HOW TO STOP GRANNY SHIFTING AND START DOUBLE-CLUTCHING LIKE YOU SHOULD  

Exactly bro, finally someone who knows what they are talking about.

i literally uttered "but why" and he immediately said "the better question is why". Man's one step ahead

Granny shifting feels like a more appropriate term for this double clutch method lmaoooo

Was taught to double clutch in trucking school. But all the big trucks have straight cut gears, allowing for clutchless ninja shifts.

Synchros: Invented in 1919 People in 1918:

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.

It’s pretty hard to double clutch on a motorcycle. Going 110 than shifting all the way to neutral than 6th gear

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.

Careful, you might blow the welds on your intake and your floorpan will fall out.

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.

A good way to shift when your synchros are fucked 😂

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.

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).

You should also mention double clutching is used when downshifting while decelerating hard and you want to stay in gear for the upcoming acceleration.

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.

Something I haven't been able to understand for years explained perfectly in 10 seconds. Thank you.

Imma let my synchros take care of it

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.

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

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.

Blip the gas in neutral to rev match?

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.

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.

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.

It’s easier to double clutch when you’re forced to. Like having worn synchros or driving a big rig.

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.

The only man on the planet that knows what “granny shifting and not double clutching like you should” means

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.

Thank you for, at the end, also telling the boy-racers it's totally unnecessary in modern gearboxes.

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

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.

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 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 :)

They always throw general car jargon in those movies, even when it doesn’t apply.

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.

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

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

im so glad someone finally explained it properly.

Your voice is so calming it was easy to understand

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 😂

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.

Good explanation, you should rev match while the clutch is out in neutral though

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.

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

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.

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 :)

So is it just a more complicated rev match ?

Double clutch is still used on manual semi's. Float shifting is fun also.

Theres exactly 0 good reasons to double clutch while upshifting....you know like a drag race.

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.

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 :)

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

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

Bro this made it click so much in my head. Glad I’ll be shifting better in my mustang tomorrow morning 😭🙏🏼

Double Clutching can save your sychros too. Especially if they are worn out

Probably the only most Educational thing I’ve seen all day

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

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 never really cared to understand the term, but you packaged it so nicely. Thank you sir

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

This is wholesome, happy to see someone knowing their stuff :)

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. 😂

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!

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

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.

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.

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.

Clearly stated easily understood. Thanks

The approval rate of this video is alarming.

I was gonna get onto you at first. Then you went on to perfectly explain this. Great job

I like when he shifted, that was dope.

this is just extra steps, you want to shift as fast as possible, clutch in, shift out, shift in, clutch out, this is the fastest and most reliable way to shift, less steps, less time, less chance to screw up

I always thought that line was funny cuz double clutching is legit granny shifting💀💀

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.

Remember, "danger to manifold"? Sums up the movie pretty well

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

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 recommended, and taught, to double clutch while driving a Semi truck. Not really that hard once you get use to it. Just have to beat the RPMs. However, after a bit, you can just float the gears.

thanks. I've told many people that synchronizers eliminate the need to double clutch every shift, it's like talking to a wall

Happy to finally learn :D

FINALLY SOMEONE UNDERSTAND SYNCROMESH HOLY FUCK YOURE A GODSEND

You rule dude - I knew what double clutching was and that some truckers used to do it but never knew why

OH MY GOD, SOMEONE FINALLY PUT IT INTO WORDS!

Finally after all these years

Also, rev matching takes a lot of the load off of the syncro, so if you're rev matching, you're helping it do it's job and taking better care of your car. Rev match > double clutching. On a motorbike though, neutral means you fucked up, and you'd better start working that toe lol

that's why this line in the movie is so famous lol I love it

Honestly, to be fair feels more like a dig that he drives old American muscle cars and Brian was driving modern imports.

Only other point is if you were to block shift down multiple gears in a car with a lot of turbo lag. Doing it straight would be extremely hard without upsetting the cars wheel speed and breaking traction but the double clutch allows more time under breaks before reaching the new gear without needing to go thru each on the way down

Synchronesh means all the gears inside the transmission spin together, and the output shaft only connects to one at a time, the chosen gear. Not related to the synchronizer mechanism which matches the speed of the chosen gear to the speed of the output shaft for effortless shifting.

I remember my first time driving a Morris Traveller and a Morris Commercial from the 1920s. They weren't fun experiences, well.. they were, but not for the transmissions, it's very difficult to transition from being used to syncromesh and vice versa when you've been driving one type of vehicle for a long time.

Doms got a 1930s transmission in his ride apparently

Thank you for mentioning that it's not needed in newer cars. Some people don't know that

I was laying down on the floor drunk in my room when this song came on 💆🏽‍♂️it hits home ❤

Fast and furious writers were never concerned with being accurate.

Technically what you're really doing when you recouple the clutch is synchronizing both the input shaft and, more importantly due to its mass, the countershaft. It is still important to do during spirited driving in a synchronized transmission because it significantly reduces wear on the synchronizer rings, especially if you have a stock clutch and flywheel. I mean, unless you really, really like taking your transmission apart to press the gears off and replace synchronizer assemblies 🤣

Correct, but that's not why in this case. Miss your shift on an import with a 7k-8k red line and you spin that shaft so fast you won't get it in gear without grinding even with sychros. In this moment there are three good choices: 1. Stay in neutral and stop pulling 2. Granny shift so you don't grind 3. Let the revs dump and double clutch that B with perfect timing for the fastest recovery that won't blow your trans.

Now "double clutch" without the clutch. I did it. I smoked the clutch in my S13 & it locked up, so it could not disengage. Then I drove it for several weeks while waiting on replacement parts. It had to be started in 1st gear, then it couldn't be stopped while in gear, or be put in gear while stopped & running. Every gear change required rev matching to wheel speed for whatever gear was desired.

If you have ever driven a HALF automatic. Yes, half.... which is a car with a stick shift, but without a clutch. You become really good at listening to the engine to shift gears when need. You also ether increase the throttle a bit at first and release \ reduce it just before switching gear to get a natural flow between the gears.

Funny thing is, semi manufacturers, kenworth at least if I recall, state to not use the clutch and float it instead. Only using the clutch when starting from a stop.

Honestly been double clutching like in the video and the car feels so much better