, you let the revs fall too much which would work the synchros more. If you want to learn to do it correctly try to do it without the clutch. That will make you match revs correctly cause you can't just rely on syncros
This ^
I was hoping somebody would say it for me lol
Are u suggesting floating gears in a car
@@ishdeepsingh2960 yes. Or just drive a car without syncros
daily drove a 64 chevelle for years and i got to a point besides sitting at a stop i never touched the clutch, I got to a point where i could rev match perfectly every single time.
Something I haven't been able to understand for years explained perfectly in 10 seconds. Thank you.
Just shift like normal bit keep the throttle cracked so the engine is close to your target RPM for the next gear. I use this allot if I am wanting to keep the turbo spooled between gears on my 1.9TID as I can keep around 7-10PSI of boost going into the next gear instead of waiting for the turbo to come back up from 0PSI.
Those gearboxes love to be powershifted, last forever if you are under 400hp. Funny how you can bang all gears and they enter smoothly, try to put it in reverse while completly stopped and you feel it fighting you
Isn’t that rev matching
I have the alh what do you have i love mine 🤙
@@cadenjames442 i had a AHF loved it, pushed it to about 200hp, now have a ASZ and it has been flawless
Well thats why, with a 1.9TDI you aint pushing enough horsepower to hit 100mph. Let alone wear down the clutch 😭
im so glad someone finally explained it properly.
It’s easier to double clutch when you’re forced to. Like having worn synchros or driving a big rig.
Me right now haha the footwork go crazy when you're trying to do it quickly 😂
furry
This is true. First company out of trucking school has strictly manual trucks all with 1M+ miles. Never even drove a single manual car before this. Now 10 months later and an ungodly amount of grinding it comes naturally😅
@@reyesI165 lol I know the feeling, You just shift and hope you’ll end up in the right gear. But yeah in terms of manuals, it’s easier to learn to drive a semi if you haven’t driven a manual car before. I unfortunately learned stick on a Subaru so it was hard to be gentle on that poor freightliner
Double clutch on a semi?
Only in CDL school and on your test, once your on the road you float gears or curse the "genius" that invented automated/automatic transmissions.
Or you grind like hell and get stuffed into the one auto on a stick fleet (odds are, its transmission went out of production a decade ago so have fun with a transmission thats not quite all there in the computer)
But what you forgot to mention is you need to increase the rpm in between the shift to match the input shaft speed to the next gear speed. This is how you shift a big truck transmission. But what is easier is to just float the shift without touching the clutch.
Easier, but if you fail, you fail more spectacularly, lol
That's only for downshifting though
Thank you for, at the end, also telling the boy-racers it's totally unnecessary in modern gearboxes.
You don’t need to double clutch anymore as modern transmissions have synchros
That’s what he said…
Was taught to double clutch in trucking school. But all the big trucks have straight cut gears, allowing for clutchless ninja shifts.
It's not the cut off the gears that matter. Straight cut is just for strength but are noisy that's why cars have helicoil cut.
All gears are always in mesh, but are not in dog.
Cars have a synchro mesh in the dogs to speed up or slow down the gears to match the input and output Shaft.
in my 12 years truck driving i only ever used the clutch taking off lol. float em up and down, impress the DOT officer that rides with you when you get your CDL.
@@Robert-cu9bm thanks for clearing that up but all I know is if your fast enough you can slam all the gears in the low range.
Eaton wants you to double clutch
@@mr.nobody68They drive better once you learn how to float gears.
Double clitching is still a valid technique when dropping down from a high gear to a super low one, as it will reduce the wear you put on your synchros :)
On the upshifts, it still makes sense.
The transmission has lower frictional losses, thus it takes it longer time to "slow down". Engine has higher frictional losses, slows down faster. So by releasing a clutch in neutral, you are essentialy slowing down the transmission to the correct (slower) speed. This could be also achieved by upshifting slower, or letting synchros do the work.
On the other hand, when downshifting, the transmission will not speed up automatically (as opposed to slowing down on upshifts), so on downshifts, you release the clutch in neutral (while also revmatching) to get the transmission up to speed. This is far more "important" if you will.
So double clutching on upshifts is not nearly as important, but still makes sense, because you are not using the synchros to slow it down, but rather a clutch with the engine.
I'm glad to hear modern manual transmissions don't need to double clutch, that'll make it easier for me to get into using one 😂
Yeah don’t bother, it’s for driving a race car smooth so it last a long time but synchros are there for a reason. You don’t need to heel toe either but that one is actually a useful skill if the pedals are the right distance for your shoes
Almost nothing you have to do this in
Blip the gas in neutral to rev match?
U bleep it right as u let go of the clutch so rpms don't fall again while u shift
Only downshifting
Yes clutch neutral let go blip clutch downshift
What he said
almost like a motorcycle except don’t hold the clutch
Good explanation, you should rev match while the clutch is out in neutral though
The only man on the planet that knows what “granny shifting and not double clutching like you should” means
Anyone with a cdl should know this lol
uhh not exactly
@@jessemurray1757 yeah he’s a little off on downshifting
🤯🤯I never really cared to understand the term, but you packaged it so nicely. Thank you sir
On old sliding mesh tractors (I still use) it helps to double clutch, they can be very hard to put in gear on fhe move, but when it comes to disassembly of the gearbox, it's very simple relative to new gearboxes. 3 gears on the main shaft, 3 on the lay + reverse idler, high low box on an planetary 4:1 reduction, that's about it.
I used to have to do that in my ‘97 Sunfire after it lost Syncro in second third and fourth.
Double clutching is what destroyed the synchros
@@djjaysky9071 Interesting theory, is this opposite day? I bought the car with grinding gears and double clutched it to prevent it from grinding…
Your voice is so calming it was easy to understand
They always throw general car jargon in those movies, even when it doesn’t apply.
Tha k you for mentioning that it's not necessary in modern cars. Half the fools out there trying to double clutch to be cool and just adding more wear and tear on their shit. That being said, it's pretty cool seeing an old schooler do it super fast and proper.
yeah except double clutching still is helpful. putting less strain on your synchros = longer lasting synchros
@@QuincyStick Mines got a bad synchro on 5th and grinds. Double clutching it smooths it out everytime lmao. When i drives others cars, i double clutch 5th out of instinct.
@@QuincyStick if your synchros are failing then double clutching won't solve your terrible driving
@@GewelReal not all synchros are made the same. Some are made very poorly and give out fairly early. Also many people like to drive their cars for hundreds of thousands of miles, and synchros will wear out eventually on their own even with good driving, double clutching helps extend their life even further.
@@QuincyStick I'd rather get a new gearbox for 5$
This has bugged me for years THANK YOU!!
Unless your driving a semi double clutching is a waste of time. If you want to be nice to your transmission and make it last a long time slow your shifts down so your syncros arent working so hard to match gear speeds
Exactly what I was about to comment.
By slowing down your shifts you mean releasing the clutch slower or moving the gearstick slower?
@@slimyzombie the stick.
@@slimyzombie just revmatch
@@Moto848 imma stop you right there. Im a driver too. I know lol. i float my 10 speed 04 t800. Im just trying to point out that the only time you would double clutch is in an unsynchronized trans like a semis.
OH MY GOD, SOMEONE FINALLY PUT IT INTO WORDS!
When I prepared for my Class A CDL you have to double clutch for the test to show you know how to modulate the clutch. After I got my license I never double clutched again. Just clutch for start n stops then float gears which is way more fun.
Apples to oranges. Class A trucks are all unsynchronized AFAIK, where all class C vehicles are going to be synchronized transmissions. That being said any class A driver that's been on the road more than a week is going to float gears aside from maybe 1st to 2nd.
@@lumivar1719 was just relating to the video my guy. Most don’t even understanding floating gears let alone double clutching
@@tacotime07 yea I had to do the double clutch thing at the dmv to about 10 years ago😂😂
I was gonna get onto you at first. Then you went on to perfectly explain this. Great job
Some modern era cars didn't have syncros in 1st or their syncros are worn out. Double clutching has its place for down shifts, but not necessary in most situations.
Syncros are a wear item like brake pads, but they're inside the transmission. Keep that in mind...The more smoothly you shift and the more you double clutch to spin up that gear instead of letting the syncros do it, the slower they will wear.
But so is a clutch, and the clutch wears much faster. I've changed plenty of clutches and slave cylinders which required dropping the trans, but never synchros, so I wouldn't worry about those too much. I'd say let the synchros do the job they were designed to do.
Bro this made it click so much in my head. Glad I’ll be shifting better in my mustang tomorrow morning 😭🙏🏼
I used to DoubleClutch my Datsun i had back in the day. And from my experience is that every time i go into the new gear doing a DC it feels almost like my car had that little extra power. Now i maybe wrong but that was a lot of fun.😢 miss my Datsun.
That’s… not double d clutch. You’re supposed to rev match not clutch drop off the rev limiter.
This can still speed up your downshifts if you rev match perfectly. The goal is essentially to get your trans input shaft and clutch rotating at the exact speed they will be when the input shaft is locked to the output shaft. You have to do this on every downshift when youre floating gears otherwise itll grind and not engage at all. The synchros do this for you through friction, but a quick double clutch downshift is faster and much more satisfying. Double clutching on an upshift is counterproductive as ot increases the difference in speed between the input and output shafts making the synchros work even harder.
Theres exactly 0 good reasons to double clutch while upshifting....you know like a drag race.
Pretty sure they have straight cut gears.
@@yorkshire_tea_innit8097 Straight, helical, wooden pegs doesnt make a difference. An upshift requires the input shaft speed to slow down. This happens naturally when the clutch is pushed in so double clutching and allowing the engine to slow the input shaft down is redundant and a waste of time. The only time an upshift requires a double clutch is if you took too long to shift and the input shaft speed is now too slow.
Downshifting requires the opposite - to increase the input shaft speed. The only way to do this (besides syncros), is to rev the engine with the clutch engaged and transmission in neutral - double clutching.
Double clutch is still used on manual semi's. Float shifting is fun also.
Double clutching is one of those useless requirements to pass the driving part of the cdl test at the dmv😂😂😂 thats the only time I've EVER done it.
Jesus man it’s about time someone just explains it instead of going off on an extremely confusing 30 minute rant about how and why but never really explaining it right. You just get straight to the point short and simple. You have no idea how many videos I seen where they never explain it or it’s extremely confusing
to be fair he didn't really explain it here. I'd advise finding an in depth video actually explaining why and what it does and how it is still helpful even with modern transmissions.
Clearly stated easily understood. Thanks
So is it just a more complicated rev match ?
The video is explaining it is absolutely pointless unless you want to take longer to change gear
Synchronized transmissions are fun
My old s10 was great to let off throttle. No clutch, and just snap the shifter into the next gear
Ull grind a few times till u get hang of it. Then ull be powershifting. Almost instant gear changes
in Russian cars sometimes the car won't go into gear unless you double-shift. The gearboxes does have syncros but still you need to double-shift every now and then. Actually I had to do it yesterday on my driving test :)
How old is the car?
@@thehighvaluecat9313 2008 Lada Priora. Not that old. But it's also common on newer models
@@abdullahlibzo6914 wow that's crazy to hear newer cars needing synchros 😮. My oldest truck is an 85 and doesn't require double clutching. I did drive a 1931 Pontiac sedan with a three speed , that of course needed it 😂.
@@thehighvaluecat9313 Yeah I agree. The Pontiac must be a blast to drive, like you're in a time capsule
there are situations too do this, a worn transmission would prefer you treat it this way similarly too how old automatics prefer you rev with the shifting too reduce wear and increase efficiency
Double Clutching can save your sychros too. Especially if they are worn out
If upshifting, just push the lever into the next gear up but not fully, applying gentle pressure.
As engine RPM drop, the lever will happily pop into its spot, meaning the engine’s RPM has dropped enough to match the desired gear’s ratio, is spinning at just the right speed for the dogs to actually line up and be “synchronized” to the next gear, allowing the shift collar to slide along the main shaft, siding itself into the female end of the gear combo you’re selecting.
You never actually “shift gears”, theyre in constant mesh and are bevel cut for quiet operation.
What you shift is a 2-directional (back and forth) collar, with square-cut gears (dogs) with a brass or other soft metal synchro clutch on the outer circumference that fits into the gear combo’s friction ring, that slows down via friction (upshifting) or speeds up (downshifting) the engine’s input shaft speeds determined by the clutch engagement.
Actually there's still a benefit to double clutching a synchronized manual, as it reduces wear and tear on the syncros. This applies more to down-shifting, especially big down-shifts, like 5th to 2nd @55MPH, where the input cluster needs to be spun WAY up from say, 1800RPM up to 5500RPM. In the same way that rev matching reduces wear on the clutch, rev matching combined with double clutching reduces wear and tear on both the clutch and syncros.
FINALLY SOMEONE UNDERSTAND SYNCROMESH HOLY FUCK YOURE A GODSEND
Yeah but in sport and wrc cars they doesnt have synchos in geabox,because of that they have sequential shifters... and if you have dont have sequential and dont double shifting you beting the shit out of your gearbox...
double clutching extends the life of your syncro rings by quite a bit. the same premise from before is true. highly recommend when daily driving.
You missed the main reason to do it sir.
It's fun as hell once you have it down.
Non syncroed transmissions had a clutch brake, when you pressed the clutch pedal the clutch disk would stop spinning so the gears didn't grind. Double clutching ensured everything stopped completely. Modern syncros only stop the gears involved in the gear change from spinning instead of the entire gear cluster and disk.
This is wholesome, happy to see someone knowing their stuff :)
Double clutching in this reference is referring to the way a rally car driver does it. Where you push the clutch and high rev the engine while shifting
Actually bro, it still has it's uses with engine braking and hard stops or helping you NOT unset the balance of the car when slowing down for corner entry- you can effectively down shift at higher revs and not have to worry as much about compression lock ups
thanks. I've told many people that synchronizers eliminate the need to double clutch every shift, it's like talking to a wall
As a trucker we're taught to double clutch and in most schools you will fail your test if you don't but once you have your license you can float your gears
Honestly been double clutching like in the video and the car feels so much better
He's absolutely right. I've driven non synchro trucks.
However, we used to double clutch and rev up the engine when downshifting. Made a significant difference. Maybe still worth it in synchro transmissions if you are a huge racer :)
I like when he shifted, that was dope.
Double clutching is to avoid using the synchronizers to bring the engine up or down to speed while shifting gears.
Double clutching down in the lower gears, especially from 3rd to 2nd, or even from 2nd to 1st, is a great way to minimize synchronizer wear.
Also makes you sound cool. :p
Happy to finally learn :D
Yeah, when I saw F&F back in high school, I was confused why someone would double clutch in a drag race.
I think the writers meant when you press the clutch in while in low RPMs to get the flywheel spinning and drop it to get a little burst in speed. When you accidentally put it in too high of a gear it’s a nice little trick to get going.
Double clutch downshifting is only effective if you rev match while in neutral instead of rev matching while on the clutch. Otherwise you’re not actually synchronizing the clutch for the next gear
Doms got a 1930s transmission in his ride apparently
Eaton road ranger gearbox for trucks... double clutching is for strong /tough gear boxes.. not for cars..
Thank you for mentioning that it's not needed in newer cars. Some people don't know that
Fellow 350z owner here 👍
Floating gears is so much more satisfying!
My favorite part is they said that in the movie but the actors couldn't actually double clutch convincingly so in every scene I watched they all just shifted normally :P There would be some logic to double clutching when rapidly accelerating or decelerating while street racing since the synchros would wear out faster and the racers wouldn't be rebuilding their transmission after every race (or every few) like professional race teams often do.
Nice job of explaining. For me the reason of why would be for proper training clutch use giving the operator a feeling and understanding of how their trans operates after getting so familiar with it one might be able to float gears. Floating is a technique utilized by big rig drivers of down or up shifting without using the clutch, once this can be mastered it could be applied to a racing application which would be beneficial when left foot breaking (really common use for rally or touge runs). I think covering of floating would be good for you to cover.
There sre still valid uses for double clutching in a Synchromesh transmission. For example, when the transmission is cold, shifting to 2nd can be super notchy or outright grind. DCing will make the shift smooth guaranteed. Second, if you brake heavily and shift from a really high gear to a low gear, skipping many gears, the synchro is also gonna struggle shifting. DCing will, again, shift smoothly.
I like that it has cuts, probably paying attention to traffic and continuing the conversation once he has a second, or maybe it's just shorts and he cut out rambling. 😂
Still reduces wear on synchros *and* smoother shift felt through the car. Great when you have passengers, or have to skip 2-3 gears.
There's than just the synchro involved, and more disconnected than this gives credit for. I personally didn't like the the idea increased clutch wear, so I'd recommend clutchless deshifting for people that care for that
Adding on to what is said here... Some gboxes can't be quick shifted because it will either not select or start grinding so double clutching stops you having to wait for the speed of the gears to match hence why some old people sound like it takes them years to change gears!
"That just sounds like shifting with extra steps..."
Explained very well.
Bout time someone pointed this out. First time I heard him say that I knew they had no idea wtf they were talking about.
While I understand what he's talking about here, I don't think that's what the character meant in the movie.
I think what the character meant by "double clutching" was, in higher gears (3-6) after the initial release into that gear (when its just the motor pulling and bogs a bit), you pop the clutch in and go to redline and pop it out again in that same gear. While this can gain you a little time/speed, it is very hard on all of the components.
The screenwriters had no idea about modern cars
You rule dude - I knew what double clutching was and that some truckers used to do it but never knew why
that's why this line in the movie is so famous lol I love it
Rev match in neutral with clutch engaged. I always do it, even in sports cars, when going into low gears or downshifting down 2 gears at once. Saves the synchros
It is actually possible to drive a manual transmission without using the clutch at all. I have done it when the clutch mechanism has failed. Shift into neutral to stop, shut the engine off, select first and start the engine to get going. Lift off the gas as you pull through neutral into second. Lift off the gas for each up shift and for downshifting blip the throttle as you pull it through neutral into the lower gear. You can feel when you do it correctly and you can definitely hear when you messed up.
I always thought that line was funny cuz double clutching is legit granny shifting💀💀
Remember, "danger to manifold"? Sums up the movie pretty well
Try floating the gears. Way easier on the clutch and is overall satisfying
Finally after all these years
No you are not trying to synchronize the input shaft to the engine, you are matching wheel speed to your next desired gear.
So rev matching ?
Why bother with this then
It's also why semi truck transmissions say to double clutch, but outside of doing your driving test I've never seen any driver actually double clutch a newer Eaton Fuller. We us the clutch when at a stop to get the truck moving, or when going in reverse, any other time we are floating gears.
The clutch is for starting from a stop,or fanning to bring up rpm.
Fast and furious writers were never concerned with being accurate.