Left-foot braking in autos
Discussion
Andrew Noakes said:
Inspired by the thread on heeling and toeing, a question: when you're driving an automatic (or an assisted manual - anything with only two pedals) do you brake using your left foot?
And if not, why not?
No - it isn't necessary, and the pedal layout is such that it's easier to shift the right foot between the Go pedal and the Stop pedal as necessary.
The only reason I can think of when you'd want a foot on each pedal is to get a good drag strip launch - rev up to the torque converter's stall point while holding the car with the left foot on the brake, then foot off and away you go! I don't think it would work on mine, though - the ECU cuts fuel if the brake pedal is pressed.
I drive a Semi-Auto (yes, it's a smart...) so tend to left foot in that, mainly because the gearbox is rather shoddy, so being able to blip the throttle between gears on the downchanges makes things a hell-of-a-lot smoother.. Obviously the likes of Ferrari & Lambo do this for you, but not smart... ohh no..
slinky
slinky
I have a Tiptronic/Auto car and the manual clearly states that you should not use your left foot as you should either be using the 'go' or the 'stop' pedal. Using both feet could mean depressing both pedals at the same time - even inadvertently - and this can cause transmission problems and wear.
iguana said:As spoken by someone who has never driven a TVR Griffith in heavy traffic.
Surely if you are in posession of a left foot you don't own an auto in the first place?
Think I should carry out a survey at BTaP to see if the left thighs of TVR drivers are bigger than their right. I know mine is about 6 mm bigger.
IMHO left foot braking plays a similar role in autos as in manual cars, i.e it allows you to optimise cornering by a progressive transition between throttle and brake (blending one into the other) which avoids the unsetttling effect of having to come right of the gas in order to get on the brakes. There is therefore a much less abrupt shift of c of g so less pitch change and more stability (less change in handling balalnce), additionally because there is still power at the rear wheels there is less chance of locking up the rear on an entry to a corner.
I always used that technique in my XJS V12 (with the GM400 auto 'box - before i converted it to 5sp manual)when pressing on, and I found that it tranformed cornering stability making for very rapid and relaxed progress.
PS: it gives the brakes a good work out, esp on a 1700kg behemoth! So good brakes essential.
I always used that technique in my XJS V12 (with the GM400 auto 'box - before i converted it to 5sp manual)when pressing on, and I found that it tranformed cornering stability making for very rapid and relaxed progress.
PS: it gives the brakes a good work out, esp on a 1700kg behemoth! So good brakes essential.
Andrew Noakes said:
Why not?
iguana said:
Nothing in response
As I thought
You thought what? that I may have perhaps have had better things to do this wk end than to log on to PH?
Anyway if you like autos fair enough each to their own, personally I detest driving them vs a manual especially on a car with any sporting pretentions, hence while I have the use of my left leg I see no reason why I would wish to have my driving joy spoiled by an auto box.
For some reason, I instinctively left foot brake in automatics.
In the US there is the sport of autoxing which is a timed negotiation of a course marked by road pylons. Speeds are usually less than 60mph (2nd gear) and I use LFB in front drivers to aid pointing the car at turn in and to settle the chassis in slalom sections.
The Kicker though:
The last time I tried LFB in anything that was drive-by-wire though, the ECU would cut power severely.
Mk4 GTi and 996 are two examples.
m
In the US there is the sport of autoxing which is a timed negotiation of a course marked by road pylons. Speeds are usually less than 60mph (2nd gear) and I use LFB in front drivers to aid pointing the car at turn in and to settle the chassis in slalom sections.
The Kicker though:
The last time I tried LFB in anything that was drive-by-wire though, the ECU would cut power severely.
Mk4 GTi and 996 are two examples.
m
It doesn't work in the latest BMW autos (electronic throttle, so it assumes that if you're braking you cannot also be accelerating). It's possible in my M3 CSL (semi-manual) but I still prefer braking with my right foot and using the heel-and-toe method. Even though I've many years experience of kart racing I still prefer braking with my right foot, not least because the driving position of most modern cars would make it very uncomfortable to left foot brake (unlike a kart where your legs are straight out in front).
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