# what is double clutching



## Guest (Sep 6, 2002)

simple question what is double clutching.


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## Adam (Apr 30, 2002)

obsolete.

Nowadays it's much easier to do heel-toe downshifting. Basically the idea of double clutching is to push in the clutch, put the car in neutral, let the clutch out, press it in again, blip the throttle, put the car in a lower (usually) gear, let out the clutch. As you can see, a waste of time when you can heel-toe by pressing in the clutch and rolling your foot over to hit the gas for the blip, then drop it in gear and let the clutch out.


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## hagasan (Aug 5, 2002)

I think it was a technique for gearboxes with no synchros...
......like old trucks and the like...and you had to do it while up-shifting too...


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## bahearn (Jul 15, 2002)

Double-clutch goes like this:

depress clutch pedal
place transmission in neutral
release clutch
blip throttle
depress clutch pedal
place transmission in next lower gear
release clutch

The idea is to have the transmission input shaft rpm (at engine speed) match the transmission output shaft rpm when selecting the next lower gear. In the days before synchronizers, not following this procedure for downshifting would lead to a grenaded tranny.

Racing places an addition demand that the downshift occur very quickly.

With the advent of synchronizers on all forward gears, the objective becomes to match input and output shaft speeds so as not to accidentally apply engine power or braking that would upset the chassis under heavy braking or cornering loads.

Heel-and-toe is a two-footed technique for double-clutching that demands three feet at one time. It's not actually heel and toe but rather braking with the big toe and/or ball of the foot while rolling the ankle so that the right side of the foot can also press the accelerator.

Thankfully, B13s have decently-placed pedals so that heel-and-toe can be done easily. Surprisingly, my 1990 Chevy S-10 truck had well-placed pedals for heel-and-toe while my '86 Shelby Charger Turbo did not.

Double-clutching has no real benefit on the street but it does sound cool (IMO) when done properly.

For a real double-clutch challenge, attempt it with a motorcycle where you're steering, clutching, braking and blipping the throttle with two hands while shifting and braking with two feet without losing concentration on where you want to go.


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## Adam (Apr 30, 2002)

bahearn said:


> *Heel-and-toe is a two-footed technique for double-clutching that demands three feet at one time. It's not actually heel and toe but rather braking with the big toe and/or ball of the foot while rolling the ankle so that the right side of the foot can also press the accelerator.
> 
> *


Doh, I knew I was missing a pedal in there somewhere. What I meant was



> you can heel-toe by pressing in the clutch with the left foot, brake with your right foot, and rolling your right foot over to hit the gas for the blip, then drop it in gear and let the clutch out


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## sr20racer (Jun 29, 2002)

It's what Brian L. Spilner does when he races


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## Guest (Dec 3, 2003)

*beneficial*

ok, so basically double clutching does nothing at all for the city driver.

What if you do what adam said.

"As you can see, a waste of time when you can heel-toe by pressing in the clutch and rolling your foot over to hit the gas for the blip, then drop it in gear and let the clutch out."

Would this be fasting that just gearing down and letting the syncro's do the work.

btw im a newb so be gentle.


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## Greg200SE-R (Feb 5, 2003)

Double-clutching is cool but single-clutching is easier to match revs and perform smoothly. It can be done a lot faster too. A simple throttle blip while the shifter is in transition is all you need. A heel-toe downshift is simply a single-clutch while braking. 

By the way, don't believe the "granny-shifting not double-clutching like you should be" B.S. from Fast and the Furious. Anyone who would double-clutch during a 1320 is pretty 420.

Just go out and practice single-clutching during your regular daily driving - in no time you'll know the RPM ranges for each gear to perform it smoothly. When you have that down, heel-toe downshifting will be easy... assuming your pedal placement is ok. I had to adjust my pedals to make heel/toe easy.

If you plan to compete in any motorsports events with corners, being able to single-clutch and heel-toe effectively will become much more important. Like you said, they're not especially useful on the street but its fun and it shows how well you know your car when you can do buttery-smooth transitions between gears!

Single-clutching, if done right, saves your synchros and clutch as compared to downshifting, clutching-out and letting the synchros do the work. The only thing is you won't slow down as much from engine-braking.


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## Blank (Aug 21, 2003)

bahearn said:


> Double-clutch goes like this:
> 
> depress clutch pedal
> place transmission in neutral
> ...



lol double clutching on a bike is arush, the sound, the speed...damn these buffalo winters...


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