Double clutch shifting, what does it entail?

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We used to do a lot of double-declutching in very cold weather. (There is no cold weather where we live now).

My wife would get into the habit and continue well into the summer. It's not hard when you get the hang of it.
 
Originally Posted by hallstevenson
I think it was Olas that said it above, you use your fingers on the gear selector, not grab it firmly and slam it between gears. .....Do it so lightly that you can feel when it will slip in nicely. No racing-style, heel-and-toe or throttle blipping is really needed with practice.

I've heard it described as "wishing it into the next gear". I do it all the time - two fingers on the gear lever. I know how to shift fast, I just don't do it.
 
I double- clutch going down into 2nd whether the car needs it or not. If I don't need to, I still save wear on the synchros.
 
First off, double-clutching is not for synchronized transmissions that work properly. A reference to double clutching was stupidly put into the first Fast & Furious movie, but those writers didn't seem to know Richard about cars.

It's for old non-synchronized gearboxes. Often you will find it's only first gear. I just bought a 51 Ford and you only double-clutch first.
 
I had read about double-clutching and didn't really get the point until I let the gear oil get low on a leaky 1986 Jetta. I guess it cooked the synchros, because after that you had to double clutch downshifts into third. I developed the habit, might still do it. Upshifts were just a matter of being sensitive with the gear shift.
 
Rev Match is a cool technology, so is GM's no lift shift. My last three tremec equipped cars I could drive without using the clutch, upshift, downshift. It's not hard if you know the feel and aren't afraid to boss the shifter around.
 
Originally Posted by Dadillac
Every time I read about people double clutching any trans that has synchros I just shake my head.

Don


Especially on the track...
smirk2.gif
 
Originally Posted by MCompact
One of my first HPDE instructors told me to practice heel-toe on the street so that it would become second nature on the track. I still do it 100% of the time in my Club Sport- and even in the Wrangler.


I instruct all of my HPDE students in rev-match downshifting. It is fundamental to road course driving technique.
I feel sorry for people with flappy paddle gearboxes...
I learned rev-match downshifting out of the Bob Bondurant book in 1985, and have used it ever since. I used to do double-clutch downshifting, but stopped because it is wasted motion on modern gearboxes. Single-clutch rev-match downshifts are what I do in all my vehicles. It blows peoples minds when they ride with me in my diesel pickups.
 
Originally Posted by ecotourist
Originally Posted by hallstevenson
I think it was Olas that said it above, you use your fingers on the gear selector, not grab it firmly and slam it between gears. .....Do it so lightly that you can feel when it will slip in nicely. No racing-style, heel-and-toe or throttle blipping is really needed with practice.

I've heard it described as "wishing it into the next gear". I do it all the time - two fingers on the gear lever. I know how to shift fast, I just don't do it.


Don't watch a YouTube video of Ronnie Sox powershifting his Cuda! Drag racing is abusive only if its done right.
 
Originally Posted by Gasbuggy
First off, double-clutching is not for synchronized transmissions that work properly...


You say that with an air of sureness. To which I answer: Double-clutching is only for synchromesh transmissions with knackered synchro's that were caused by someone NOT double-clutching (down)... especially 2nd gear synchro's.

Hey, YMMV. You drive the way only YOU know best; I will drive the way I know is best.
 
Originally Posted by Cdn17Sport6MT
Originally Posted by Gasbuggy
First off, double-clutching is not for synchronized transmissions that work properly...


You say that with an air of sureness. To which I answer: Double-clutching is only for synchromesh transmissions with knackered synchro's that were caused by someone NOT double-clutching (down)... especially 2nd gear synchro's.

Hey, YMMV. You drive the way only YOU know best; I will drive the way I know is best.



Double Clutching on a downshift seems pointless, all you'll be doing is forcing the synchro's to work overtime trying to make up for that idle RPM your engine will fall to while you're spending all that time pushing the clutch in and out twice. You'll be forcing 2nd or whatever gear to catch up to. An intelligent foot on the throttle is what a well-timed downshift needs to minimize the wear and tear. Maybe you're doing both.
 
But I don't let the rpm fall to idle. I raise the rpm to (at least) the point where it needs to be in the lower gear (and, foot-on-the-throttle) I leave it at that rpm and keep driving at that same rpm after the downshift from neutral is made. It's not a blip; it's a raise-and-hold. And, you need to make a decisive (i.e. quick) clutch-in, shift from neutral to the lower gear, clutch out "move" or the rpm of the counter shaft WILL fall... so sometimes you partways overlap those steps... like shift out of neutral at the clutch-in half-way point. Proof is in the pudding; doing this, gear lever force is 'real low... which says the synchro is not working hard at all. I grant you that selecting the correct rpm takes practise and knowing your car well.
 
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The other comment to make - i.e. doing this on a track at a Driver's Ed. session: if you are braking, you do it while braking [i.e. you "heel-and-toe (an incorrectly named process 'cuz it doesn't involve your heel)] - and so it doesn't take up any additional time because you have to brake during that time anyways. Having said this, it's not easy to do. In Porsche circles, cars with their PDK are quicker on the course because i) their pdk's are so intuitive (left in automatic) and drivers can then concentrate solely on lines and car control and ii) their pdk's shift quicker than the manuals. Saying this, it's not always JUST about speed. Really mastering a good manual trans is pretty gratifying.
 
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