Going to replace the rotors. Is there a big advantage for normal driving to go with slotted and drilled over smooth. Pros and cons please. Thanks

 

No real benefit for drilled slotted rotors for normal driving or race driving. I understand they cannot be turned, and are more prone for cracking as the holes weaken the rotor.

They look nice.

 

I bought the EBC slotted and drilled and they were TERRIBLE. Vibration after only 600 miles. They made a lot of noise too. Went to NAPA Ultra Rotors in August and they have been GREAT. Smooth as glass. I also bought the NAPA Safety brake pads too. Thread with pictures: https://www.chevyhhr.net/forums/brakes-%7C-suspension-%7C-shocks-%7C-struts-24/brake-update-27189/

 

With the newer composition of brake pads there is no advantage to slotted/drilled brake rotors. Just a bunch of hype from the manufacturers to try to make you think otherwise. Slotted need a gaseous cloud around the brake pads to actually help, the slots would dissapate the gas making the pads contact the rotors more. This does not happen with the newer makeup of brake pads, they simply do not make the gaseous cloud. Drilled only helps in water or mud to help clean out the rotors, if the heat doesn't cause them to crack and possibly break. Both can make the rotors weaker. Improperly drilled can actually crack around the holes. Your vehicle will stop just as good if not better with the stock style rotors. Just buy something aftermarket that you have heard of. The factory rotors and many aftermarket ones are made from inferior metal that simply does not dissapate heat as well, they tend to warp from this. I personally like the NAPA Ultra Gold series. I've had great luck with that. I've never felt that something that looks a certian way is possibly worth my life.

 

Drilled rotors are good to help dissipate some heat in the HHR’s breaks. Especially if you driving hard on them as the stock rotors tent to warp. But there a BIG difference in drilled rotors, some idiot companies just drill castings that were not designed for this, and this will cause problems. However, if you ever get a chance, look at a Porsche, or a BMW, or Lexus with drilled rotors. The area where the drilling is done is specially cast to accommodate the drill hole, not just drilled through the rotor.

Baer breaks makes a DecelaRotor line to fit the HHR and cobalt. And there casted for cross drilling. But I agree with many that for day to day driving the solids are better for long life and repeat machining.

 

I believe when you speak of casting you mean the "drilled" hole is actually part of the cast, there is no drilling involved. The rotors that are more prone to crack are ones that are dirlled and not cast with holes in them.

 

Have the rotors on my HHR and Tahoe and yet to have any rotors crack in the years I have been using them. Even have them on my autocross CRX and no issues. Do they brake better, depends on need. The Tahoe tows a trailer and I feel it does a better good braking and the stopping distance is better. The HHR, well that is more for looks anyway and it braked fine before and brakes fin now. The CRX, well that car is so light it well lock up the wheel anyway.

Yes they can also be turned. The brake shop has to slow down the arbor speed so the bit does not skip over the the holes or slots. I have also had them turned, but many brake shops will not touch for whatever reason.

 

Also drilled rotors take away surface area... or braking surface, slightly reducing effectivity