BMR Sales2

iTrader: (40)

Drilling and slotting rotors gives the benefit of scraping the pad every time the brakes are applied at the expense of wearing down the pad material faster and drilled rotors will crack. Doesn't matter if the holes are cast or drilled THEY WILL CRACK. Slotted rotors will also crack if the machining process on the slots is not done correctly (ie too deep or too wide) and if the slots are too close to the outside edge of the rotor. Yes the drilled rotors also relieve the built up gasses that come from the braking process but they were originally made for brake pads of yesteryear. The technology in brake pads nowadays has cut down on this "gas" to the point where a good slotted rotor will do the trick if you are worried about this.

Another thing to think about is what kind of tires do you have? Not how wide or big they are but what kind? People seem to forget that brakes don't stop the car, yes that's what I said, the TIRES do and buying cheap tires is almost always going to be the problem.

wht01ws6ta

iTrader: (45)

FWIW, I believe a lot people say drilling/slotting is better because they go from stock rotors (which suck bad ask anyone who has had them warp repeatedly) to a set of drilled or slotted or whatever aftermarket rotors and better pads. If the quality of rotors and pads is better the braking will be much better, even if there is less rotor mass from the removed material.

I went from sucky stock brakes and warping rotors every couple thousand miles to Brembo crossdrilled rotors and good pads and it was an amazing improvement. However, after about 40,XXX moderately hard miles the front rotors have stress cracks(although they have never warped and braking was still good and still smooth) so I ended up doing a C5 conversion and, again, that is a big improvement and this time I got Brembo blanks to avoid the stress cracks. Blanks are also cheaper than drilled or slotted...

Sam Strano

iTrader: (41)

Incorrect. In fact both take swept area away from the pads. Blanks offer the most rotor to pad contact area. And it's a myth that either run cooler than blanks.

Drilling in fact can raise temperatures due to the disruption of airflow in the vanes of the rotor. Slotting is for outgassing.

BIG_MIKE2005

iTrader: (116)

^^Listen to this man & read the sticky. Too many people still believe the BS sales pitch of the drilled/slotted rotors sales people.

Just grab some Brambo blanks & good pads when it's time to do your brakes. But if this problem just started after the tire swap I'd say you bought a incorrect sidewall series tire & it's throwin the PCM off.

Sam Strano

iTrader: (41)

Exactly right... Excellent post, could not have said it better myself.

If you have to use something that looks cooler than blanks that's fine. All slotted rotors are not created equal.

The ATE rotors I carry are slotted, but are much better than the aftermarket cut blanks. In fact ATE does not make their rotor in a blank, and the slots are not typical.

#1: The slots are shallow, and only extend to the minimum wear thickness depth. Meaning when the rotor is truly worn out the slots actually disappear.

#2: The slots are elliptical. No sharp points or edges to act as stress risers which are starting points for cracks

#3: They come coated so the edges and hats do not rust

#4: They are a real quality rotor, made by a German company that makes OEM parts for most every German car company. This is not cheap Chinese junk.

You can see the ATE rotors (and Brembo, and other packages that include pads, as well as kits that are complete having rotors, pads, stainless lines and fluid) here for LS1 cars: http://www.stranoparts.com/searchbym...D=17&ModelID=7

z28bryan

iTrader: (7)

No

There's a ton of misinformation in this thread. And I'll do my best to not to contribute more to it here...

I'm not quite sure how the taller diameter tire effects the ABS, but I heard it can have an effect on it. Maybe someone else can fill in?

If you went with a tire that has poor traction compared to your previous tire, it will skid with less braking force than it did before.

If diameter is equal to before and you rule out any problems with the car and ABS, then going to better stopping brakes will only make it easier to get into ABS. Think about it... your getting in ABS now because you have enough force to make the tires skid... getting better braking power won't help prevent the tires from skidding. The tires will skid more and you won't be anywhere close to fixing your problem.

So question is what did you have before for tire size, wheel size, tire brand and model, brake pads, brake rotors.... and what do you have now for all of the above?

Drilled slotted rotors is the least of your worries in fixing your problem. Your better off ending that discussion in this thread now

Sommer86

iTrader: (46)

If anyone is looking for a C5 conversion, 6litereater (a sponser on here) sells one with C5 rotors and brake lines and all that is needed for the swap and install.

6litereaterdesigns.com

DONAIMIAN

iTrader: (18)

You said you noticed the problem after changing tires? That should tell you the problem right there, and that should be the end of discussion.

As for drilled and slotted rotors, im not even gonna get on that one.

z28bryan

iTrader: (7)

I agree. Assuming no issues with the car... If your hit the brakes and the car doesnt stop but the tires roll, then your brakes/brake system is the weak point. If you hit your brakes and get into ABS and skid your tires, then your tires are the weak point. Your brakes are not.

Ironhead

You guys haven't left anything for me.

I guess I'll take this one...

Please realize the following:

1) When pressed on the issue, GM engineers have admitted (although very unofficially and very quietly of course) that the drilled Z06 rotors were a "marketing" and "aesthetic" decision.

2) The ZR1 has... ummmm... carbon ceramic rotors. That's like comparing apples to acorns.

Brakemotive

iTrader: (73)

Just wondering where they said that? In 2006 GM engineers did a whole study on Drilled rotors, and published a paper with the SAE on the effects of cross drilling rotors. If you want proof of this or want to see the results yourself it is SAE Technical Paper 2006-01-0691. I would think GM's performance testing is the reason the Corvette and many other high end cars have drilled rotors, not just for the looks.

Wesmanw02

iTrader: (4)

First off,I'm not a newbie or something, so you can take the your superiority complex and stick it.

Second, do you have a source for that information, or is this just word of mouth?? Sounds more like a rumor than anything factual.

wabmorgan

If your overall diameter is off.... not the same front to rear.... that WILL kick your ABS.

z28bryan

iTrader: (7)

Simmer down there Seargent Sally. I didn't see anything there that was very insulting. Some of you guys are too sensetive. Ironhead typically knows what he's talking about too unlike a lot of people on here.

Sam Strano

iTrader: (41)

If you have massive 14-15" rotors and big pads on a lighter car that's better balanced (and therefore the rear brakes share more of the load) then a rotor that is *designed* to be drilled can be fine.

Meanwhile I notice the 556hp, not exactly light CTS-V doesn't have drilled rotors.... Makes you wonder, don't it?

BIG_MIKE2005

iTrader: (116)

^^ I believe I'll listen to advice from a multi time SCCA winner over some BS in a magazine any given day. Thats a big problem with real world results with solid testing & scewed testing to make a product look better than it is or make people think it'll work the same on every application. (like the difference in overall vechicle weight effecting braking as mentioned above)

JD_AMG

I was just going to mention this. The CTS-V's base brakes are slotted, yet the optional "track package" replaces those with blank rotors...

photoman9988

Well I went from 18's all the way around to 18's in the front and 19's in the rear. tires are 265/35/18 and 295/30/19. Could this affect it?

Sam Strano

iTrader: (41)

What is the OD of each tire? Much difference in size, as mentioned, will mess with the ABS big time.

photoman9988

The old setup was 245/40/18 all the way around.