Kruel,

The temperature was pretty consistent from 52 early morning to 70 at peak. It became cloudy and north winds picked around noon. Showers were present on the last run. On the asphalt, it gane about 30F from 45 to 74f at peak.

On the braking note, i was in the advance group, with no passing regulations (besided basic pointing). These guys are pretty good (track junkies), so i didn't lose or gain any noticeable time when being passed or me passing them. Whatever the traffic, i ran between 2.02 t0 2.13 each laps (actually i spoung out on an ran a 3.05 on 1 occasion in the afternoon).

Cheers,
Phil

Sphon,
The highest i got on my left side was 532F. This is after half a track warn down lap + pit lane entry time + me stopping at entrance to park + me running to my box to get the laser reader. This equals to about 120-140 seconds after the last serious braking zone.
On the other side, my laser temp reader couldn't read my friend M3 since it was maxed out at 608F... Don't forget that i: parked, ran, recorded my temps way before it took a reading of his rotors... I can't even imagine the initial heat these things had to sustain.
Notes on the 2010 BMW temps:
- car is new and has less than 8k miles;
- owner: is a national karting competiter.
Cheers,
Phil

Stock pad, probably 800-1000F, higher for race pads. You have to worry about fluid boiling too.

nice OP...


You'll get alot of flak for this DIY for not giving adequate air. It's better than none at all even if it's blasting against the rotors and not focused on the rotor.

Still props for doing it bro.....

Cossie, any idea on high temps for the stock rotor?

Philipp- thanks for the data! +rep :tup:

i was quite surprised to see the temps rise on blocked. (most likely not) but almost seemed like it was forcing engine heat into the wells or something. :confused:

regardless thanks again for the experiment and results. :tup:

Kenchan,
I was also very surprised about this finding results:ugh2:. Not sure if the methodology was "science proof" but the end results weren't convincing...
Because of all the issues surrounding brake's overheating, i really can't wait for an effective solution!
cheers
Phil

Hey, I was the creator of the DIY Brake Cooling Ducts post. Great job of scientifically testing your mod at the track. I never took the opportunity to test mine but at least I know that my ducts completely solved my ice mode problem at the track. When I saw your post I thought it should work to at least lower temps a little.

I suspect the problem with your mod was that the air entering the inlet cannot overcome the extremely high pressure air coming off the tires. But if you can route that inlet air into the center of the wheel it bypasses that high pressure area.

Planning to work on mine soon. I don't remember looking at our dust shields before (should have looked when I had the rotors off for the extended wheel bolts), but I would imagine we have them, and they block air intake to the center of the rotor to some degree. So I was planning to cut into the dust shields and mount a flange there, like Modshack's Audi pictures here: http://www.the370z.com/diy-section-d...tml#post101626.

I'm thinking I'll probably have a friend with some metal working equipment (proper cutters, a plasma cutter if necc) help with cutting the right-sized hole in the dust shield, and then just rivet a flange into there, aiming for as close to the center as possible (at least, far enough in that the air is mostly being drawn through the center of the rotor rather than dumping on the back surface of it). I'll try to get some pics when we get to this.

nada. unlike most people here, brake cooling is the least of my concern as i have tracked cars that are faster with smaller brakes. they all seem to stop fine with the one exception to the 350. for a 20 minute hpde session, i am not sure how much the ducts help. i look at it as one of those things that help, but not really big enough for me to worry about. you are better off spending money on better pads, better brake fluid and cryo treat your rotors. this is a bigger problem for guys who race their cars side by side.......

The dust shield blocks air to the hub pretty significantly. Cutting a hole in the dust shield shouldn't be too difficult, I think I'll just use the dremel. For now I think I'm just going to strip the fender liner all together, run a 3" duct with 2" reducer and come up with a way to direct the air through the gap between the caliper and the hub (probably use a 2" metal coupling and beat on one end with a hammer). Unfortunately with the AP Racing caliper bracket to offset the caliper the gap is even tighter. You also have to deal with the fact that everything moves when you turn the wheel.

Not sure if I'll get this done by my next track day on Memorial day, but we'll see. It's a short track with 3 heavy braking zones and not a lot of time for cooling. Either way I'll have rotor temp paint and caliper temperature gauges installed. I'll be using 1800F MOT Sintered track pads.

Cossie,
Already went into that route. I was running on StopTechs on all corners with Castrol LMA.
Phil

I've thought of removing the fender liner also. Just to get one more thing out of the way. But I worried about all the dirt getting thrown around in there for it exposes the headlights and opens up more area to the engine bay.

Sorry for getting off topic.

Also consider wheel design for your track wheels. Good wheel design can help with rotor cooling as well.

I have another idea for cooling I'm working on that I will share soon

try Castrol SRF, much better fluid