Jason, what are you basing your experience on? Drilling the solid rotors seems like it would help (if I take them off I might as well switch over to vented rotors though) but I know of atleast 2 Milanos that were fading their brakes this last weekend at the track in very hot weather with stock proportioning valves, track biased pads, and DOT 4 fluid (or better?).
We have done a couple rear drilled and slotted rotors with some success and with basic knowledge of braking it could be effective. If the rotors are prone to fade on the rear, then drilling them to reduce the heat should be effective, of course installing vented would be the best option in my book. Or larger front rotors can calipers.
Without a real brake upgrade they will over heat and fade, they are not going to be able to handle much at stock level especially if they are just throwing race pads in and fluid.
The front rotors are only 22mm thick/269mm in diameter rears are 9.8mm thick/250mm in diameter. That is the weak point. I would say at least 26-32mm thick/289-315mm in diameter would reduce this problem. Brake booster and MC seem to be a pretty good size to handle the larger and thicker rotors.
I just did a big brake upgrade on my 164 for example (12V) version.
Rear brakes not a real problem but the fronts are not the best.
They are also 22m thick/281mm in diameter.
I opted to upgrade the whole brake system from a 24V LS, Calipers, carriers, rotors, brake booster and MC.
Still the same size rotors in diameter but 26mm thick. Brake calipers went from a 54mm piston to a 57mm piston, Brake booster went from 6" in length to 16" in length with a more potent MC. Rears happen to be the same on all cars so no change there.
Drastic drastic difference in braking power. The thickness of the rotor handles the heat better while the other components work together to provide better bite or pressure.
I know this is not a great example but it gets my point across I hope?
I think the front to rear rotors are too close in diameter and that a larger front rotor and caliper would probably cure the problem.
I hope that makes sense?
Could also be tire wheels combo as well.
To properly design the right system:
1.Weigh the four corners of the car
2. Design the front and rear brake components to deliver torque in the same ratio as the front-to-rear weight distribution
Modifying your car for the street or for the track, be aware that changes in the braking system as well as changes in the car’s ride height, weight distribution, or physical dimensions can swing brake bias all over the place.
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Factors that will increase front bias------------
Factors that will increase rear bias
Increased front rotor diameter------------------Increased rear rotor diameter
Increased front brake pad coefficient of friction----Increased rear brake pad coefficient of friction
Increased front caliper piston diameter(s)---Increased rear caliper piston diameter(s)
Decreased rear rotor diameter------------------Decreased front rotor diameter
Decreased rear brake pad coefficient of friction----Decreased front brake pad coefficient of friction
Decreased rear caliper piston diameter(s)----Decreased front caliper piston diameter(s)
Lower center of gravity----------------------Higher center of gravity
More weight on rear axle--------------------Less weight on rear axle
Less weight on front axle--------------------More weight on front axle
Less sticky tires (lower deceleration limit)--------More sticky tires (higher deceleration limit)
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As far as fluid is concerned Once the fluid over heats it is done, so the fade they experienced may be caused but 1 overheating as you mention and 2 the fluid overheating past it's boiling point then rendered useless thus promoting fade under extreme conditions. Improper race pad and rotor break in would cause this issues as well. If they are not seated correctly for race purposes they can experience lots of fade under extreme conditions.
Fluid I always recommend is ATE super Blue or ATE gold, same thing just ones blue and the other, well it's gold.
There could be many many issues contributing to the fading. Pads and fluids won't cure a improper brake system and improper brake in process for race pads.
You can get good results from the stock system if they are seated correctly.
Try turning the rotors and braking in the rotors correctly for maximum performance.
Just my advice.
Jason