^^^Exactly...you've found the limit.
What tires are you running??
DON'T pull that fuse (46) and expect to stay on track. (or anywhere near on track)
I tried that a month ago at a threshold braking excercise during our test and tune.
While I got out of the hole like a bullet (no TC),
the instant I hit the brakes the car turned 90° sideways since the rears locked up immediately.
Again, I stress...never ever try this on a road course or autocross,
and expect your car not to sustain massive amounts of damage as you leave the course.
The ABS is nothing short of phenomenal on the SVT, especially with the given large rotors.
I'll bet your tires are the limiting factor at the moment, which is why I asked what you were running.