Scalloped Rotors?

[Bandit]

I already have the Wilwood big brake kit but after a thorough search through old posts here and other sources I think I kinda screwed up, I have the crossdrilled rotors. I was thinking, as some others have, that if slotted is good, then slotted AND crossdrilled must be great. But now I think I should have gone with solid ones, after hearing how prone they are to cracking...

I am still going to have my front drilled rotors installed and leave them for now, since my car is mostly street-driven at this point. But I am looking into doing some track days in the future and I want to get a spare set of solid rotors and race pads to have onhand for that.

With that said, I was looking at Wilwood's rotor options and I saw these:

So would they work well for some serious abuse? Is there any performance advantage/disadvantage to the "scalloped" shape? I thought it looked kind of different and cool.



Info according to Hotrodsusa:
"Special Optional Scalloped Rotors. 12.90 x 1.10 directional vane. Add this to any of our custom 12.90 front or rear brake kits and you will have an award winning car. Too cool for words. Front rotors use one of our custom aluminum hats. Rears are custom built to fit the Wilwood rear brake assembly so you can upgrade an existing 12.19 x .810 kit to this big 12.90" x 1.10" rotors. Call for details regarding any upgrade or you can add this to one of our famous "Zero Offset" brake kits.

Scalloped rotors also available for 11.75" and 12.19" rotors with 8 on 7" mount in .810" and 1.10" thick.

Scalloped rotors were orginally designed for asphalt racing. How cool is too cool? Paint the vanes red, yellow or green and you have the coolest set of rotors in town."

[GBodyGMachine]

Wow

[Damn True]

Why would you want to give up 30% of your swept area?

[MrQuick]

I remember a thread about this on the old site and someone said it was BS and would never work right. I guess times are changing?

The design makes a lighter rotor without losing breaking efficiency. Cools faster too.

[Damn True]

When it comes to rotors, racers are constantly searching for the ultimate balance between the lowest weight and the ability to effectively manage heat. Decreased rotating weight in the drive line provides quicker deceleration under braking and quicker acceleration out of the corners. Lower weight also benefits handling with improved spring and shock control over the unsprung suspension mass. Wilwood's
ULD - 32 drilled and ULS - 32 scalloped iron rotors provide two highly effective lightweight options for sprints, late models, modifieds, and other competition applications that race in low to medium temperature ranges.

View technical drawing

ULS - 32 Series Scalloped Rotors feature a fully machined scallop configuration that provides the highest degree of weight reduction on a vented straight vane iron rotor. Scallop machining will remove as much as three pounds, or nearly 33% of the rotor mass. The vented castings provide increased cooling capacity over machined steel plate rotors, with improved structural durability over drilled rotor designs


That does not sound to me like the description of a part suited for an auto-x or open track environment. With less material (33%) they would be less able to deal with sustained high heat cycles. Again, why would you want to give up over 30% of the swept area?

[LS6 Tommy]

I think I kinda screwed up, I have the crossdrilled rotors. I was thinking, as some others have, that if slotted is good, then slotted AND crossdrilled must be great. But now I think I should have gone with solid ones, after hearing how prone they are to cracking...

Cross drilled and/or slotted rotors are mostly eye candy due to the fact that modern pads that don't off-gas anywhere near as much, so it's not needed except for extreme use or full-race applications.

Tommy

[chicane67]

Add this to any of our custom 12.90 front or rear brake kits and you will have an award winning car

I cant wait.

Serious abuse ?? Maybe for a light weight chassis... but not not for a heavier chassis and a road course, for too long anyway. Its gonna play hell on your brake pads from wiping on and off the edge of the rotor.