Front Pads And Rotor Temperature

[Roy]

Has anyone actually inspected the temp paint on their DBA rotors to gt an idea of brake temps after a run at the track? If so can you post up some info such as car, rotor type and pad you are using?

Im looking at a few different options and looking to get as lower temp pad as possible since im hoping to run a basic, kind on rotor pad as a result of the rotor size and pad size of the new setup.

Im hoping i can almost go a basic pad like RB74. Essentially is a large 4 piston Brembo caliper running 343x32mm rotor with ducting. Will they see 400deg C. I want to run kiddy core pads to keep rotor wear and obvisouly pad cost down.

Even better if someone runs data logging and knows rotor temps whilst running

[Duncan]

sure....I ran:

dba 4000 series rotors

motul rbf6000

standard nissan pads

32 gtr calipers.

on the stagea for 25 laps at wakefield....and the paint didn't change colour lol

[Scooby]

sure....I ran:

dba 4000 series rotors

motul rbf6000

standard nissan pads

32 gtr calipers.

on the stagea for 25 laps at wakefield....and the paint didn't change colour lol

presumably you have to brake from over 60 kh/h before they will generate enough heat?

Edited July 23, 2007 by Scooby

[STATUS]

Speaking to a few sprint guys in adelaide on the weekend i was told that the dba rotors love cryo treating.... i never used cryo as everything i have seen it used on made zero differrence but the source of this comment was from a few respected guys... apparentley they were sceptical too but the braking distance change was measurable.

Any other experiences? just curious thats all.... maybe cryo is good for something. im not sure of the long term benefits but i imagine the heat cycles would have some long term effect over the initail cryo treatment...

[Ant97GTR]

Roy,

I managed to burn off the first two paint strips on my DBA5000's at sandown and they were tinted blue at the end of the day. I believe djr81 on these forums has more accurate temp data on the dba's used on sprint days in WA (I think!).

Oh and the pad I'm using is the SBS carbon/ceramic type....

[djr81]

Speaking to a few sprint guys in adelaide on the weekend i was told that the dba rotors love cryo treating.... i never used cryo as everything i have seen it used on made zero differrence but the source of this comment was from a few respected guys... apparentley they were sceptical too but the braking distance change was measurable.

Any other experiences? just curious thats all.... maybe cryo is good for something. im not sure of the long term benefits but i imagine the heat cycles would have some long term effect over the initail cryo treatment...

Cryo treatment is supposed to increase the fatigue resistance of the metal. I have no idea why someone would report better braking distances with a cryo'd rotor. Maybe it was one of those cases of the driver thinking he could confirm an improvement that wasn't really there.

Roy, with regard to temps. It is quite easy to get all three paint markers to flash off with RB74 pads. Same for DS2500's etc. Problem with the 74's is they don't recover after a good heat soak, the friction coefficient never seems to come back.

If you are running a larger (longer) pad this will help your temps as will a heavier rotor & ducting. Bottom line is the temps will depend on three things:

Rotor temp at the start of the braking zone.

Mass of the rotor.

Amount of kinetic energy being transferred to heat energy during the decelleration.

Basically compared to the amount of heat input you wont get any cooling worth a spit during the braking. On the straight after is a different matter, but not worth a spit compared to the heat input in the braking area.

You can do a rough calc by working out the kinetic energy loss & estimating how much of this goes into the front rotors. Get the mass (Not including the hat section) of the two front rotors & using the specific heat guesstimate a temp.

[Roy]

Looks like i will haev to discinnect the inlet temp from my data logger and run it near the brake rotor for a day or two

[STATUS]

Cryo treatment is supposed to increase the fatigue resistance of the metal. I have no idea why someone would report better braking distances with a cryo'd rotor. Maybe it was one of those cases of the driver thinking he could confirm an improvement that wasn't really there.

hence me asking the question, im the worlds biggest skeptic, only the reputation of said driver is held in high regard by many so i figured id ask around.

[Beer Baron]

I'm a big believer in troys goal here. having run everything from street pads, to endless carbon pads (CCR) I have to say that I have been able to get the paint markers to change, I have many, many times cooked my fluid but I have never had any real bad pad fade. so I am keen to try and run with lower temp pads in the hope of making my fluid last longer and rotors too. I think i just need bigger balls and more corner speed. but with pezzy brakes you find your self on them earlier, and longer and it just spirals down hill from there.

[t01-100]

I've used DBA5000 324x32 on a 260kw/1500kg GTR with standard Brembo calipers, 3" ducting and Pagid RS12 in one tarmac rally... the red paint turned white (cream) on the first stage, and two stages later they were warped with the same seen after each stage.

The same set up, the actual whole front brake kit (with skimmed rotors) including 3" ducting but with Pagid RS4/2 was then put on a 225kw/1100kg GTSt and even after a 10 lap race at Symmons Plains the green will go cream but the orange remains orange.

[t01-100]

Also, we only use Motul RBF600.

[T04GTR]

under race condition and undersized rotors/calipers. ie:99% of track day cars. 900 degrees is not uncommon. the v8 utes hit around 900+ well enough to make cp5555 6 pot calipers with ds3000 catch well and truly on fire after 4 laps of qr.

and also melt the alloy pistons in them.

dba 5000 series 330x28 last 2 rounds before they are cracked all the way though