At Oponeo, we believe there is much more to manual gearboxes than upshifting and downshifting. Here’s our take on the most popular gear change techniques – try them on for size and step up your shifting game.
What is double declutching?
In order to truly understand double declutching, we must first familiarise ourselves with the holy trinity involved in the technique; the engine output shaft – our source of power; the clutch – our means of transferring that power to the transmission; and the transmission output shaft – what makes the driven wheels go round. Each of these systems is able to rotate independently.
With double declutching, the driver goes into neutral before shifting to the next gear to reduce wear on the transmission. This increases synchronisation between the three systems as they rotate. Here’s how to properly perform a double declutch downshift.
- Begin braking.
- Engage the clutch. The engine output shaft is now rotating independently, while the transmission output shaft and the clutch still have the same rotation speed.
- Shift into neutral. This makes the clutch and the transmission output shaft rotate independently.
- Release the clutch with the transmission still in neutral. Now the engine output shaft and the clutch have the same rotation speed.
- Raise the engine RPM with the accelerator. This matches the rotation speed of the engine to the speed of the transmission output shaft.
- Engage the clutch once more and shift from neutral into the lower gear.
- Release the clutch.
And now for the bad news; since the majority of modern passenger vehicles use synchroniser rings, today’s drivers are no longer forced to match their engine revs for each gear shift. So, unless it’s literally your job to drive vehicles without synchronisers, such as heavy-duty freight trucks, chances are double declutching may not be of much use to you. But there are carryovers.
Heel toe shifting
With the invention of the synchromesh gearbox and semi-automatic transmission, double declutching may have become somewhat obsolete. Nevertheless, proficient operation of the clutch and knowing when to change gears remain functional skills to have in your arsenal, especially when it comes to the heel and toe technique.
Hailing from the competitive realm of motorsports, heel toe downshifting enables drivers to combine rev matching and braking as they approach a corner to maximise traction and keep their wheels from locking.
It all sounds perfectly fine in theory, but only through practicing heel toe shifting will you be able to reap the benefits. With that being said, this technique is a little harder to master than double declutching, and you may even flood your engine a few times before you get it right. If that happens, take a short break before proceeding with further training.
Here’s how to execute a flawless heel toe downshift in a synchromesh transmission. Before you begin, however, make sure you have the right tyres for the job. Also, please note that while double declutching can be incorporated into heel toe shifting, the prevalence of synchronisers makes that procedure unnecessary for most drivers.
- Begin braking using the ball of the left side of your right foot.
- Use your left foot to engage the clutch.
- As you depress the clutch pedal, swing the heel of your right foot and ‘blip’ the accelerator, simultaneously shifting through neutral into the lower gear.
- Release the clutch. The speed of the release will depend on how sensitive your clutch is, so make sure you have a good feel for it first.
Changing gear without the clutch
If you ever need to change gear without using the clutch, you should know that it is possible to do so with a technique known as clutchless shifting. This is not advisable, however, as aside from being harsh and damaging to your transmission, it is rather difficult to complete.
- When upshifting, it is crucial you let the tachometer run a little higher than usual – around 3500 RPM should do the trick. Once you get there, simultaneously take your foot off the gas and shift into neutral, then shift to the next gear and allow the engine RPM to drop.
Be careful not to apply too much pressure against the shifter, as this will cause the gears to grind. Likewise, applying too little pressure may lead you to miss a gear. Once the engine RPM matches the transmission speed, the shifter will slide into place.
- When downshifting, let your tachometer fall to around 1500 RPM by slowly releasing the accelerator, then go into neutral. If you find it difficult to shift, lightly tap the accelerator.
Once you’re in neutral gear, rev the engine to around 3000 RPM, then shift to a lower gear. Let the RPM drop slowly to allow the engine speed to match the transmission speed. The shifter will slide into place once that occurs.
Strengthening your gear shifting skills is not a quick process. You can only become a consummate expert through real world practice and learning, but you must prioritise safety at all costs. Learn at your own pace, and as you go on, you will gain more confidence.