One of the joys and delights of a true sports car is the manual transmission. In addition to allowing the driver to be in control of the gear-selection process, manual transmissions generally provide superior fuel economy and performance than automatic transmissions. It is essential, however, to know the “proper” way to shift a manual transmission to enjoy these advantages while enhancing driver/passenger comfort.
Virtually everyone knows how to upshift a “stick,” but downshifting is an art that few Americans seem to know how to do well. In particular, very few drivers today double-clutch (or “double de-clutch”), which is also known as “matching revs” between the engine and transmission. Most drivers, when downshifting, merely press in the clutch after letting off the throttle, jam the stick in a lower gear, and then let out the clutch. In modern vehicles, this is possible with synchromesh transmissions, but is usually accompanied by a sudden rearward weight transfer, if not any less-than-harmonious engine/transmission noises. To the occupants, especially the passenger, this jerkiness can be annoying, and in spirited driving, this sudden weight transfer can have an adverse effect on handling. Perhaps more importantly, however, is that the life-span of the synchromeshes may be shortened with this practice. The solution, then, is to double-clutch!
To double-clutch during a downshift, perform the following steps:
- Let off the throttle, press in the clutch, and shift the “stick” to neutral.
- Let out the clutch.
- Bump the throttle to make the engine “blip.” Sometimes in my MG I’ll press in the accelerator all the way to the floor for a fraction of a second.
- Press in the clutch.
- As the engine speed decreases to match the transmission speed, throw the stick into the next lower gear. Since you actively “matched the revs,” it should fall right in!
- Let out the clutch. The downshift should have been as smooth as butter!
Note that Steps 1-6 are actually performed in a split-second. To start double clutching for the first time, you may perform the steps slowly. However, with practice, everything becomes second-nature. In addition to saving wear-and-tear on the transmission, double-clutching sounds cool (due to the throttle-blip) and shows the passenger that you are an “adept driver.”
Heel-Toe Downshifting: Braking + Double-Clutching
Another advanced technique is heel-toe downshifting. Heel toe downshifting is a variation of double clutching, but is performed while the car needs to slow down quickly (as in the approach of a sharp corner). More precisely, heel-toe downshifting is double clutching, except that you are braking at the same time! The name comes from braking with one’s toes while blipping the throttle with one’s heel of the same (right) foot. Admittedly, this technique takes a lot of coordination and practice!
Actually, most MGs (and other British cars for that matter) seem to have the pedals optimally placed for heel-toe downshifting. Some people even “enlargen” the accelerator pedal by installing a “Paddy Hopkirk pedal” on top of it or by, say, replacing the smaller accelerator pedals of a chrome-bumpered MGB with a longer one from a rubber-bumpered B, in order to ease heel-toe downshifting. At least with my ’69 MGB, however, I find that the stock setup is more than adequate, and much better than other cars. For example, on my Porsche 944 Turbo, it is impossible to “heel-toe” with the heel and toes, due to the lower placement of the accelerator pedal and its floor-mounted pivot point. In this case, the most effective method seems to be to “heel-toe” with the inside of the right foot on the brake, and the outside of the right foot blipping the throttle. Of course, this “inside-outside” technique can be used on an MGB too, although I find that the more traditional “heel-toe” method allows for more pedal travel and more “throttle blippage.”
If you enjoyed this article, please consider receiving my weekly newsletter. I typically write about endurance bicycling, world travel, self improvement, Colorado living, marathon running, and epic adventures.
Articles related to How to Double-Clutch and Heel-Toe Downshifting
- Other posts about Sports Car Motoring