Turbodan

I believe for DE tech inspection no cracks from hole to hole and no cracks to either inner nor outer edge, is the criteria to pass tech. So you could keep an eye on them or replace soon...easy job to replace btw.
and you don't need to remove wheels to clean them (depending on what wheels you run) just turn the wheels and either blow air or water through them. not sure cleaning makes them last much longer but would be slightly cooler.

cre8fun

I don't skim on safety items.

If you decide to run another event on them and your plan is to check them out between sessions, how are you going to see what's going on on the inside face? I've watched brake pad wear between sessions only to be surprised by how much more the inner pad was worn when I finally decided to pull them. if you get a significant crack on the inner face, I doubt you'll see it between sessions and how much do you really save? I used to buy used tires till one blew on the back straight at the Glen. I buy new sets now. was not worth it.

misterwaterfall

This brings up a good question: what is the best way to tell when your rotors are done? Just the size of the cracks? Take a measurement and compare to new?

Kris Murphy

Those rotors would pass tech inspection (I'm the safety chair from my region). Depending if you prefer to do work at the track or at home would determine on when I would replace them. If you don't like to, or cannot do work at the track, I would replace them before going for a three day weekend. If you can do it at the track, I would run them until the cracks connect the dots or hit an outer edge.

At the point they are now, depending on the track, what pads you are running and how aggressive you drive, you could have 1 session left, of 2-3 weekends left.

Quadcammer

+1

the_vetman

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Yup, plenty of life.

lorenzep

I run them till the crack reaches the outer edge. I've never had that actually happen on the track. In my experience, I think they crack when cooling down and you'll have a tell-tale whop, whop, whop from the rotor. Unfortunately I discover the cracks when it's time to go back out. I watch them close when they are at this stage to try not to miss a session. I took removed the drilled rotors and replaced them with slotted sebros and plain centric blanks ($36 each!). I'd always been discouraged to use drilled rotors.

Peter
07 911 turbo

JRitt@essex

Two years ago I wrote an article for our Essex Blog titled, "When is it Time to Replace my Iron Brake Discs?". It was geared specifically towards the AP Racing discs we offer, but it has some good tips and general rules of thumb that are applicable to any discs. Hopefully you find it helpful:

https://www.essexparts.com/news-blog...-my-iron-discs

mark kibort

i agree, but a better analogy would be running a rotor with cracks to the outside compared to running a corded tire. little rotor spider cracks are more like running a tire on the wear bars, or with the tread gone.

mark kibort

rotors are done when the surface is uneven, grooves, and cracks. as well as overall thickness. this is mainly related to the rotor when fitted to another set of pads. the cracks are a structural concern. we all agree, when the holes have cracks that join and/or cracks leading to the edge, you dump them. however badly grooved rotors are good only until the pads are gone, as its hard to get new pads to bed properly with grooved rotors.... so, they are safe as they are, but change them before you replace the pads. lastly, thickness... under the 30mm limit for 32mm thick rotors is a reason to dump them

BK77

Easiest to just replace them now, why try to squeeze 1 or 2 more track days in when you know you have to replace them soon anyway. I'm not sure how confident you can be driving a car with questionable brakes, seems like a carless move to me. Also don't forget about the other guys on the track with you, its not just your safety that's at stake.

mark kibort

there is a good reason to wait.. you should toss the pads when you do change from these rotors.. they are good for another weekend for sure, kill off the pads and start with a new set of rotors and pads.

daylorb

What do you save by getting one extra day out of these vs. using new rotors? Not a whole lot... measured in a few dollars. Seems like a completely unnecessary risk.

mark kibort

the rotors in question are not that bad.. its normal to have cracking at the holes pretty quickly.. it's not a day, its probably about 2-3 more days and if the pads are half gone, it's the pads your tossing out too. so, its like a $200 dollar waste. there is nothing wrong with those rotors. keep an eye on them and when the cracks grow, make the call then. now, if the pads were toast, i would likely put on a new set of rotors and pads. i certainly wouldnt put a new set of pads on them, unless i was expecting 3 more weekends on them. (assuming you wear out pads every 4 weekends and rotors every season)

awrryan