While doing some spirited driving on one of my favorite roads, I noticed after 5 or 6 heavy braking sessions that the brake pedal started to feel pretty spongy. They went back to normal after a few minutes. Is this normal? BTW I am driving a 05 G35x with aftermarket EBC redstuff pads and slotted rotors.

 

When was the last time you change the fluid out? Could be air in the system and or the lines flexing.

 

not since i replaced the brakes about 8 months ago

 

I have ebc redstuff pads and ebc slotted and drilled rotors and they bite best after some hard braking when they are nice and hot.

 

Its normal your brakes just got to hot and when they cooled down they went back to normal. You can try a higher boiling point brake fluid and slotted or drilled rotors.