I think you have missunderstood my post. I in no way said a heaver car will corner faster. In fact it will corner worse because again assuming two similar cars with differing weights. The cornering ability will be determined by the lateral grip of the tyres. The lateral cornering force of the car is produced by two things, weight and speed. Assuming the lateral grip of both cars is the same the heaver car will reach its limit at a slower speed. This can be linked to the formular Force = Mass X Acceleration.
Now, It is not like saying a sumo can stop quicker than a Jockey. This example has nothing to do with the subject. The key things here are that the tyres are the same, the brakes do not fade, and both cars brake at maximum ability.
What I dont think you are taking into account is that the heavy car will have to dissapate a LOT more heat than the lighter car. This has nothing to do with the maximum coefficient of friction available from the tyres, weight on the other hand does.
Another example would be when you brake in a car with the same tyres on the front and back, if you set up the brakes so there was no bias then you did the 100 to 0 test what do you think would happen? The answer is that the back wheels would lock up. This is because when you brake the weight of your car shifts to the front. This is the reason why there is bias set into a brake system.
I hope this makes sense.