Eric-
that comment was in regard to cross drilled rotors.

thicker is better

 

I found that article on the aluminum rotors...

 

But then there is this quote from the "Eradispeed" link embedded in your quote:

or this quote from http://www.baer.com/Products/EradiSpeed.aspx


Seems like some confusion as to exactly what they are made out of......

 

Eradispeed is a one-piece design, with cast iron rotor and cast aluminum hat, or center portion. Similar to the cast iron cylinder liners used in the cast aluminum LS1 block.

Eradispeed+ is a two-piece design with cast iron rotor bolted to a forged & machined aluminum hat.


Aluminum does not make a good friction/wear surface, too soft, and it galls easily. Thats why the Eradispeed rotors still use cast iron on the wear surfaces.

 

Interesting day for this thread to come back some.

I’ve been looking in on the Coca-Cola 600 and right now they’re having a discussion about how they’ve been decreasing brake sizes on the cars for the assortment of reasons that I’ve mentioned here, but how that has made the heat tolerance of the rear brakes closer to the ragged edge of what will absorb sufficient heat to keep things happy (Earnhart Jr’s rear brakes have been having assorted problems and he’s been in the pits a couple of times now in the last few minutes with them on fire).

200mph, heavy cars, no slots, no vents… and the smallest rotors that they can make work… you’d think that if there were advantages to those things they’d have them…

 

NASCAR does slot the rotors.

 

Betcha you won't find them on every car, just as you'll notice a mix of slotted, drilled, and solid rotors in Superbike pits. This tends to indicate more of a personal-preference sort of thing, as if there was an advantage to any configuration, everyone would run it.

I think the bottom line here is that there's no apparent advantage to manipulating the rotor at high levels of racing, and that this sort of thing can cause a durability problem on the street. With those two key pieces of info, it seems that solid rotors are the way to go unless you've got the engineering smarts to design a safe "drilled" rotor (and even then, it's primarly useful as a cosmetic enhancement).

Trey, thanks much for clarifying the thick-vs.-thin issue with drilled rotors, as much as I hate having my intuition countered by hard evidence

 

no problem

 

This has been bothering me for days now; you're telling me that modern pads don't produce any gas? B.S., last time I checked anything that burned or heated produced some type of gas and anything producing gas from under the pads would not allow complete contact to the rotor becuse of the gasses produced from heat and friction. I'll also tell you that I happen to have a set of cross drilled rotors on my Z28. they may not be the highest of quality like the Baer's (they are Power Stop) but I personally have seen the joy of having such rotors on my car. I swear I can stop 15-20' sooner than when I had the stock rotors on. Maybe I'm full of it but no, becuse I have these rotors and they DO WORK! If it's about how long they will last I don't think that matters considering that we are the types of people who smoke tires just becuse we can. But hey, that is my opinion. What's a guy to do ? Oh, and when it rains, excellent! Again, if my favorite sport is using these types of rotors then I believe that they work. I'm not trying to flame but hey, sometimes real world use is the best way to test these types of things.

 

I strongly disagree. Modern day pads produce a negligable amount of gas. Youre really splitting hairs when your trying to measure that gas. In the real world- blank rotors will stop faster. I think that braking thing is in your head. 20 feet is a LOT to knock off if your regarding a typical 60-0 or even a 100-0 stop.

 

Just out of curriousity, can someone explain 2 peice rotors to me and their benifits?

 

anyone?

 

Weight savings. A billet or forged aluminum bolt-on "hat" replaces the integral cast iron hat used in 1-piece brakes.

 

Yep - significant improvements in unsprung weight can result. But then you need to worry about ripping up the hats with the wheel studs under heavy braking (probably not a concern on race vehicles where money grows on trees and rotors are consumed much faster than hats).

You can also float the rotors relative to the hats, which allows them to radially expand and contract as they heat and cool. Many motorcycles employ this design very effectively, but it does add complexity and can cause some weird noises. It seems like the Wilwood setup on the back of my friend's Mopar uses slotted holes to attach the rotors to the hats which floats the rotors somewhat (the bolts still clamp the rotor to the hat), but it's been a while since I've looked at it.