I think I was around 7,000rpm in my car doing about 187mph (approximately) 5 spd 4.11 Final Drive w/ JDM Evo 8 5th gear.

 

BBK Full. It will hold much more, but I’m just running less for the track (and because 93 octane).

 

I guess I was thinking the external reservoir was helping. It’s better than before when I had huge brake delay at the end of long straightaways. Still improving. Is it possible the added ABS is unable to keep up with 10/10ths driving on wider R7’s? Thinking about unplugging ABS and comparing. Need to see if ABS is coming on to soon? Or not allowing peak threshold braking. Maybe new Radical AP Pro 5000’s are also stressing the ABS program???? I should start a new thread on this. You experienced the same ever?

 

Yep sometimes, get tons of laps of it not doing it, then the one hard pedal but still braking. It's enough of an issue that it makes me count 1 1thousand before applying brake after my super long straights. I've also adopted jackie stewarts driving style of easing both instead of immediate threshold braking up front followed by immediate gas. Makes it much more predictable and faster because you don't overslow or underslow. This is not caliper related.

 

Getting vacuum in the brake booster is different than the manifold. My car without a vacuum pump shows vacuum just as quickly in the intake. Only time I have hard pedal is autocross, or if i get into abs

The vacuum pump helping brakes makes sense. I thought you had it running on the crankcase for additional ventilation.