Brakes not effective

[Dudders]

Hi all,

I have a speed passion ESC with a control box for set up. Just found the time and courage to have a fiddle as I wanted more brakes on neutral.

However, I think I've set up everything to maximum and still the car rolls. Surely in neutral (or a little reverse stick even) it should stop the drive wheels in an instant.

What am I doing wrong?

All words of wisdow and other greatly welcomed as it reet doing my nut in!