New race pads?
#23
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We use PFC 97's and PFC11's (depending on availability) on our Chump Car and love them. Great feedback, easy to modulate, and not an aggressive initial bite (cuts down on flat spots). We easily get a 14-16 hour race weekend out of a set. Usually get another 7-8 race out of them after that. On my HPDE car, I usually get 2-3 full weekends out of them. Heating up and cooling them down kills their life expectancy.
#24
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Just swapped carbotech XP10 for G-loc G10 and they are better in quite a few ways. The G-loc don't have a groove in the center so they don't squeel quite as bad the carbotechs. The Carbo's dusted really badly but so far the G-loc isn't as bad. Pedal feels firmer but we'll see how they do at the next track session. At temp the Carbo's have a spring feel to them, not mushy but there is some travel to the pedal which once you're over the odd sensation makes them easy to modulate.
The GLOC's have a good amount more initial bite, you really need to sharpen your pedal feel quick or you'll be doing 200ft lockups. Dust wise they are about the same, I see no significant difference.
I thought about swapping back to my carbotechs but after a few events I've gotten the feel of the GLOC's down so I'll probably just stick with them now.
#26
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I've run the Cobalt and PFC and like them both quite a lot. My complaint with the Cobalt is the large rivets take up usable pad thickness, like 1/3 of it. Bonded pads like the PFC give you more life for the $$$. But these newer generation compounds are great.
#27
I like to change my pads right about that point anyway. The heat transfer to caliper gets greater when there is less pad left. That last portion also contains some of the bonding chemical and tends to behave differently than the first half of the pad.
#28
I have run Carbotech pads, way back before the current company owned them, the Hawk DTC pads (combination of 60 and 30 front and rear) and the Cobalt pads in my track car. My car sees similar abuse to an endurance car in that my Dad and myself share the car and one of us will run the car in one session and the other will run it in the very next session so the car sees very little break during the day.
I have zero experience with the current offerings from Carbotech and the pads I have run from the older company I would not recommend.
Hawk DTC pads are what we currently run on car and are very happy as the car does see street use and the DTC compound works at lower temps.
Cobalt Spec Miata pads are very good, but you need to be cautious when you get down to the end of the pad life, as they can start to crack and delaminate from the backing plates. Another note about the Cobalt pads is that they are designed to be run without the metal shims that a normal pad rides on to help aide in quick pad changes. A word of caution, if you switch from the Cobalt pads to another pad, remember to install these shims. I had a scary incident where my Dad changed the brake pads over to the Hawk DTC pads and did NOT install the shims. I was going into turn 1 at Sebring when the brakes almost stopped working, long pedal and hardly any brake force. I was able to get the car slowed down enough to make the corner and brought the car back to the pits. What we found when we torn the car down was down right scary! The pad moved enough without the shim to drop out of the slot that hold the tab on the pad (Thanks Sebring Turn 17!). So when I stepped on the brakes, the tab on the end of the pad was outside of the caliper bracket and only the rear section of the pad was making contact with the rotor. My pressing of the pedal harder and harder, actually bent the backing material (See attached picture).
I have zero experience with the current offerings from Carbotech and the pads I have run from the older company I would not recommend.
Hawk DTC pads are what we currently run on car and are very happy as the car does see street use and the DTC compound works at lower temps.
Cobalt Spec Miata pads are very good, but you need to be cautious when you get down to the end of the pad life, as they can start to crack and delaminate from the backing plates. Another note about the Cobalt pads is that they are designed to be run without the metal shims that a normal pad rides on to help aide in quick pad changes. A word of caution, if you switch from the Cobalt pads to another pad, remember to install these shims. I had a scary incident where my Dad changed the brake pads over to the Hawk DTC pads and did NOT install the shims. I was going into turn 1 at Sebring when the brakes almost stopped working, long pedal and hardly any brake force. I was able to get the car slowed down enough to make the corner and brought the car back to the pits. What we found when we torn the car down was down right scary! The pad moved enough without the shim to drop out of the slot that hold the tab on the pad (Thanks Sebring Turn 17!). So when I stepped on the brakes, the tab on the end of the pad was outside of the caliper bracket and only the rear section of the pad was making contact with the rotor. My pressing of the pedal harder and harder, actually bent the backing material (See attached picture).
#30
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If you're down to the rivets you need new pads, plain and simple. We usually do 1 set of rear pads/rotors a year, and one set of pads last ~8 hours. Depending on the track sometimes we can reuse the front
rotors, other times we'll need new rotors. The cobalts will work amazing right down to the backing plate, we've done it a number of times.
If you're not choosing cobalts for rotor wear reasons, you need a hpde pad, not a race pad. VERY different requirements.
rotors, other times we'll need new rotors. The cobalts will work amazing right down to the backing plate, we've done it a number of times.
If you're not choosing cobalts for rotor wear reasons, you need a hpde pad, not a race pad. VERY different requirements.
#33
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These pads only looked about half worn or maybe a little more from the top but there was an awful grinding metallic sound and it was eating the **** out of my rotors. So I pulled them out to inspect and lo and behold I was grinding the tops off of gigantic ******* rivets. So this means that if I decide to run a Cobalt pad I need to stay at least an eighth of an inch off of this thickness which means that I'm using about half the pad that I would if I had to stay an eighth of an inch off of one that was just bonded. Does that make any sense to anybody?
*eighth of an inch by eye is my emergency minimum.
*eighth of an inch by eye is my emergency minimum.
#34
Not to mention the chunking you were getting.
For comparison, this is how thin you can run carbotechs.
Brakes felt fine on the last lap on track, I knew I was pushing my luck. What's interesting is the pad taper you see here, it's not typical pad taper in that the leading edges is cooler than the trailing edge. This was caused by the caliper rotating on the pins, wearing the trailing edge on the back of the caliper and the leading edge on the front pad. It's not a lot but enough to want non floating calipers.
For comparison, this is how thin you can run carbotechs.
Brakes felt fine on the last lap on track, I knew I was pushing my luck. What's interesting is the pad taper you see here, it's not typical pad taper in that the leading edges is cooler than the trailing edge. This was caused by the caliper rotating on the pins, wearing the trailing edge on the back of the caliper and the leading edge on the front pad. It's not a lot but enough to want non floating calipers.
Last edited by Bronson M; 07-21-2017 at 11:39 AM.
#38
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It's been a couple of years, but the chunking may have been damage that occurred when I was using a Flathead screwdriver to lever the pads back to leave room for the insertion of new pads. I seem to vaguely recall removing them to inspect them and then returning them to the caliper to assist in gently leveraging the Pistons back.
#40
Something else is going on there. I've never seen chunking like that and I've run my pads a whole lot thinner. Curious about rotor size, temps etc. Also what compound.
If the PFC's don't chunk like that then you got a solution that clearly works. We had great results with em on the E36.
If the PFC's don't chunk like that then you got a solution that clearly works. We had great results with em on the E36.