invisableflames

I finished my car in time to make it to the track day at Road America yesterday. I had a great time but my day was cut short. We ran 5, 20 minute sessions and when pulling off from session 4 the track safety personnel pulled my car over to the side when exiting and said i multiple corner workers reported brake fire on my car. They checked it over and didn't seem to find anything. I thought it was weird cause my brake were working better then they had all day. When back at the paddock i check everything over and it looked good. I have the cobra brake upgrade and 3 inch brake ducting. On session 5 the last lap i went into corner 5 and the brakes were great up till the last second, they just dropped to the floor and it was too late, i steered into the gravel pit. the safety workers came over again and said i was on fire again. they pulled me out and i drove back to the paddocks. broke my radiator support, scratched the side skirt to hell, rippled the fender, and bent something, one tire was toe in and one is toe out. anyways, i would like to know if anyone else has had problems with brake fires. It was too bad, we packed up early, we were suppose to run another 5 sessions today but I also shredded a tire on the fender. That and the brake problems.

67mustang302

My guess is you were working the brakes so hard the rotors were glowing. Or perhaps the pads were smoking or even bruning. What pads are you running? If you're going to run a full bodied V8 car on a road course you REALLY need to be using brakes that are actually designed for that.

PNYXPRESS

His calipers/rotors are probably correct for the application. Sounds like the rotors were glowing and you boiled the fluid which caused your brakes to fail. Try using wilwoods EXP600 plus fluid, its expensive but wont boil over as easily.
http://www.wilwood.com/BrakeFluid/BrakeFluid.aspx

67mustang302

Fluid boil and/or pad failure would cause the brakes to fail. If the pedal did drop all the way to the floor then it likely was fluid boil. But the "brake fire" the track officials saw wasn't fluid boil, so something else is going on. My guess is wrong brake fluid and wrong pad compound.

invisableflames

I am running MOTUL 600 fluid and Hawk HPS pads all around. I know it would be better to run a race pad but they did well for the first 3 runs. I checked them after each run and there is still a good amount of material left. I am kind of upset they didn't black flag me for the brake fire as this may not of happened if they did. Idk, I am thinking about getting brake duct fans and maybe going even bigger with the calipers. We will see. I was happy with my brake other then this. I seen two other cars one with brembos and one with wilwoods that had trouble with rotors cracking. i made sure to inspect mine after each session and they held up. Does anyone know what actually causes a brake fire? is it just the rotor getting so hot it starts to flame. I thought it might be the brake dust buildup, so i cleaned everything off before session 5 but obviously it didn't help. The only other thing i could think of is it may have been fluid escaping and catching fire, but i really don't know.

67mustang302

Cracked rotors are most commonly a result of using the fagtastic cross drilled crap. Don't do that. Second most common cause is failure to properly bed pads and rotors. Do yourself a favor and run a good pad, Wilwood makes some pads that are dual purpose street/asphalt RR pads(I run their E pad on my 67). Also make sure to flush fluid regularly if you race it like that, and don't let it go for a while, the boiling point drops as it absorbs water over time. As for fires, it can be dust that burns or oils that kick up from the road etc. Typically a true brake fire is from burning the crap out of the brakes until seals fail around pistons, and the fluid catches fire.

Ducting isn't your problem. Wilwood has pads you can run on your car that wouldn't need any ducting and wouldn't fade out or burn up. Your car simply isn't fast enough to NEED ducting....and if you do need it that's a sign your pads aren't up to the task.

Do yourself several favors. Flush the fluid...inspect your brakes for signs of thermal cracking, glazed pads, leaks etc. And get a real pad.

invisableflames

Are you sure about the whole my car is not fast enough to need ducting thing? I was reaching 145-155 consistently. I felt i was getting out brake'd be most others, i could not throw the car into a corner like most of the others in my class. They would go much deeper in the corner then brake, most of the time i was braking before they did and i was behind them, and still came in a bit hot for the corner. I changed the fluid before the race, and the rotors were bedded well. beside not having a race pad i dont think i could have dont anything else. would a race pad really help that much or do i need a bigger set of brakes?

PNYXPRESS

Race pads will def help you. Is this a dedicated track car or street/track car, cause most good race pads suck ***** on the street as they arent able to get up to temp with normal driving.

67mustang302

Ducting keeps brakes cool. Pads that really grip are designed to operate hotter. My Wilwood E pads make peak brake friction at around 600-700 F iirc. And work all the way out to 1,000 F. Have you ever seen a rotor at 1,000* F? They glow very brightly. And those are just dual purpose pads. Full on race pads(like was said suck on the street cuz they're cold) operate to temps past 1,200-1,300* F.

The problem with the "high performance" street pads, is they're not really intended for serious racing, and it's unlikely you could get enough cooling via ducting to keep them from burning up. A dual purpose street/track pad won't even need ducting in most cases, since a street car doesn't really go fast enough frequently enough to get that terribly hot. That and they provide much better friction and braking control. You'd need a serious car that runs at speeds over 160mph in multiple parts of the track to NEED ducting with a pad designed for the track.

You should at least try a dual purpose pad from Wilwood and see how it does, with or without ducting. If you REALLY want to go all out, then swap to full race pads at the track and run on them. Pads designed to operate under high heat like that are phenomenally better than basic high performance pads.

Also I doubt that you were really getting up to an honest 155mph in a full bodied street car. It's likely that your speedo is miscalibrated, since most factory speedos read high anyway(sometimes by as much as 10%). That and changing tires will effect it as well.

invisableflames

If i run a track pad do i need to bed a set of rotors in specifically for the track pads? I guess what i am asking is if i run street pads on the street and then switch to a track pad at the track should switch to a set of rotors only run with track pads or can my street pad rotors be used with the track pads without problems?