petee_c

I was not aware of the cracking issue until I came onto the interweb...

I am looking to replace my stock rotors soon (not cracked) and came across the cracking issue...

then I read that slotted rotors are suggested, then someone showed me a picture of their fractured slotted rotor...

I can get a set of OEM style rotors for a lot cheaper than the cheapest slotted rotor, and now I'm not sure what to get...

Budget is a factor, and my car will be tracked maybe 5x this season I anticipate 8-10hrs tracktime total, novice driver.

sbelles

What car?

petee_c

sorry 2001 Boxster S - has the rotors from the 996 on the front....

Steve113

If stock is drilled and you can get OEM for a lot let I would buy those see how they hold up. The issue is more the crappy brake manf . I raced on drilled and no issues. By the time the crack spread the rotors were worn out anyway.
Remember fine cracking is no issue it once the crack travel from hole to hole and connect

Hella-Buggin'

Get Sebro Slotted and be done. Same price as OE and you don't have to fret over the cracking.

Scooby921

Except that you still induce a lot of heating and cooling cycles that eventually result in surface fractures and stress cracks, even in solid blanks. The cracking of rotors isn't because of cross-drilled holes. It's because of the frequent expanding and contracting of the material. Slotted or blanks might last a little longer, but they still develop minor cracking with enough heat cycling. You'll end up replacing any / all of them at some point. In the end one needs to "run the numbers". If OEM drilled last 2 years and cost $xxx and Sebro slotted last 3 years and cost $yyy, figure out the cost per mile or event or year and buy whichever is cheaper.

fnel1771

Irrespective of how you look at it Sebro Slotted are a much better cost and technical solution compared to drilled OEM rotors, lasting up to 50% longer, which is my experience in a DE environment. I run in the instructor group and do a significant number of true open track events also in addition to regular DE's

Hella-Buggin'

Sorry, I forgot that as soon as I had heat cracking issues I upgraded the brake cooling ducts in all four corners.
Still, for the money I found Sebro slotted to be the best bang for the buck.

Scooby921

I wanted to go for the Sebro slotted, but I also wanted FCP Euro's lifetime guarantee so my future rotors are free + shipping. They had rears, but no fronts and I didn't have time to wait for new stock.

petee_c

Thanks,

I decided to get cheap rotors from Rock Auto Should be hear Monday, in plenty of time before my 1st trackday... I guess I will use them as a wear item. I got Pagids for up front and raybestos for rear, standard oem cross drilled versions.

I came across the notion that slotted rotors may accelerate pad wear, something to consider if it costs you over $500cdn for a set of Hawk DTC60 pads....

Quadcammer

For future reference. sebro slotted rotors with pfc08 pads. last forever with outstanding performance. get my rotors at fcp so free lifetime warranty

anthony42hat

This is simply not true in my experience and I believe cross drilled may be harder on pads than slotted.

Rhythmaddict

I just order Zimmerman rotors from FCP Euro with a free lifetime warranty. Send them in when you're done, they give you a store credit, repurchase and install. Rinse and repeat. No affiliation.

etchhead

Thanks for the FCP Euro idea. I had been wondering where to get replacement 350mm Sebro slotted rotors.

Kitc2246

I thought the primary purpose of drilled rotors was to remove heat and trapped pad gas? As already stated they should get too thin before the cracks join. I'm still a beginner at DE's, 14 track days to date. I put on new Zimmerman crossed-drill with DCT-60s. I didn't measure the old ones, but they had a lip. No cracks joined or over 5mm. The old rotors were not Zimmerman, I think Sebro cross drilled. The new Zimmermans and DCT-60s are not squeaking on the street like before. Seems to be different opinions on whether the slotted Sebro's (and pads) last longer, but I would be concerned if they transfer more heat to the brake fluid. The slots can't be providing equal cooling to cross drilled. Just checked the price for front rotors from FCP and will definitely order from them next time. No significant price difference between the drilled Zimmerman's and slotted Sebro. Wish they carried a better (track) pads. Using ATE 200 and added GT3 brake ducts.

09 Boxster PDK w/Sport/Sport+