Paulie964

I am back looking for your guys' excellent wisdom once again ...

Right now, my car is sitting on drilled Zimmerman rotors. These have seen a couple of track days, and a few miles before that. They are not cracked, have zero lip, but do seem a bit shiny (no hot spots) and have ever so slight grooving.

I have already ordered new rotors (Sebro), but I am finding conflicting opinions here. Some say, pending there is enough meat left, just resurface, others are saying, drilled is a no go for track use. So now i'm not sure what to do here ...

Additionally, I am installing the 4 piston calipers in the rear, taking out the p/v, and installing Cool Carbon Pads (thought i would give them a shot), speaking of which; are the front and rear pads the same now? (with the installation of the 4 piston calipers)

FeralComprehension

Personally at my skill level I'd want to get as much life from the rotors as possible so I'd just run the ones on the car until they actually demanded replacement. If you're a real hot shoe and need 100% brakes then mebbe you'd choose differently.

My '90C4 uses the same pads front and back.

Gus

Just a couple of track days - I would say they are about broken in - why replace
If you have questions mic the thickness and see how much wear you have left - my guess is it will pretty close to being like new- - front and rear pads should not be the same - but I don't know what calipers you are running -
If you must change rotors then think of switching to the turbo rotors

boxsey911

Yes, once you change to the 4 pots at the back and assuming you have the standard 964 4 pots on the front, the pad pattern in same for both calipers. As an alternative, Hawk blues are fantastic pads for track work but you have to be wary that they produce a lot of dust that can make a mess of your wheels.

Turn3 Autosport

Drilled rotors are fine for track. Yes, eventually they will crack but they will likely be at, or near, their wear limit when they do.

With the 4 piston rears the pads will be the same front to rear.

A good dual use pad is hard to find. For DE/Track we are fond of Pagid and we keep them in inventory.

Cheers

Makmov

Depends on the heat cycles, the cracks are heat cracks and I haven't seen a catastrophic failure for those types of cracks. It depends alot of the driver and what kind of braker they are. I have seen rotors crack right away with plenty of service life in them. They could very well be enough meat there just to resuface them. As far as drilled, there is nothing wrong with drilled other than they are probably overkill for your application, and they like to heat crack. You porbably just want or need gas slotted. Pagid I hear are good, but I like Hawk Perfomance.

Paulie964

Thank guys, much appreciated. I think I'll just return the rotors. And yes, they are indeed the later 964 4 pod calipers. I'm not expecting huge change in braking ability, but I do hope to see a little improvement.

Marc Shaw

I just replaced my drilled rear rotors after 2 years (> 30 track days) due to cracks joining and/or cracks > 5 mm. I replaced with DBA slotted but the drilled were fine for years.

Marc

Paulie964

good enough for me!

Turn3 Autosport

There is a lot of BS and such floating around the internet and the paddock of your local DE. Not withstanding poor quality rotors, drilled are fine. Remember that when you buy a new GT3Cup from Porsche it ships with drilled rotors, and that car is not specc'd for bling.....

That said, if replacements are avialable that are slotted instead, I would go that route, but drilled rotors are not what some on the internet would have you believe.