"Left foot braking"

[Martin]

Pressing the brake at the same time as the accelerator causes the ECU to ignore the accelerator input.
However, if you press the accelerator whilst braking, the accelerator input IS processed

We have software we have developed in conjunction with APR that has enabled "Left foot Braking" particularly for DSG motorsport applications, but it's available at no extra cost (on request) with the APR tune at initial installation.

Why would one wish to do this?

Another point we haven't covered, specific to motorsport
Prior to arrival at a corner it's entirely normal to use the left foot to jab the brake peddle
This is to check if there are any brakes and to deal with "pad knock off" (push the pads right up to the disc)
If you've clobbered the apex the impact can knock the pads back from the rotor disc
Next time you go to hammer the brake at the very last second you will get a long peddle and may not make the corner (certainly not the apex)

You could not do this in a race if the ECU shut the throttle down when you jab the brakes

[Tobes_WIR35]

My left foot must be mildly retarded. I can't even brake smoothly at a red light with my left foot, let alone do it on a race track!

[Martin]

It's something you have to tune into and get used to...

[wai]

My left foot must be mildly retarded. I can't even brake smoothly at a red light with my left foot, let alone do it on a race track!

Don't worry, the muscles in your leg need training

If you want to use left foot braking, you need to practice and practice. If you find yourself having to change to left foot braking, it is a great incentive to train

[Tom87]

I learnt to left foot brake in recreational 4wding as my vehicle at the time had an extreme distance between the pedals and when wearing hiking boots it could be a bit clunky to use.

I now find myself doing it every day in traffic. There's not alot of benefit, except perhaps faster reaction times when stopping but that is hardly a major issue, I'm not a tailgater.