Raybesto ST-43 chunking problem
#1
Pro
Thread Starter
Raybesto ST-43 chunking problem
I did a bed-in one night doing the whole routine of 40-10mph, 60-10mph, and a few of 100-40mph. Anyways I went the next day (after bed-in) to an autocross and ran about 10 times on them with a warm up before the sessions. there was a section of braking from 97 to about 35 mph. This is my first set of race pads so i am not sure if i did something wrong or what could of caused this.
Info/input would is welcome!
Front right pair
Rear
A close-up of the front
Info/input would is welcome!
Front right pair
Rear
A close-up of the front
#2
Instructor
Seeing the combination of a little bit of glaze plus the chunking is unusual, but both are symptoms of improper bedding. Not sure how many cycles of the low speed stops you did, but those starting speeds look a bit unaggressive for race pads. It's possible you didn't get the pads and rotors hot enough on the original bedding attempt and then overheated them too quickly during the race (escaping gases caused chunking). The morning after I bed-in my race pads, there is still a very slight smell similar to burnt pad around the car. Did you notice anything the next morning?
Only other thing I can think of would be if you used new/unseasoned rotors when you bedded the pad??
Only other thing I can think of would be if you used new/unseasoned rotors when you bedded the pad??
Last edited by CONE RACER; 03-26-2013 at 10:57 PM.
#3
Drifting
I can't imagine autocross getting enough heat for st-43s. I run them and they don't fully come in until the 2nd session of 20 minutes on the track.
#4
Pro
Thread Starter
Seeing the combination of a little bit of glaze plus the chunking is unusual, but both are symptoms of improper bedding. Not sure how many cycles of the low speed stops you did, but those starting speeds look a bit unaggressive for race pads. It's possible you didn't get the pads and rotors hot enough on the original bedding attempt and then overheated them too quickly during the race (escaping gases caused chunking). The morning after I bed-in my race pads, there is still a very slight smell similar to burnt pad around the car. Did you notice anything the next morning?
Only other thing I can think of would be if you used new/unseasoned rotors when you bedded the pad??
Only other thing I can think of would be if you used new/unseasoned rotors when you bedded the pad??
Will this chunking and glazing greatly decrease the of these pads? Anything i should do before running them again? I do have another set of rotors i could bed them in on.
#6
Pro
Thread Starter
Yea, i kinda figured. I have them for when I go to Sebring, but I cant afford to do that all the time. I would use my street pads for Autocross but when i have my hoosiers R6's on I feel like the brakes cant slow the car fast enough for those tires. Its just having fun with what I have. Just seeing if i could do my bedding better or if doing autocross will ruin these pads faster than normal.
#7
Safety Car
my guess is that you are asking too much of these out of their desired heat range, but that is a total guess and may or may not have any truth. I have not seen chunking on these pads, other than (from what I remember), cracking off a decent chunk of pad (only discovered when changing sides to avoid taper) due to cooking them.
I have been through at least 4 sets of these pads, used gently on the street and pretty mercilessly on the track. Always, though, with the proper bedding (one perk of the street driving).
I have been through at least 4 sets of these pads, used gently on the street and pretty mercilessly on the track. Always, though, with the proper bedding (one perk of the street driving).
#9
Race Director
As others said, not an autox pad, but they don't look all that bad to me. Make sure you clean any glaze off the rotors & try again. You should be able to examine the rotors after bed in for a proper transfer layer, maybe bed in more aggressive next time. Ck mfg recommendation for bed in procedure.
#10
The rotor doesn't look bedded. You should have the grey color on the inner half too. I dont think you got them hot enough. The factory pads have plenty of bite for a A6, let alone and R6. It's just the heat they cant handle.
You aren't getting these pads up to operating temperatue and they change friction as they build head. Lower temp pads (like the factory pad) would be more consistent corner to corner and may help you go faster. Unless you are hot lapping an autocross course, I dont think it's possible to overhead a factory pad at autocross, even a 97 MPH course.
You could try a lower temp race pad. I run pads with less bite than the factory pads with my A6's. That helps me modulate the brake. They have plenty of bite, I just have to push harder.
You aren't getting these pads up to operating temperatue and they change friction as they build head. Lower temp pads (like the factory pad) would be more consistent corner to corner and may help you go faster. Unless you are hot lapping an autocross course, I dont think it's possible to overhead a factory pad at autocross, even a 97 MPH course.
You could try a lower temp race pad. I run pads with less bite than the factory pads with my A6's. That helps me modulate the brake. They have plenty of bite, I just have to push harder.
#11
Race Director
The rotor doesn't look bedded. You should have the grey color on the inner half too. I dont think you got them hot enough. The factory pads have plenty of bite for a A6, let alone and R6. It's just the heat they cant handle.
You aren't getting these pads up to operating temperatue and they change friction as they build head. Lower temp pads (like the factory pad) would be more consistent corner to corner and may help you go faster. Unless you are hot lapping an autocross course, I dont think it's possible to overhead a factory pad at autocross, even a 97 MPH course.
You could try a lower temp race pad. I run pads with less bite than the factory pads with my A6's. That helps me modulate the brake. They have plenty of bite, I just have to push harder.
You aren't getting these pads up to operating temperatue and they change friction as they build head. Lower temp pads (like the factory pad) would be more consistent corner to corner and may help you go faster. Unless you are hot lapping an autocross course, I dont think it's possible to overhead a factory pad at autocross, even a 97 MPH course.
You could try a lower temp race pad. I run pads with less bite than the factory pads with my A6's. That helps me modulate the brake. They have plenty of bite, I just have to push harder.