[SYT_Shadow]

We've had PFC, the BimmerWorld-Alcon and the AP Radical rear

PFC is top shelf. The fattest pads which also happen to be cheapest. We still have one full BBK and a second front-only PFC. It's good enough that we spent a long time in Solidworks and 3D printing to get front brackets built for our F8X as PFC does not officially support the F.
The Z54/45 kit properly sends bias to the rear of the car. 28mm front, 20mm rear pad.
We continue to get this serviced without issues, at least so far. We've been hearing about gloom and doom for years regarding PFC service, so far everything is in stock at BimmerWorld and we're yet to have any kind of issue, whether it's rotors, hats, pads or rebuild kits for the pistons/seals.
The PFC rotors are cast in the US and are cut without using lubricating oil. Massive cost difference but that avoids the rotor from absorbing oil which will bleed out during use.
Front and rear pads come out completely flat with no taper despite being the fattest pads of all.

The Bimmerworld-Alcon kit is the new hotness. We've run it for two seasons. It has a 36mm front rotor (vs 32-34mm PFC/AP) and that makes a huge difference in durability and heat dissipation/thermal stability.
25mm front, 23mm rear. It sends bias to the rear of the car.
A 36mm front rotor cannot be understood properly until you hold one in your hands. It is absolutely insane. So far we have never managed to crack one all the way through. 50% more durability than the PFC rotor which was otherwise the reigning champion.
Excellent pad options as well. The front uses the same pad shape as the AP big kit and has all the newer PFC compounds.
The front and rear rotors always come prebedded, a very nice plus

The AP Radical seems to get a lot of love here. We are not among the fans. They were on the car four events and we quickly tired of pad taper making the rear 17mm pad even less effective than it would be otherwise as well as rotor life that seemed more like a stock brake than a BBK. I heard they redesigned them, but we clearly remember their sales guy telling us all how their rotors were vastly superior to the PFC rotor, then we run them, they last half of a PFC rotor and they eventually get redesigned. I abhor marketing bullshit when it comes to track stuff. The Turner M4 GT4 cars have Girodisc rotor conversions added to the spec AP kit and I'm not one bit surprised.
We still have the two sets of rear pads we ran that are tapered enough to build a triangle when you stack them. When you have a 17mm pad to begin with and then you get 5mm of taper, you're screwed.
The kit was sold after four events and we committed to building a rear PFC adapter, then BimmerWorld launched the Alcons and we went to that instead.


Possible reasons for our lackluster experience with APs:
-We run full weight cars with no aero and punish the brakes more than people running 6 seconds faster that are lightened and have aero. And we do that for an hour at a time as we double-track cars. This is likely the most savage use of a brake kit.
-Not many people here go through one 25-28mm pad in one weekend, but we do. Every weekend. A few times we have gone through one 28-25mm pad in a single day!
-We came from a PFC kit and clearly felt the downgrade with the AP. I'm sure if one comes from stock then APs feel pretty awesome
-My brother and I are both mechanical engineers with grad degrees in engineering as well. We understand the theory behind the cool shape of the Radical, but the results need to be there. They are not. It is clear to us that in the pursuit of a sexy shape they cut out too much material and compromised rigidity. You see this for example where the PFC has three cross-bolts per side but the AP Radical has two: where the third one would go there is a nice cutout to lighten the caliper.



As luck would have it, our two sets of nickel plated BW-Alcons won't be ready until June so... GTS1 has stock calipers with Giro rotors and GTS2 has the PFC front and AP rear. Yes, we bought our old AP kit back and will use it for the first half of the season.