[justpete]

Originally Posted by Cloud9blue

I personally wouldn't go with those open-slotted RB rotors if you are going to put some serious amount of heat cycles into them. Those huge open will act as stress concentrator, the same way that drilled rotors do when undergoing heavy track abuse.

In addition, it seems like they have some pretty major quality control issues as well. The S2000 and various JDM forums reported cracked rotors from them after just a few track days, from the searches I did last year when I was considering them as an upgrade to the stock one-piece. I can only imagine the issue would be more prominent with our 3600lbs e9x.

If someone like Girodisc or Performance Friction makes a two-piece rotor with just a simple and tested slotted disk, I would buy it in a heartbeat...

Anyway, the ECS kit is overpriced gimmick... If you want a Porsche branded caliper, go for it. For the same price, you can get a properly fitted Stoptech 6-pot that is actually designed to work with our brake distribution...

All good points. I'm aware of the discussions about QC and about cracking on the surface of RB rotors but I consider that normal. I'm not sure QC is still an issue these days but we'll see. The open slots will act as stress risers and yes they can lead to cracking of the rotors, possibly catastrophic. But I'm not putting as crazy a thermal load into them as most since my car is a momentum car.

I still have the Stoptech Sport slotted rotors as backup and the Zimmerman 135i front rotors aren't particularly worn so they'll be around for backup too. The only concern is how much abuse the pads will take from the slots or how quickly if at all the slots will get filled up with pad material.

It'll be fun to try them if nothing else. Will probably put the slotted Stoptechs back on the rear just to keep them visually similar and to have the same ratio of available rotor surface although I don't think that matters all that much. It's a science experiment!

They don't recommend using their rotors with Carbotech pads but that's another bit of experimentation as I'm not convinced it's a real problem in my use. If so, them's the breaks. Maybe I'll try some different pads, dunno. Not a big deal really.