I have a track day coming up and I wanted to get some feedback on whether I should replace my pads now, pre event. The pads seem to be 50%, or the same thickness as the back plate, but I am far from an expert. Does anyone know at what thickness the sensors get triggered? @ 10%? 25%?

These are original to the car and are OEM. I have 24k miles on the odometer. I have already done 4 DE days on these pads - 2 last summer, 2 this summer. I dont think I am very aggressive on the track with my braking. I dont expect to become more aggressive.

Also, In the 2nd pic, you see grooves in the rotor (much more pronounced in the pic due to zoom and light). The rotors have absolutely no cracking and no "lip". Whats causing these and should I replace the rotors as well with new pads?

Thanks

 

If it were me I'd put new pads in. Also be aware they can wear unevenly. You are looking at the trailing edge, the leading edge could be thinner. IIRC the new thickness is 11mm (not positive) so you are maybe 30% maybe less. Most DE organizers require 50% or more on their tech forms. Discs probably ok but should be checked for thickness to be sure.

 

For track use, I'd replace them when they get to 50% because you cut down on the heat transfer from the rotors to the brake system when things get hot. Grooving is normal but should be present on both sides.

I'd replace the pads - its quick to do and its good insurance when you need them at 130 mph.

 

Thanks. Out of curiosity, when the brakes are as thick as the backing plate, they are NOT at 50%?

The grooving is present on both sides. Rotors present no lip and are not visually thinner than new ones...

 

I replace pads when then get to same thickness as backing plate for the reason Frank mentioned.
Your disks show no signs of cracking between the drilled holes. So, if they are within specs as far as thickness goes they seem good.

 

The backing plate is approx 4mm thick so for fronts if the remaining pad is the same thickness you are at 4/11= 36%. I once tried to stretch a set of pads that had maybe 25% visually. Second session second day I reached the backing plate. Turns out the pads weren't wearing evenly. On the way home I thought- man was that stupid, reaching 130+ on the main straight and trying to stretch a set of brake pads. Never again, not worth the risk.

 

Thanks for the feedback, made an appt @ my indy to swap them out.

 

Yep new pads for sure!

 

Thanks Mdrums

 

Have your indy teach you how to do it. Very easy. Good skill for the track.

 

I sort of know how to do it I did it most of it myself last time @ my indy on my .1S while he was on one of his smoke/coffee/girl staring breaks. But I have no tools and no garage, so I go there and "help out"