Ok. But at least do it right. Convert to bigger disks, do it right. Just by putting the same size rotors (but drilled) on you are decrease your surface area by at least 20%. Enjoy your decreased stopping power.

If you're warping your rotors, ditch the 20'*. The 2000 and newer Bonnevilles don't have warping problems like the 92-99 do.

Keep in mind that drilled rotors with a chamfer or blend on the holes decreases surface area even MORE.

Honestly folks, the drilled rotors are WORTHLESS to 99% of the members here unless you're willing to sacrifice braking power in order to have the ricer look. Your choice.

why do they have that problem?

Which Gen? 92-99?

ya 92-99

My dad has drilled & slotted rotors all the way around on his GTP, and is running ceramic pads IIRC. He has smaller than stock brakes on the front of the car (grand am brakes since the calipers are aluminum and the rotors are significantly thinner, saves a total of like 15lbs. unsprung weight and I think like 4lbs. rotating mass). He'* had the brakes on the car for over a year and ~10k miles and has had absolutely no problems with warping or cracking or anything like that. He got them on ebay and I think the whole set was right in the $150 range. Even though the car has smaller brakes then it had originally it stops significantly faster than it used to and has basically no fade, and the rotors look good too! It is primarily a street car, not really a race car, and it is beat on pretty hard. A lot of high speed quick stops on 2 lane roads. (I'm talking about nailing the brakes at like 140mph). Not to mention the car has probably made 30+ 1/4 mile passes with these rotors with some pretty heaving braking at the end since it traps 115+. If it doesn't have any cracks or warping by now I think its safe to say that they are good for typical street use. I'll keep you guys posted on how the hold up over the next year but I don't think it will be a problem..

Edit: Actually now that I think about it these rotors must have been on the car for at least a year and a half +. The whole reason to put them on was to drop weight to run faster while it was still a stock cam car. Since we put the cam in last winter that means it hadn't been raced with the rockers since October of that year (2004) so that means those brakes were probably put on in like August of '04 or sometime around there now that I think about it. So really they probably have more like 15k miles on them and are 1.5 years old.

Shawn

Elmach.....start a topic in General Chat asking your question. This is a section of the Forum that doesn't have that problem.

Shawn, many different rotor offerings out there, and many different driving styles. Not to mention that the BONNEVILLE is prone to warping rotors because of being underbraked to begin with. The GP is a nice comparison sometimes, but not in all cases.

In GENERAL, drilled rotors are BAD for a street car and are a ricer stunt so they look fast cuz their brakes gotz holez in 'em.

Dammit. I wasn't going to do this......

Call some brake shops in your area and ask them if they'll turn drilled rotors. In my area, NONE of the typical sources will. Why? Liability. So many ricers have come back asking for compensation because their rotors exploded. And it wasn't from the turning, it was from micro-cracks because the holes were drilled in the blanks and caused stress fractures. Brake shops want nothing to do with drilled rotors unless they are OEM.

There is NO BENEFIT on the dragstrip or street to drilled rotors, particularly on HEAVY cars. Those rotors you CAN get that have the holes CAST into the blanks before hardening are more expensive than most members here are willing to pay.

Get slotted rotors. They shed water and are able to release gasses from the pads more efficiently, so that the gasses don't build up in an 'air hockey' effect between the pad face and rotor during hard braking.

The slots are machined before tempering (heat treating) and are typically at some angle other than 90° (or perpendicular).

Now you may propose chamfered or blended holes are less than 90°, but that increases the effective 'non surface' diameter of each hole. Collectively, these holes decrease the effective surface area of the rotor far exceeding the benefit (which is none) on a street car.

Slots are different. The benefit from shedding water and allowing pad outgassing escape exceeds the detraction of the surface area lost by the slots.

Off my soapbox. Buy what rotors you think will work or look cool.

actually, my Aurora has warped rotors, our SSEi had warped rotors, and so did the SLE.. I think it'* just cheap GM parts mostly. Mine shake so bad when I'm braking, and braking at highway speeds can be brutal.. The SSEi only pulsated really hard, but we replaced the rotors before they got TOO bad.

I'm glad I read this because I have a nice drill press and was already thinking of a pattern.....now I know better.