Who here knows how to heel and toe downshift

[Salvador]

Just curious how many people know how to heel and toe downshift.

Sal

 

[Colt45]

what, gas and brake with one foot?

 

[TechnoKid]

first off, the pedals have to be properly spaced.

 

[Zim Hosein]

Originally posted by: Salvador
Just curious how many people know how to heel and toe downshift.

Sal

I do

 

[Salvador]

what, gas and brake with one foot?

Yup..

Here's a video showing both heel and toe downshifting and double clutching (double de-clutching).

Heel and toe and double clutching video (small file)

Sal

 

[Brutuskend]

Double clutching and the Toe Heal technique aren't the same thing.

Double Clutching...

Now, if you have driven old cars, or trucks, or sports or racing cars, you will be amused at this play on words. That's because double-clutching is also a procedure to save wear and tear on your gearbox, and on your clutch, at the expense of a little extra work for your left leg. What exactly is double-clutching (or, as the British call it, "double de-clutching"), and why is it significant?

Let's say you're accelerating in second gear. When you're ready to shift into third, you decide not to use the standard approach, which is just to tromp on the clutch, take your foot off the gas, shove the shift lever into third, and let the clutch back out. Instead, you opt to double-clutch properly:

First, you take your foot off the gas and kick in the clutch. You shift into neutral, AND let the clutch out. You wait perhaps 0.3 to 1.0 seconds for the engine to slow down from its high revs, depending on how fast you were revving when you started to shift and how much inertia the engine has to slow down. THEN you kick in the clutch and shift into third, and let the clutch out quickly, feeding the gas appropriately. If you have judged it right, when you let the clutch out, there isn't any JERK. And when you shove the lever into third, the gears and engine are at a synchronized speed, so there's minimum wear on the synchronizers, which are the tiny clutches that bring the clutch plate and the gears into smooth synchrony. There's also usually less wear on the clutch plates.

What's the big deal? The main point is that when you try to shift into third gear, the engine has slowed itself and the clutch plate down to the right speed?just about the same speed as the gearbox?so it saves wear on the synchronizers and the clutch. It can also save shock and strain on the whole drive-train, because the speeds are just about synchronized when you let out the clutch.

Well, big deal, you say. Cars haven't needed double-clutching since the synchromesh transmission was popularized 50 years ago. Why bother? Why fool around with anachronistic motions? Isn't it just buying trouble? Even Tom and Ray Magliozzi* claim that double-clutching is silly and stupid and wasteful of energy. Ah, but I can give you reasons why it is beneficial.

First, in most cars, the actual gears are always in constant mesh, and the synchronizers only decide which pair of gears to connect to their shaft. But many trucks and some racing cars are still set up with a non-synchromesh gearbox. With trucks, because they have so many gears, it's noticeably more efficient not to have all of the gears in mesh all of the time. So with the "crash-box," you HAVE TO double-clutch, or you will not be able to shift. The same holds true for racing cars?to gain the last couple percent of efficiency, only one set of gears is in mesh at any time, and you have to actually synchronize their speeds or you can't get it in gear. Despite the obvious drawbacks of having to double-clutch, the gearbox is stronger and more efficient than a comparable synchromesh one, and has less tendency to overheat.

Other reasons for double-clutching: Because it is the right way to operate the clutch. Because it saves wear and tear on your synchronizers in the long run, if you're planning to run your car over 200,000 miles, as I do. Because it is fun to do. Because in very cold weather, (-10° F, for example) you may have to double-clutch to shift gears at all, at least for the first few miles.

One very important reason is that, if your clutch linkage ever fails, you can still shift and get home by double-clutching, getting the engine and gears' speeds synchronized and then just EASING the shifter into the right gear. In the last 1,050,000 miles of driving VWs, I have lost my clutch about 3 times, and each time, with careful planning, I've been able to drive home safely. One time I pulled into the Customs House at Calais, Maine, and discovered my clutch was out. I eased along carefully and managed to get all the way home, 350 miles, to Boston, where it was convenient to put the car in the shop to have the clutch repaired?much more convenient than in the middle of a vacation, or the middle of Maine.

Another reason is that on some old cars, first gear isn't synchromesh, so if you need to shift into first without coming to a full stop, you have to double-clutch. Also, a lot of cars these days are made with weak, chintzy synchros, so they soon wear out, and to drive them gracefully, you need to double-clutch.

 

[Aharami]

if my car's pedals were set race style., i'd love to do that

 

[TechnoKid]

Originally posted by: Salvador

what, gas and brake with one foot?

Yup..

Here's a video showing both heel and toe downshifting and double clutching (double de-clutching).

Heel and toe and double clutching video (small file)

Sal

tha vid just shows heel toe downshifting.....its just that the second half of the video, he downshifts two gears instead of one.

 

[geno]

why would you need to know how to double clutch, other than in case your syncros go out on you?

 

[JulesMaximus]

I do.

 

[Salvador]

first off, the pedals have to be properly spaced

Not really. There are different techniques that you use to heel and toe. If the pedals are spaced closely together, you can just use the right side of your foot (ball area of the foot) to blip the throttle. If the accelerator is further away from the brake, you can pivot your heel over to blip the throttle. This is the technique that I learned and use.

Sal

 

[Brutuskend]

Originally posted by: geno
why would you need to know how to double clutch, other than in case your syncros go out on you?

I used to blow up my clutch a LOT back in my street racing days. If you can double clutch, you can still get the car home when your clutch blows.

 

[spidey07]

I do and use it daily.

 

[Zim Hosein]

Originally posted by: Brutuskend

Originally posted by: geno
why would you need to know how to double clutch, other than in case your syncros go out on you?

I used to blow up my clutch a LOT back in my street racing days. If you can double clutch, you can still get the car home when your clutch blows.

You can also shift w/ out the clutch if you know what you're doing

 

[spidey07]

Originally posted by: geno
why would you need to know how to double clutch, other than in case your syncros go out on you?

it can make for a smother shift. Although not needed.

And not only that, its just plain fun.

 

[robphelan]

this is a requirement if you want to drive a 914

 

[m2kewl]

i do and use it on the wrx all the time...sweeet

 

[Brutuskend]

Originally posted by: Zim Hosein

Originally posted by: Brutuskend

Originally posted by: geno
why would you need to know how to double clutch, other than in case your syncros go out on you?

I used to blow up my clutch a LOT back in my street racing days. If you can double clutch, you can still get the car home when your clutch blows.

You can also shift w/ out the clutch if you know what you're doing

Exactly, that what I meant. :roll:

 

[Salvador]

Here's a quicker download for the 3 mb video file. The first half of the video shows a heel and toe downshift and the second half shows a (quick) double clutch.

Heel and toe video (faster connection)

Sal