Easy there tiger, don't take my word for it - read Steve@Rennsports comments on turning rotors:
https://rennlist.com/forums/911-forum/977018-turn-rotors-on-911-a.html
http://forums.pelicanparts.com/porsche-911-technical-forum/397161-brake-disc-question.html
http://forums.pelicanparts.com/porsche-911-technical-forum/491316-930-brake-rotors-thickness.html

I'm certainly not advocating wasting money - my point is that there are things you don't skimp on -brakes and steering being at the top of my list, and that there are other marques that are more economical to maintain.

"I NEVER machine/turn rotors on a car unless they are 322mm or larger and will never be used on a race track."
Not sure what he's talking about. Stock thickness is 24 mm. Minimum is 22mm. I'm still above minimum even with the turning that was done. There's a reason they list a minimum thickness. Having brake rotors turned isn't really "skimping" IMO. I have had the rotors turned of almost every vehicle I have owned including an F350 that was used almost strictly for pulling a 3900lb trailer with machines weighing over 8000lbs. I have never suffered a failure due to turned rotors. I have OTOH suffered problems related to stuck caliper pistons and a brake line rupture. So if I were to call something "skimping" I'd have to say it's rebuilding calipers or driving around on old brake lines.

He means 322 mm in diameter, not thickness. And calipers are meant to be rebuilt, hence the availability of replacement pistons and seals. Rotors are a known disposable part.

Is that why there's a minimum thickness rating for rotors? Because they're supposed to be thrown away? Think about what you're saying before you say it.

Don't get me wrong here. I'm simply going to end the myth here that rotors are supposed to be tossed. It's a silly notion that is based on no real fact. If all four brakes are working properly, there's no reason you shouldn't turn rotors unless their is noticeable bluing of the rotor meaning they have gotten WAY too hot. Then, yes, you get rid of them because they have lost some of the tempering. Otherwise, turning a rotor does not make them any less safe or places like Oreilly's wouldn't do it nor would the shop that did mine.

If you had purchased new rotors, I bet you would have won next time. :D

I never thought of it that way. Maybe I'm dealing with a far more sophisticated group of judges than I was thinking.
On second thought though, I know most of the judges so... no, not really. The worst part is, I was a judge one year and STILL lost. :eek:

Cab,

When I first read the thread, I was solidly in the "just buy new ones camp." Now, you won me over, I think since rotors have become so cheap, most of us just replace, or we've run them so long that they couldn't be turned safe.

On the other hand is my DD Toyota which are probably cheaper to buy new than get turned and since I park it outside, they usually have a "nice" rust crust on the outer edge.

One less thing in the landfill, well they do get recycled, but that takes energy too.

Best,
Rutager

There is a minimum thickness because when the rotor reaches that minimum, it is designed to be discarded. It's not a myth at all. If they are too thin, you THROW THEM. Not sure if you are arguing that fact.

Yours aren't too thin, however. They just aren't working the way you want them to.

Finally, back when Porsche made the rotors for your car, they were the only ones making them. If you wanted a replacement, they were probably $500 each from the dealer. Now, there are aftermarket rotors that cost next to nothing.

What year is your car?

Pelican has rotors for a 1983 for example, that are TWENTY TWO DOLLARS. That's right, 22 bucks for a rotor.

Pelican Parts - European Automotive Parts and Accessories - Porsche • BMW • Mercedes • Volkswagen • Audi • Saab • Volvo • MINI

Why would you ever fcuk around with turning them when they can be had for 22 bucks?

Just the bandwidth you wasted on this thread is worth 22 bucks alone.

This is not true at Porsche. Gotta be at min thickness to replace or it can come back on the service dept in the way of bad review or unprofessionalism. Now if the customer wants replacement that's their prerogative. In my experience with OE Porsche brake components there is rarely ever a pulsation issue even after rotors are a way past min thickness.

One thing is certain here. The amount of time you have spent arguing whether rotors should be turned or not on a thread that wasn't asking IF they should be turned but rather whether others had difficulty finding somewhere to turn them has been wasted.
Please... don't hesitate to move along now and stop wasting your time.

Amen...

As long as your rotors are in spec and don't show any signs of drastic overheating or in the case of some cheaper made in China rotors you have rusting from the inside out, I wouldn't hesitate to get a set turned. The most important part is figuring out why the buildup or overheating occurred. I know in my case it happened a few years ago when I first got the car on the road and didn't take the time to really inspect the overall braking system other than to replace the fluid. I later found a few of my calipers had stuck pistons.

One more side thread for brake geeks
I asked if people thought the direction of rotor air scoops (in the middle of the rotor) mattered about a week ago on Cayenne forum (Early Cayenne Turbo's are HEAVY cars, big brakes) and I got a ton of opinions and learned more than I though I would.
https://rennlist.com/forums/porsche-cayenne-forum/1005857-rotors-does-l-r-side-really-matter.html

There is no "opinion" on this subject. Different part numbers left and right. The engineers at Porsche got this right.