On the camaros, are drilled and slotted rotors worth the extra moolah? How many people have them?

 

There is a forum for "brake" questions. Doesn't belong in "LT1 Engine Tech". Moving....

 

They're eye candy, aka driveway jewelry only. Thats on any car, not just f-bodies. They're still usually better than the stock junk though.

 

If worth means $/performance ratio, then no. Seeing as they are more susceptible to cracking under high stress use, you're not able to get them turned like a regular rotor, and they don't withstand or dissipate heat as well, I think they're strictly for people who think parts that look fast/cool are better than parts that are actually fast/useful.

 

Yes they are a little more susceptible to cracking but what rotor isnt going to crack if continuosly race at 120mph and slame on your brakes, not that much more susceptible IMO, and yes they do dissipate heat faster than stock rotors would. I mean why would all the racing formula 1 cars and exotic cars have cross-drilled rotors if they dident work. If the ferrari enzo and porscha 911 have cross-drilled than I think the rotors are there for a little more than just looks

 

A picture is worth 1,000 words, or so they say. The Baer cross-drilled rotor on the right in this picture has 4,000 street miles on it. The one on the left was cryo treated, and has 19,000 miles on it including the Silver State Classic and some auot-x.

http://www.ws6.com/cryo.htm

I don't think the Enzo uses cheap drilled rotors from e-Bay Even the Baer site used to have a page that described cross-drilling as purely cosmetic.

 

They're called solid rotors. They'll warp first.

Enzo's and Porche's from what I've been told use cast in holes not cross drilled. That makes a difference. I've also read where a Porche engineer said that they went to "crossdrilled" rotors because the customers were whining about wanting them w.their expensive car, not because they were better.

 

I've used solid Brembos for 4 hours of actual track time, plus used them for 16 autocross events with a co-driver. Finally developing some thermal cracking. Can't imagine having drilled.

As for the F1 comparison:

First, an F1 car weighs about 1323 pounds WITH the driver.

Second, F1 brakes are carbon, not steel. BIG difference.

Third, how long do you suppose that rotor remains on an F1 car?

 

the idea with cross drilled and slotted is exhausting the gasses that build up allowing for better heat dissipation

as for cracking, if the holes are not chamered they are considerably weaker than if they were chamfered
this is beause a perfect edge is more prone to cracking that a rounded edge

if this is a street car, then go for looks, because the quality cross drilled rotors will last and perform just as long and well if not better than stock

i personally have crossdrilled rotors for an ls1 brake setup on my 3rd gen, and i'll let u know how they work out after a few miles, if/when they crack i'll get a set of baer decala rotors (almost $300)

 

Thats exactlly my point, no mater what type of rotor someone uses whether it be crossdrilled, solid or slotted, if u drive hard enough all of them are eventually going to warp and crack.


And I wasent really comparing f1 formula cars to ours i was just trying to say that f1 cars use drilled rotors. And even if they do weigh 1350 WITH a driver they still drive up and above 170mph for hours upon hours. 1 race for there cars is about 1 year of use with our f-bodys if its just your daily driver.

 

Modern brake pad compounds DO NOT have out gassing issues like older compounds. You're buying into a marketing ploy to get you to buy the crossdrilled stuff.

I beg to differ about them lasting as long. My wife's car has 135k miles on her rear rotors and 75k miles on her front rotors. I seriously doubt you'll get any crossdrilled rotor to last that long.

What are you going to compare your crossdrilled rotors to? The stock crap? Are you going w/new pads also? If so, I guaratee most of the better feel will be from new pads.

Rotors are a heat sink. The larger/denser the rotors is, the less heat that will be transfered back into the pads. Drilling or slotting your rotors reduces mass thus letting them get hotter quicker. How is this better? Don't even think about giving me the propaganda about the holes creating circulation. Do a little research and you'll find that only vented rotors and ducts will help the air circulate better. Don't take my word, go onto the SCCA board and ask around.

 

The point is they're also a far higher grade of material than you'll ever run. They also have a serious brake cooling system and the rotors are vented.

You are trying to compare relatively exotic rotors that have been engineered to certain specs to some run of the mill factory replacement blank that some machinist drilled holes into.

 

So slotted only is the way to go? What is the theory behind a "dimpled" rotor? DOes it achieve the same thing as slotting? I need to put some rotors on my 3600# street/drag car that Pops and I are building, I want that beotch to stop from(what we hope are) 128/130 Mph trap speeds.

What are the best pads for this application? I put some Raybestos Pro-Stop on my Honda and I like them, or should go with a Hawk pad?

David

 

As many have said, cross-drilling and slotting are purely cosmetic, and modern pads DO NOT produce any gases that need to dissipate. The one and only advantage I have ever experienced with slotted rotors (not crossdrilled) is that in the rain, the slotting will act like a windshield wiper and help keep your pad as dry as possible. But even then, the difference was marginal...

 

My original front factory discs and front pads stop my 3,760# car fine from 128mph trap speeds. Look at what Mark Williams or Strange sell for drag cars.... the front rotors aren't even vented, the whole assembly is small enough to fit into a 15" wheel and they weigh about 1/2 as much as the stock setup.

This is a Mark Williams unit from a 3,525# 30th SS convertible that ran 160mph trap speeds - he seldom pulled the chute:

http://cjcfo.fbody.com/members/injun.../DCP03831a.jpg
http://cjcfo.fbody.com/members/injun.../DCP03810a.jpg