Overheated brakes?, Ever actually done this? Options

[lapuwali]

With all of the recent caliper discussions, I got to thinking: has anyone here actually suffered from stock rotors overheating? Street or track? Which calipers? Which MC?

I've personally only ever suffered from brake fade caused by overheating brakes twice, and neither time was in a 914. Once on a Alfa with inboard rear brakes and an overenthusiatic romp along a road with lots of downhill hairpins, the other time on a Mini with drums all round, also on a romp through a (different) set of downhill hairpins. The Alfa was heavy and suffered from bad cooling of those inboard brakes (which had vented rotors), and the Mini just used cheap iron drums (and I was deliberately trying to induce fade). Interestingly, another very similar Alfa that was much lighter (400lbs or so, from lighter body stampings and a four instead of a six) never suffered from fade despite solid rotors at both ends, on the same roads that would cook the brakes on the later, heavier car.

Much as I approve of the idea of good strong brakes, I wonder just how necessary big, heavy, expensive vented rotors really are on the car (at least with stock or near-stock power).

[airsix]

QUOTE (lapuwali @ Feb 24 2005, 10:44 AM)

With all of the recent caliper discussions, I got to thinking: has anyone here actually suffered from stock rotors overheating? Street or track? Which calipers? Which MC?

I've experienced brake fade with stock 914 brakes on both street and track. These were completely stock brakes with good pads, fresh fluid, and freshly bled.
On the track I was running an autocross with a 1.4 mile course with multiple 70mph sections. There were three sections of accelerating to about 70 followed by braking to about 5-10mph one right after another literally back to back. At the end of the third-in-a-row braking section there was very noticable fade.
On the street I was trying to chase down a 911RS (turned out to be a clone). Braking from about 110mph for a 20mph left turn the brakes went away at about 35mph. To this day my seat cussion is still gripped tightly between my buttox.
Both occassions were on very hot days (close to 100 F) and driving on very sticky tires. Right before the brakes went while chasing that 911 I remember feeling smug at my braking prowess because the fronts were starting to chirp and smoke, but were not locked - it was the perfect threshhold braking, and then suddenly there were no brakes, I had both feet on the pedal and I was flying into a corner 40% faster than I had intended. I kept it out of the ditch and went on to install 19mm MC, Tilton bias valve, and vented 911 A's on all four corners. I've tried repeated at-the-limit braking from 120mph* to see if they will fade and they don't.

-Ben M.

*post-turbo