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How to Double DeClutch or "double clutch"

"Double clutch downshifting"

Double clutch (or double declutch):-
Before cars had synchromesh everyone had to double clutch shift, now the only place you'll find this method is usually in motor sport today.

This is not the same as the heel and toe gear shift - a method described in this article.

So how do you double clutch gear shift and what is it?

To change gear, you press the clutch, move to neutral, release the clutch match engine speed to new gear speed with a throttle blip if changing down, depress the clutch and engage the next gear.

The obvious question is WHY DO THIS? How does this method work and is it better than a single clutch gear change on a modern car fitted with a synchromesh? Does it still have a place in modern driving techniques.

How to double de-clutch.

For example on the up change 1st Gear to 2nd gear -

  • Clutch down gear to neutral,
  • Clutch up still in neutral
  • Match transmission speed to engine rpm by pausing, RPM is a little lower when changing up
  • Clutch down then select second gear.

Changing down from 4th to 3rd gear.

  • Clutch down gear to neutral,
  • Clutch up still in neutral
  • Match transmission speed to engine rpm by pressing the throttle, RPM is higher when changing down
  • Clutch down then select second gear.

On cars with lightened flywheels a double de-clutch still has merit as the engine revs will dip quickly and may need to be increased. It really depends on the engine and the amount of revs involved at the time of the gear change.

Double clutch gear shifts comes into its own really when down shifting.

Some may blip the throttle with their heel while braking with their toe to achieve this, particularly down changing on a track coming into a corner.

Try this with a standard single clutch gear change first matching the engine speed with the new gear speed with the clutch depressed, when you have mastered this start to practice the full double de clutch moving the gearbox into neutral.

When cornering at high speed a rough gear change upsets the balance of the car so a double clutch avoids this.

TorqueCars were told of one site which recommended practicing the double clutch gear change in a stationary car with the engine switched off which kind of defeats the whole object of matching the engine speed with the next selected gear speed.

When perfected, this method takes as much time as a conventional gear change but maintains very smooth and progressive power delivery essential on track days or even in icy or slippery conditions. Other gear change techniques including keeping the throttle fully down during the gear change (power change) to keep the turbo spooling and power up.

Finally the method most drivers use, is depressing the clutch, changing gear and using the cars synchromesh to match the engine speed to gear speed. (Granny shift)

On modern cars with synchromesh some people argue that the double de clutch (or double clutch) is no longer of value and others say that it is what proper drivers on a track do. It will reduce wear in the gearbox and transmission and keeps things smooth. 

Why do it - its much smoother - when cornering at 100mph+ on a track a typical rough gear change could upset the balance of a car. It keeps the engine revs up on down changes, so on a tight bend you do not lose traction or power and the engine is already pulling in the next gear through the apex of the bend. 

On a drag strip where you just want to get the car to the top speed then the power change has a place but you still risk wheel spin and loss of traction with this brutal method.

We're really interested in the overall debate as to whether this method still has value today in the modern car. I feel that it does on the track, especially if the car has been tuned and the revs drop off quickly, and if learned properly can keep the car in good working order and it is a habit you can master on the open road. Please join us in the forum to discuss this topic further.

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2 Responses to “Driving tips for the track: Double de clutching”

  1. Mwelwa Kasanda says:

    I came to know this art or way of driving a truck without using the clutch in such a manner that people used to see as if I was driving an auto – matic truck whilst not.

  2. Martin says:

    I am 69 and have a Subaru BRZ.I am surprised that if you drop it into 5th from 6th it will crunch at anything over 3500RPM. I’ve always double de clutched down and have been trying to get out of the habit but since I like to shift to 5th from 6th at 100MPH which is way above 3500RPM I think I’ll stay with the habit.

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