[N0tt0N]

After we ran out of brake pad at the First DE it was time to reassess the entire solution. I love the bite of the PFC08s but since it is the only pad I have experience with since OE and based on the feedback here I decided I would try some Pagid Yellows all around. Time to throw the Blechster up on the lift!


Beer then Liquor... or is it Lick Her than Beer... I have received several conflicting opinions but had settled on PFCs are good over everything with no break in but Pagids need virgins (preferable already had by another Pagid of the same color which seems like an bigoted oxymoron). So, I resolved to change both pads and rotors.

I currently run Girodisc floating rotors with PFC08s. Prior to that I ran OE rotors with PFC08s (reduced them nicely from thick to thin) which was easy. Only ran OE rotors and pads for one event before popping in the PFC08s.

It turns out not only the pads ran out at the last event. The fronts finally cracked all the way to the edge, perhaps because the PFC08s really escalate the temps as they pass 50%.


The rears were OK but there was a strange ridge forming where the PFC08s usually start to crumble when they get past half way.


Out they go, everything in the trash! But first, you need to disassemble the rotors from the hats. Not sure if is worth the effort rather than just chucking OE rotors and slapping on a new set. Anyway here's what they look like after being ridden hard and put up wet. Some secret stash of klag!


Using a 5mm hex, simply loosen each of the ten cap head screws and throw them and their washers and other flotsam and jetsam in the garbage. As you loosen each screw, give it an easy tap back down and that will drive out the rivnut style backer out of the hat (the pretty center part). Throw them in the trash. It seems like a waste but you have to use a new set each time you replace the rotor. They've seen active duty stopping 3000# of high speed, low drag Porsche so don't be stingy and save them. Even if they are race-proven and have seen many podiums.

Once they are separated spend many hours with a scotch pad and soap cleaning the hats before switching to solvent before giving up and going to bed. Slap on the wheels before retiring for the night for a bad-ass, drifter looking setup.


In the morning after a night of frisky regrets, get out the 220 grit sandpaper you scoffed at the day before and remove: a) the ferrous oxide crap that is embedded in the hat and b) the aluminum oxide crap that has resulted from the happy electro-chemical interaction of aluminum sandwiched between cast iron spindles and steel rotors and alloy wheels. A metallurgic gang-bang. The iron rust sands off red and clogs the sandpaper. The aluminum "rust" sands off black and clogs the sandpaper. You can't get all the discoloration off so just sand until it is flat and you can't feel it so much. The hat on top is post sand paper capitol punishment. The lower one is touchy feely "we're all good inside" treatment.


Time to assemble the coddled hats with the new, pristine rotors. Shiny parts are happy parts! There are two types of fastener combinations. One is a shorter screw with a darker colored Bellville washer. The other is a longer screw with a square spacer, a thin metal spring-like thing, and a washer. They come preassembled so you can't really mess it up as long as you remove the rivnut and leave the screws and their appendages together. The rivnuts snap in readily into the hat and through the rotors. I only had to tap two in with a light brass hammerlet. With the nuts seated flip the hat/rotor over. Some nuts may fall out, no worries. I suggest starting with the simpler screw and Belleville washer. Apply some high-temp red Loctite to the screw with the washer already on it. Holding the nut from underneath (so it doesn't fall out) screw in the screw from above and use a spinner with the 5mm hex socket on it spin it in hand tight. Skip over four spaces and repeat until you run out of the five simple screw/washer combos. Do the same with the five square-spacer, thin flat spring, washer, screw combos for the remaining spots to complete the initial assembly. Then, following the same sequence to ensure even torqueing, apply 60 in/lbs with a torque wrench. Its not a lot of torque. One assembly done!


Note: Make sure to put the big rotors on the small hats for the fronts and the small rotors on the big hats for the rears. Its the law of Conservation of Brakes. The big hats have room inside for the emergency brake and go in the rear where there is less need for brakes. The small hats are for the front where there are no emergency brakes inside and they need massive amounts of brake.

Foreshadowing Note: Both assemblies will mount on either hub. While mounting the tiny rear rotors on the front will result in about 50% less pad wear (because the pads are off the rotors), and on initial thought would therefore be excellent for long runs like LeMans, don't do it. You will figure this out at some point. Hopefully while trying to put the fronts on the rear where they will not fit but should you get them to fit you will find out at Turn 1 why it is not a good idea.

Repeat three times. You may consider like I did to swap the hats from left to right since around here the left hats see more heat then the right (clock-wise courses). The hats are swappable but the rotors are directional with the slots saying, "Grrrrrrr!" rather than "Oh Thtop it!". Assemblies on right are for the left. Assemblies on the left are not. (Thanks for the correction, Jim!)


Install per the Usual. Stuff in chubby Pagid Yellows. Have random strange strangers stop their cars and take pictures. This is not correct and is actually a left rotor mounted on the right! Fixing. Sigh.


Drop it like its hot, stow the lift, and hoser down. Like Steve Miller says, "Everything's Better When Wet!"


Hire a Fluffer for the CIs so you can get to Red.

[trytryagain]

Thanks for the mini tutorial! Timely for me as it will not be long before I need to go through this same process.

However, based on the slot orientations it seems like the rotors on the left of your finished photo would go on the right side of the car? At least that's how mine are oriented. When I installed my new rotors I tried to take the piece out of the box marked "right" and put it on the right side of the car. Maybe they were just messing with me though.

So I went out to the garage and found the instructions. Sorry for the sideways view:

[N0tt0N]

Well spank my butt. Looks like you are absolutely correct. GRRRR it is. Looks like another day of moving stuff.

Note to HR: Fire that Tech writer for choosing to show only the left rotor and therefore showing it rotating counter clockwise.

I will swap them back and fix the original post lest a reader be mislead. Thanks!

[trytryagain]

I agree that there is something that looks wrong about the GRRR orientation, which was why I scrutinized it closely when putting my rotors on.

Interestingly, on my Mom's Mercedes AMG luxo-rocket, the slotted rotors on the left and right are identical. Like they installed two left hand rotors at the factory! Quality control NOT!

[Vicegrip]

Some slotted rotors are not right / left. From what I have read it matters little which way the slots "point" With vented rotors that have curved internal fins it does matter which way the fins spin.

[Trak Ratt]

Originally Posted by N0tt0N

....
Note to HR: Fire that Tech writer for choosing to show only the left rotor and therefore showing it rotating counter clockwise.

If you pay him by the word then it was prolly a trap!!

Nice right up and thanks for the personal highlights too

I see the house across the street is 4sale.....

[Chopper Dropper]

Have heard same as VG, slot direction does not matter.

[spiffyjiff]

great write up! I have a toasted front set that i have been too lazy to swap out the discs (ended up simply buying OEM to carry me thru a couple events). but this gives me hope, maybe i'll try it!

sorry if i missed, but where did you get the new discs?

[N0tt0N]

Originally Posted by spiffyjiff

great write up! I have a toasted front set that i have been too lazy to swap out the discs (ended up simply buying OEM to carry me thru a couple events). but this gives me hope, maybe i'll try it!

sorry if i missed, but where did you get the new discs?

I purchased them straight from Girodisc. BTW, since you have them off the car Girodisc will actually assemble them for you if you send them the hats. You just have to disassemble them and ship them in. This is a great service if you are not mechanically inclined but also because they will replace the hats for free if they find them out of spec! I purchased a used set originally and sent the old hats in. New ones returned! Alas, I would have to leave the car up on blocks and so did not take advantage of that excellent option.

[TurboPooch]

I agree that slot direction does not matter. It's just a degassing feature from what I understand. But what is important is which way do the vanes move air. Typically there is some kind of brake ducting whether it be tubes or scoops which funnel air from the inside to the outside of the hub/disc/wheel over the inner bearing area. Vanes inside the rotor then help to facilitate this movement of air not work against it so they always need to point "up" to pull air through. Slots don't matter then. But they do look racey and cool and that is important. That's how I remember it anyway....