Thinking ahead for more mods I wanted to gauge the community your feelings/experience with C5 rotors. As in plain vs cross-drilled vs slotted. I had a set on my '68 Camaro that I had made in Florida by Aerospace Components (don't know if they still in business). I was stationed at SAC and I had a TDY/AFI in Florida on my way to Langley. Stopped in their place, took a tour of their operations then told them what I wanted and the purpose. After 3 months they were ready to pick up. Too much to ship plus i wanted to see them to make sure it what I wanted. They were only slotted and not cross-drilled. This was in '80 so they are old today I still have them but not on the Camaro just in storage.

Anyway what are your ideas because I have heard some scary stories about the cross-drilled versions cracking up under pressure. Don't know if was just a mfg issue or just bad quality but I want to be safe. Oh and she is a DD but once a month runs the traps just for fun. Cheers!!!

 

If the holes are cast and not drilled (e.g. brembo) they can help with cooling. Drilled holes are just putting a dotted line for cracks to start. Even cast in holes that is where the cracks start because it's a cold spot.

the slots can add some extra bite depending on the pad and maybe help with taper on the stock caliper I guess.

Bottom line is both features add substantially to the cost of a consumable item, although I'm not aware of a high quality, high vane count, rotor ring that *doesn't* have slots or holes.

If you only drive on the street or drag strip it doesn't matter, buy what you think looks cool and won't rust over time.

I am using the $75 kns blank rotors and starting to get some cracks starting after some back to back session at gingerman where there are several hard braking (>1G according to GPS) zones every lap. Still plenty of life left until the cracks start to spread. Easily will be able to finish the year on these.





Far FAR more important is having good pad, and good fluid! And keeping your caliper seals and slider pins in good condition!

 

As above, if you are driving like a hobbyist, I would not worry and get a reputable brand that you like.

 

I just did my brakes again after 2 months. I used my old drilled and slotted rotors at an HPDE, yea, front cracked in 3 spots, rear cracked in 1 spot. I had new hawk HP+ pads on there which got chopped up. So I now have new hawk pads again and AC Delco gold from rock auto. Slotted, not drilled, only 55 a piece. 2 months ago, I also put on stainless brakes lines, brake flush with hawk HP600, bilstein B6 shocks and c6z51 sway bars. Worked great at an HPDE. Hawk HP+ pads do squeal a lot, bite hard at most all temperatures, great entry level track pad that you can daily drive if you can handle the squeal. Lesson learned, don’t use a drilled rotor at HPDE. Slotted ones are fine and still look good. Rockauto.com has decent prices. They also sell Raybestos track pads which I heard from a forum member are decent track pads. Advanced drivers might need something better though.

 

Unless shelling-out for some of the bad-boy racing rotors, everything you get will be chinese, so get the sit-down restaurant version of chinese, and not the buffet version. (buy the better versions if you can....the NAPA Adaptive Ones are pretty nice)

 

I currently have Powerstop Z23 brake rotors that are both drilled and slotted. They are paired with Hawk HPS 5.0 pads. They dust a lot, but they have worked well. My next rotors will be slotted only. I do agree that for your use whatever you like will work just fine.

 

Added footnote: I'm also running the Powerstops-slotted only (also with Hawk pads), but I had them cryo'd...wow! it's been about 8k since installing, with some hard, hard driving, and they still have the original machining marks....cryo is awesome!

 

great street set up right here by warlord. Check out the Delco slotted at rockauto.

 

Here is the facts on Rotors. I have been through the brake training of Willwood, Hawk, EBC and a number of others. They all stench the same thing.

Drilled rotors are cosmetic today. Years ago they were drilled because the organic pads out gased. Also they drilled them for less unstrung weight in light weight formula cars.

Holes do not cool. The fact is the more metal the more heat absorption and the better the stopping. Rotors are heat sinks that draw heat from the pads to keep them from fading. Drilling holes removed the capacity to absorb heat.

The best rotor you can buy is a solid rotor. The factory GM ones that are treated not to rust are about as good as you can get.

As for slotted or rotors with groves. They do work to remove water, rubber, mud etc from the rotor in racing, on the street they sell them as the head of EBC said is to make money.

They are mostly cosmetic on the street.

Drilled rotors for the most crack and wear pads. Only a hand full are made very well like at Porsche where cracks are rare.

Most honest companies will state they are not for track use.

So buy what you like. As long as it is for cosmetic they are fine. If you intend to do track time I would avoid them. Like racing pad you don’t want to use them on the street or slicks in the rain. .

Some will want to argue this and that is fine. Those who do not believe the truth just pad my 401k more.

I used to believe all the hype before I I started to work with these companies. And over that time I found how misleading some things are. Most companies are honest but there are some not very honest ones out there too.

Note if you also look at most race cars today from IMSA, Indy, NASCAR and others none use drilled rotors. Only some drag racing applications or sprint cars did just for weight savings and they only use brakes limitedly.

The IMSA Corvette run solid rotors with just a few groves cut into them.

 

I hope the factory GM rotors are better than the C5 OEM's. I went through three sets of fronts in quick succession on my then brand new C5 due to judder under normal braking (road use only). At least warranty covered the first two sets. After that I gave up and bought a set of Baers.That was about 20 years ago and to this day have never had a problem with them.

 

Not the rotor.

Two things happen.

1 the bearing if out of spec will wobble just a little and wear the rotor in uneven thickness. It is call Rotor thickness variation. People mistake it for warp.

2 the other issue is the pads were never bedded in. Even on new car you need to go out and make a series of hard stops with out fully stopping to coat the rotors evenly with pad material. If not the pad material on a hot stop can have material stick to the rotor in that spot making them grab and pulse.

Dealers really never bed pads and that is why so many have this issue.

Odds are who ever put the other rotors on either bedded the pads or changed pads and the new material is more resistant to sticking.

Or you just got lucky.

You can get a rotor red hot and not warp it but it could glaze.

Pads today are no where as good as they used to be. That has not helped either. S\Things like copper and other heat absorbing materials are banned for the environment.

 

Regardless-It doesn't speak well for C5 rotors when you change to Baer, and no more issues in the next 20 years.

 

I pretty much agree with you. One thing that may help guys that drill the rotors is a heat treatment known as normalizing. That and checking for any stress risers like burrs, etc. Normalizing may cause other issues that may require a light re-machining to true up the rotors. My .02

 

No it may have been they were just installed properly.
Don’t make this into something it’s not.

Everyone thinks they know how to do brakes. But things have changed much today and many never kept up and continue to suffer repeated problem.

 

Those are SWEET! For only $60 ?? And AC Delco no less. I'm in thanks for the lead. What calipers are you running, C6? Dustless pads? Cheers!!!

 

stock calipers with Hawk HP+ pads

 

Stock AC Delco because you aren't putting the car on a road course...

 

Not that complicated. Before Chevy would replace them under warranty, the dealer had to set them up and measure the run out. They had significant run out so they were replaced for free. In each case with OEM rotors, they were fine at first, but after about 3 months or so of (road, not track) usage they started to judder under light braking.

As to the Baers, I did them myself, with of course new pads as a precaution.

 

The magic of pads.

 

C5 OEM rotors ARE factory GM rotors...