Measuring Braking Temps
Aug 22, 2016, 02:48 PM
#31
Non-contact IR temperature sensors won't give proper temperature readings on brake rotors unless you get the emissivity settings in the right ballpark. The emissivity values for iron are all over the place depending on the state (Shiny, freshly turned, rusted, etc. http://www.engineeringtoolbox.com/em...nts-d_447.html ) so your IR thermometer readings can differ from reality a bit. In practice the error may be minimal, but it's worth double-checking against a known-good contact thermometer.
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rawkus (Aug 22, 2016)
Aug 23, 2016, 07:40 AM
#32
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Check out this CF thread - http://www.corvetteforum.com/forums/...e-cooling.html
Sep 12, 2016, 07:08 AM
#33
I tried the IR gun thing but after the cool down lap it doesn't even matter what it reads. I don't know what temps the DBA rotors have for temp paint but I got all of them white, and practically put my brakes on fire at my HPDE yesterday. Boiled the fluid too, pedal to the floor, smoking, smoking brakes, and turned my calipers nice and dark brown...
Not at a track known for destroying brakes - Autobahn South, though I do know a couple of people that lose their brakes going from 10-11. I probably won't be going back out without some major brake revisions, it's just no fun otherwise. I thought as a relatively novice driver in an HPDE I'd be okay but guess not
::edit::
the red strip on the dba rotor is for ~1200F, so I know I was going at least that hot if not over - can the ST43 handle that temperature?
Not at a track known for destroying brakes - Autobahn South, though I do know a couple of people that lose their brakes going from 10-11. I probably won't be going back out without some major brake revisions, it's just no fun otherwise. I thought as a relatively novice driver in an HPDE I'd be okay but guess not
::edit::
the red strip on the dba rotor is for ~1200F, so I know I was going at least that hot if not over - can the ST43 handle that temperature?
Last edited by kyoo; Sep 12, 2016 at 07:21 AM.
Sep 12, 2016, 07:44 AM
#34
Which likely means you were closer to 2k and I assume no ducting. 43's are technically a middle weight pad made for ~2500 lbs cars so they make great rear pads or for normal DE days. But I'd opt for ST47's in the fronts in this case and add ducting. Or slow down 
.
.
Sep 12, 2016, 08:06 AM
#35
No ducting - I have the MR air guides but one of them broke off at an autox lol. that's actually the side where the caliper turned nearly black too. sigh.. have you guys found a solution/hi temp paint that can handle or do you just leave the calipers brown?
Is there any way to know what brake fluid to get as well, or is it just, if it boils, you need better? i'll be going with Castrol SRF the next time I get out there but man I don't know if I will for a long, long time.
Also wondering as far as pad recovery - i.e., how do pads handle heat cycles? or should I just toss these pads? The brakes feel like total mush right now. I boiled the first session, skipped the second while bleeding, and then went out lightly for the third. on the way home, total mush. I guess i'll have to rebleed, but I'm wondering if the pads are ruined? the rotors I'm assuming were built to handle this kind of thing, and maybe just need to be rebedded.
Sep 12, 2016, 09:55 AM
#36
that's the thing I was kind of getting at - how do I know I was at 1200, 1400, 1800? And that a 1850F pad won't work, etc.
No ducting - I have the MR air guides but one of them broke off at an autox lol. that's actually the side where the caliper turned nearly black too. sigh.. have you guys found a solution/hi temp paint that can handle or do you just leave the calipers brown?
Is there any way to know what brake fluid to get as well, or is it just, if it boils, you need better? i'll be going with Castrol SRF the next time I get out there but man I don't know if I will for a long, long time.
Also wondering as far as pad recovery - i.e., how do pads handle heat cycles? or should I just toss these pads? The brakes feel like total mush right now. I boiled the first session, skipped the second while bleeding, and then went out lightly for the third. on the way home, total mush. I guess i'll have to rebleed, but I'm wondering if the pads are ruined? the rotors I'm assuming were built to handle this kind of thing, and maybe just need to be rebedded.
No ducting - I have the MR air guides but one of them broke off at an autox lol. that's actually the side where the caliper turned nearly black too. sigh.. have you guys found a solution/hi temp paint that can handle or do you just leave the calipers brown?
Is there any way to know what brake fluid to get as well, or is it just, if it boils, you need better? i'll be going with Castrol SRF the next time I get out there but man I don't know if I will for a long, long time.
Also wondering as far as pad recovery - i.e., how do pads handle heat cycles? or should I just toss these pads? The brakes feel like total mush right now. I boiled the first session, skipped the second while bleeding, and then went out lightly for the third. on the way home, total mush. I guess i'll have to rebleed, but I'm wondering if the pads are ruined? the rotors I'm assuming were built to handle this kind of thing, and maybe just need to be rebedded.
Secondly on the fluid - you've already read about that - Torque, Endless, SRF, Amsoil are all good choices. Make sure you bleed the clutch too if switching of course. Once a fluid boils ya it'll be mushy pressure. Your pad doesn't create the mush since it's a solid material right - it would be stiff but just not "grip" if it were the pad.
Pad wise the only thing you need to worry about if it's done is Glazing. Google that up but if it is glazed it'll be hella loud usually and it won't work right - kinda like overheating softer slicks - they just don't come back to that optimal performance level. Some pads like Hawks like to literally fall apart at that point but Ray's are much stouter.
Brownbo solution is to replace the brownbo with something better or to try and mitigate it with the aftermarket parts - ss pistons, better seals, etc. But i wouldn't worry about that yet cause that's just paint. Focus on your driving then better ducting/fluids/etc and do the calipers last if all that fails.
Sep 12, 2016, 09:57 AM
#37
EvoM Guru
iTrader: (1)
Holy **** man. Whats pads and fluid were you running?
I don't overheat my ST43's and I'm running ~130whp more than you on track, and I'm on NT01's. For ducting, all I have is the stock undertray installed (it kind of has channels in it to guide air to the brakes) and the Mitsu air guides as well. I have the Racing Brake one-piece directional vane front rotors, centric slotted (straight vane) in the rear.
My calipers are brown for now, supposedly powder coat handles high temp quite well.
I hate calling out driving skill, but how do you use the brakes? Extending the braking zones because you're not confident in braking hard and late actually makes your brakes run hotter.
I don't overheat my ST43's and I'm running ~130whp more than you on track, and I'm on NT01's. For ducting, all I have is the stock undertray installed (it kind of has channels in it to guide air to the brakes) and the Mitsu air guides as well. I have the Racing Brake one-piece directional vane front rotors, centric slotted (straight vane) in the rear.
My calipers are brown for now, supposedly powder coat handles high temp quite well.
I hate calling out driving skill, but how do you use the brakes? Extending the braking zones because you're not confident in braking hard and late actually makes your brakes run hotter.
Sep 12, 2016, 09:58 AM
#38
As usual lots of points to cover lol. So the first obvious bit is you know you're overheating since there's no air getting in there - fluid and pad aside - solve that first.
Secondly on the fluid - you've already read about that - Torque, Endless, SRF, Amsoil are all good choices. Make sure you bleed the clutch too if switching of course. Once a fluid boils ya it'll be mushy pressure. Your pad doesn't create the mush since it's a solid material right - it would be stiff but just not "grip" if it were the pad.
Pad wise the only thing you need to worry about if it's done is Glazing. Google that up but if it is glazed it'll be hella loud usually and it won't work right - kinda like overheating softer slicks - they just don't come back to that optimal performance level. Some pads like Hawks like to literally fall apart at that point but Ray's are much stouter.
Brownbo solution is to replace the brownbo with something better or to try and mitigate it with the aftermarket parts - ss pistons, better seals, etc. But i wouldn't worry about that yet cause that's just paint. Focus on your driving then better ducting/fluids/etc and do the calipers last if all that fails.
Secondly on the fluid - you've already read about that - Torque, Endless, SRF, Amsoil are all good choices. Make sure you bleed the clutch too if switching of course. Once a fluid boils ya it'll be mushy pressure. Your pad doesn't create the mush since it's a solid material right - it would be stiff but just not "grip" if it were the pad.
Pad wise the only thing you need to worry about if it's done is Glazing. Google that up but if it is glazed it'll be hella loud usually and it won't work right - kinda like overheating softer slicks - they just don't come back to that optimal performance level. Some pads like Hawks like to literally fall apart at that point but Ray's are much stouter.
Brownbo solution is to replace the brownbo with something better or to try and mitigate it with the aftermarket parts - ss pistons, better seals, etc. But i wouldn't worry about that yet cause that's just paint. Focus on your driving then better ducting/fluids/etc and do the calipers last if all that fails.
Holy **** man. Whats pads and fluid were you running?
I don't overheat my ST43's and I'm running ~130whp more than you on track, and I'm on NT01's. For ducting, all I have is the stock undertray installed (it kind of has channels in it to guide air to the brakes) and the Mitsu air guides as well. I have the Racing Brake one-piece directional vane front rotors, centric slotted (straight vane) in the rear.
My calipers are brown for now, supposedly powder coat handles high temp quite well.
I hate calling out driving skill, but how do you use the brakes? Extending the braking zones because you're not confident in braking hard and late actually makes your brakes run hotter.
I don't overheat my ST43's and I'm running ~130whp more than you on track, and I'm on NT01's. For ducting, all I have is the stock undertray installed (it kind of has channels in it to guide air to the brakes) and the Mitsu air guides as well. I have the Racing Brake one-piece directional vane front rotors, centric slotted (straight vane) in the rear.
My calipers are brown for now, supposedly powder coat handles high temp quite well.
I hate calling out driving skill, but how do you use the brakes? Extending the braking zones because you're not confident in braking hard and late actually makes your brakes run hotter.
thanks for mentioning driving - it's obviously one of the biggest factors. I do think it's partly due to technique, but not because I'm extending zones. I had an instructor ride along with me twice, and said I was actually braking too late and too hard - dive bombing into corners a la autox if you will. I think in the future I need to actually be gentler with the brakes, and maybe be on them longer and lighter than what I'm doing now. Before I boiled I was scooting closer and closer and later and later via the markers until the brakes gave out. BTW - this was over a 15 minute session, lol
Last edited by kyoo; Sep 12, 2016 at 10:09 AM.
Sep 12, 2016, 10:14 AM
#39
EvoM Guru
iTrader: (1)
My brakes go 25-30 minutes just fine at Spring Mountain Running the Mansel layout, which 3 heavy braking zones from 120-130 down to 75ish, and 1 from 125 down 50. And then the other 10 turns lol.
There is for sure a sweet spot between braking too early, and braking too late. Also, running a non-track pad is a big issue. It cannot dissipate the heat like a real track pad, so everything runs hotter.
There is for sure a sweet spot between braking too early, and braking too late. Also, running a non-track pad is a big issue. It cannot dissipate the heat like a real track pad, so everything runs hotter.
Last edited by letsgetthisdone; Sep 12, 2016 at 12:24 PM.
Sep 12, 2016, 11:25 AM
#40
thanks man!
pads were girodisc s/s - I know it's not a track pad, figured for a novice hpde I'd give it a shot. fluid was a mix of redline and napa lol, tried to get as much napa out as I could though before the event. I have stock plastic undertray, and the air guides with one broken off. DBA 5000 front, 4000 rear, with girodisc titanium shims. steel lines all around including clutch.
thanks for mentioning driving - it's obviously one of the biggest factors. I do think it's partly due to technique, but not because I'm extending zones. I had an instructor ride along with me twice, and said I was actually braking too late and too hard - dive bombing into corners a la autox if you will. I think in the future I need to actually be gentler with the brakes, and maybe be on them longer and lighter than what I'm doing now. Before I boiled I was scooting closer and closer and later and later via the markers until the brakes gave out. BTW - this was over a 15 minute session, lol
pads were girodisc s/s - I know it's not a track pad, figured for a novice hpde I'd give it a shot. fluid was a mix of redline and napa lol, tried to get as much napa out as I could though before the event. I have stock plastic undertray, and the air guides with one broken off. DBA 5000 front, 4000 rear, with girodisc titanium shims. steel lines all around including clutch.
thanks for mentioning driving - it's obviously one of the biggest factors. I do think it's partly due to technique, but not because I'm extending zones. I had an instructor ride along with me twice, and said I was actually braking too late and too hard - dive bombing into corners a la autox if you will. I think in the future I need to actually be gentler with the brakes, and maybe be on them longer and lighter than what I'm doing now. Before I boiled I was scooting closer and closer and later and later via the markers until the brakes gave out. BTW - this was over a 15 minute session, lol
Sep 13, 2016, 09:38 AM
#44
EvoM Guru
iTrader: (1)
The Ti shims are a bandaid for the OEM calipers using aluminum pistons instead of stainless. If you upgrade to the stainless racing brake pistons, there would be no need to run the Ti shims.