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View Full Version : Cool and Unusual Brake Info...LOOK!



mattmartindrift
08-14-2002, 11:35 PM
Well @ the mid ohio grand am cup race this weekend, we had our brake engineer from stoptec out @ the event. I learned some really neat things i'd like to share. Well first Air is enemy!!!, Have you ever blown on an almost extinguished camp fire only to have the black coals glow red again, well same thing w/ calipers when used on a warm track day. Air in moderation is good, smaller brake ducts, restricted flow, etc. . Also Black is good!...for all of you w/ painted calpers, take em off and paint them flat black, black disipates heat better than any other color.

Matt

**DONOTDELETE**
08-15-2002, 08:46 AM
Friction in the brakes shouldn't really have nething to do with combustion(like in coals which are fuel) i dont think, so I'm not sure that argument is really sound?

Why does black dissipate heat better?? I haven't seen any race cars with black calipers..

**DONOTDELETE**
08-15-2002, 10:23 AM
Hmmmm... then why not just drill holes through the slid parts of the calipers and run water lines through them if caliper heat is that "unwanted". Just a thought.

ruf4play
08-15-2002, 11:01 AM
Liquid-cooled brakes are commonly used in WRC tarmac stages. It's all about the operating temperature of the pad/fluid. You want the pad to be hot enough to work, but not so hot that it scorches the rotor or fades. You don't want it ever to get hot enough to boil the fluid.

As for black disappating more heat, I suppose it does. It naturally absorbs and radiates heat better just like white reflects better. You typically don't see race brakes painted ANY color because the paint itself probably retains more heat than anything else. Painted calipers are typically for show, so if you're going to paint them at all, I guess he's saying paint them black. Otherwise leave them bare or maybe anodized.

YellowS14
08-15-2002, 12:26 PM
paint is for show, if your going to put a purpose intended heat extractor coating on then swains black coating(dont remember the name)is the stuff id use, its the same coating thats used on compressors and intercoolers(SCC's sr20det swap info the fwd infinity)

YellowS14 http://forums.freshalloy.com/ubbthreads/images/icons/smirk.gif

White_240sx
08-15-2002, 03:11 PM
</font><blockquote><font class="small[/img]In reply to:</font><hr />
As for black disappating more heat, I suppose it does. It naturally absorbs and radiates heat better just like white reflects better.

[/QUOTE]

This only applies to heat energy from light though, I doubt color pigment has a very large effect on conducted heat if at all.

mattmartindrift
08-15-2002, 10:52 PM
This was all told to me by the 2nd in command engineer @ stoptec brakes, from California, they shipped a guy out to our race as we were having trouble on our race cars, and he told us these little hints. Also as for coals being fuel that was the example he used to me, but what about the adhesives in the pad itself? I've seen it ignite on more than one occasion w/ our cars pulling in w/ glowing rear rotors, as soon as the car stops, the pads ignite.

Matt

**DONOTDELETE**
08-15-2002, 10:55 PM
the bottom line is that brakes are gonna get hot no matter what, as long as you stop in time who cares.. just my opinion.

mattmartindrift
08-15-2002, 11:21 PM
Well of course, but in a race you need to stop in time for upwards of 6hrs. w/ 160mph to 50-60mph all the time, and you think brakes get hot on the street seeing pads ignite...that is hot, our fire extinguisher, and the fire personel on duty took 5min to cool down this tiny 9.5in steel rotor. Every time they'd stop spraying the pad would ignite...that is hot!

Matt

**DONOTDELETE**
08-16-2002, 08:46 AM
Wow, about that pad igniting thing, what kind of pads were u using? I know that street pads can overheat, but I thought that in a nice brake setup with race pads, heat in the brake system was mainly a prolbem only with the rotors and brake fluid.

ruf4play
08-16-2002, 09:59 AM
That sounds like inadequate air ducting. You need to get more air to those things. One other thing to check is your front wheel bearings. With a stock steel one-piece rotor, all of that heat is transferred into the hub as well and can cause the bearing to break down. That's one of the main reasons to go to two-piece rotors with an aluminum hat (conducts less heat). They will also have a lot better venting and heat expansion characteristics. Are they allowed in your series? What pads are you using?

S14GTR
08-16-2002, 10:34 AM
If it's bad to cool the brake with air duct, then why would a Ferrari 550 Maranelo would have this from the factory....

jimc-s13
08-16-2002, 07:32 PM
I've never heard that brake ducts could be too large or flow too much air, unless they were keeping the brakes too cold. Every race car I've seen, including cars such as the Audi prototypes, run huge brake ducts. Some cars (such as TransAm and NASCAR) run water injection in their brake ducts for extra cooling.

I can't believe a "brake engineer" would tell you that less cooling is better, especially if you're setting pads on fire!

Jim
had rotors "blue'd" from heat all the way to the mounting face, needs bigger brake ducts!

Ps. Is StopTech the ones making the strange brakes with the brake pad that covers the whole rotor?

mattmartindrift
08-16-2002, 10:59 PM
well for one our race series in which my team runs Grand-Am cup. And if you asked b4 recomending things...you cannot run ducts over 3", and Factory brakes must be used, we had TRD homologize a special stoptec edition brake set but it was rejected by tech. And a Ferrari 575M has brakes ducts because they carefully researched proper ducting size, angles, and flow extensively, and they have the right combination due to Ferrari's R&amp;D

Matt

mattmartindrift
08-16-2002, 11:02 PM
I'm not sure about the pad covering the whole rotor, but as for the pads igniting we are researching lotsa different pad options, and we have fairly heavy cars, so the brakes get quite hot, we are also trying to tune in the brake bias adjusters for adequate operating ranges

Matt

fsae_alum
08-17-2002, 09:31 AM
OK yes, there is an optimal brake pad temperature. To a good degree, the time it takes for the brake pad to get to it's optimal temperature depends on the pad compound and the rotor compound (i.e. Carbon, MMC, Aluminum with copper coating). As for the cooling ducts, yes they are needed on some cars and not on others. It depends on the operating temperature of the disc and pad combination. If the pad is experiencing a temperature above it's optimal operating range, they a cooling duct is needed. If it is below the operating range, a new pad needs to be looked at. Ducting can play a critical role in brake performance, but only if the brake is exceeding it's optimal operating temperature. This knowledge comes from extensive experience working on 6 open wheeled racing cars.

**DONOTDELETE**
08-17-2002, 11:03 AM
</font><blockquote><font class="small[/img]In reply to:</font><hr />
Ps. Is StopTech the ones making the strange brakes with the brake pad that covers the whole rotor?


[/QUOTE] The company thats devloping the full contact disc brake is a company from Quebec ( Canada ) called NewTech (http://www.newtech-ibs.com/) the brake is almost ready for the use on production cars....
Maby this can be a solution to your brake problem check out their site It contains a lot on info and grafs on how it works....

mattmartindrift
08-17-2002, 04:05 PM
as I said our race series requires Factory brake systems used on the cars, so we can only work w/ pads, biasing, valving, and cooling

Matt