QUOTE(John @ Aug 14 2007, 09:40 AM)
Do vented rotors offer more warp resistance over solid rotors?
In my mind they would due to the additional support structure internal to the rotor (i.e. the vents).
Specifically, I am looking at 914-6 rear rotors (solid) vs 911SC rear rotors (vented).
Looking at rotor design is not enough when considering propensity to warp. The manufacturing PROCESS is equally important. The casting process, especially how it is cooled, how quickly, and if any outside stresses are imposed on the rotor all factor in. After machining, adequate heat-treat/stress relieving is quite important. If there are assymetrical stresses "built" into the rotor, careful "breaking in" can/will still release these stresses, and result in warpage.
That being said, whatever you end up buying, get a good brand (like Brembo). They know what they are doing, don't cut corners, and the cost/rotor is actually pretty decent. Check out TireRack and Tires.com for their pricing.
Avoid the "Slotted and Drilled" style of aftermarket rotors. Every sharp corner machined creates an apportunity for stress cracks to propogate. The stress induced can be wholly from the heat dumped in by hard braking, and/or, any inadequate stress/relieving done while manufactured.
I've gone through enough rotors autocrossing in a (heavy) Mustang GT to have some personal experience with this