Fact or Fiction: Drilled/Slotted rotors improve braking
 

This should be an interesting thread since so many Corvette owners feel that drilled/slotted rotors are just "Bling-Bling". As the title says, state your position and back it up with any facts available.

I posted a similar inquiry on the General section a couple of months ago. The consensus was that drilled rotors are mostly just bling bling. As I understood it, they are generally not used on the race track. That itself suggests that they do not enhance performance at all...

The idea of drilled rotors was intended to increase cooling. It probably does on rotors that are designed for this. StopFORCE rotors are the only rotors that have demonstrated the holes are useful. Also, the drilled holes cause the rotors to crack around them from heavy braking. Lots of force. The slots are designed to help 'outgassing' or hot gasses that build up between the rotor and the pad to escape.
I agree with Red Racer that it's bling bling, but I just bought a set of AC Delco slotted and drilled rotors. They look sooooo nice on my buddies car. :cool:

Heh, I thought the holes were to help with outgassing, and the slots were to wipe the pad. Any sharp edge on the rotor creates a stress riser. The inside edge of drilled holes are sharp, thus they are stress risers. For facts about stress risers, read some of the books in the C5 General Sticky, Mark's Handbook for Mechanical Engineers, or just do a search instead of asking other people to do it for you. You're asking a newbie question, so please educate yourself with some heavy search feature action, and then come back and ask more questions.

Don't get your panties in a bunch and don't think for a minute you can get away with intimidating people in a public forum. Do your own searches in this forum and you will find that all threads on drilled/slotted rotors are just opinions and not based on facts.

No one I know here races with them. New pads don't need out gassing. We are convinced, now you can do research if you like. Try all the major race brake vendors. Some AP's have small hook like cuts about 1/2" in the rotors but they have sponsors and don't worry about cheese graters or cost. Go to a AMLS race and see what is in the pits.
Bling :seeya Bling

If you are heating up your rotors to the maximum allowed temps in a racing situation, slotted would be your best bet. If you are pushing it hard but not to where too much heat is a problem a solid rotor would be good. If you just drive your car around very carefully and want it to look pretty, then get the slotted, cross drilled and zinc washed rotors. Hell, might as well get them gold plated... :rolleyes:

VR :cheers:

Best performance rotors are solid rotors, period. Go to corner-carvers and look up some threads on slotted versus solid and you'll know then.

THere are probably some MINOR benefits to slotted/cross drilled rotors, but not near enough to make up for their main disadvantage of not being able to take the heat as well as a solid rotor can. If you are not on a road course, there is no way to heat them up enough for it to matter. Most of the improvement that people think they feel when they get new rotors is from fresh brake fluid, not the rotors

Here we go again :rolleyes:

http://img.photobucket.com/albums/v1...ackedRotor.jpg

http://img.photobucket.com/albums/v1..._Rotors001.jpg

and this one is after only 4 HOURS of track use on Porsche GT3 cup car

http://img.photobucket.com/albums/v1...rscheRotor.jpg

And in the Pits of a Grand-Am race

Caddy CTSv
http://img.photobucket.com/albums/v1...CTSvBrakes.jpg

AP racing on the SunTrust car
http://img.photobucket.com/albums/v1...bigbbrakes.jpg

Performance Friction Brakes
http://img.photobucket.com/albums/v1...-BigBrakes.jpg

and the C5R
http://img.photobucket.com/albums/v1...-rearbrake.jpg

Now where were those drilled rotors???

From the Stoptech web site: http://www.stoptech.com/faq/

From Wilwood: http://www.wilwood.com/Centers/Infor....asp#question7

Make it simple:

FICTION

Cross-drilling:

They where created to allow gas from the pads, out-gassing, to escape so it does not create a barrier.

They where never meant to be used for long, one race and in the garbage.

No modern pad out-gasses anymore until the temperature gets so high that the brake fluid stops being fluid and goes into a gaseous state.

Now the "hype" is that they improve cooling. And on a brake dyno test stand or in simulations they do somewhat. The theory being that air is drawn through the holes and out the vents.

In the real world, they don't because the air flow is way too turbulent. You turn the wheel, the car moves up and down, sideways, etc., etc.

It's old technology for an old problem.

Slotted:

Where also created for out-gassing, actually slotted rotors where invented because drilled rotors cracked so badly and so often.

Slotted rotors do have a slight benefit in the real world of "pad cleaning" which is basically scraping a very thin film off the pad. It actually does happen, but it probably has no effect on braking distances. And not worth any extra cost. For an out and out race car it's probably worth it because they can use every little 1/1000 of a second.

Slotted rotors will increase pad wear noticeably.


Damn - Au is fast :lol:

:lol: One of my :mad: HOT buttons. Unscruppulous marketers using OLD & outdated information to make money fromthe uninformed and uneducated consumer.

:cheers:

Riiight... I said drilled rotors have a sharp inner edge. What makes you think that's not a fact? You're not paying nearly enough for each individual hole to be chamfered from the inside. That doesn't even have to be fact or opinion, that's just pure common sense. I also referenced two books, one of which is very popular among racers, and the other book is a common reference among engineers.

You discounted all the posts by the forum members when you said "all threads on drilled/slotted rotors are just opinions" and almost all the information in this thread is from this forum. You do realize this is also a drilled/slotted rotor thread don't you?? I gave you good information, and solid offline references, but if that's not good enough for you, you're not just a newbie, you're a hopeless newbie.

FWIW, this is what I am running.. 13.60" 2 piece SOLID rotors, 6 piston fronts, 4 piston rears, 2 diff kinds of compounds for street and track. I purchased 2 new sets of custom built wheels (one for street, one for track) to fit over the monster calipers... serious brakes are no joke, not cheap but will work much better than OE systems.

http://temp.corvetteforum.net/c5/vet...brakes_010.jpg

http://temp.corvetteforum.net/c5/vet...brakes_008.jpg

VR :cheers:

:iagree:

Good responses, I believe the C5R team utilize a slotted rotor for gas venting, not for cooling or added stopping power. As for mechanical application, more surface contact, more friction, more ft-lbs pressure, better braking force = less travel.
So who cares, drilled rotors do look good, but I will stay with my solids. In a wet emergancy situation your life is better than mod looks. :steering:

As stated cross drilled are pretty but not good

Slotted are better but still a waste Both is stupid, you are loosing surface, and you have a weak rotor, not the best option.

vetterdstr - no matter what people say about the aesthetics of drilled/slotted, I think those look awesome...and I bet they stop like mad...

Actuly they dont stop better. That is why you DONT see them on race cars as in the photos AU N EGL posted above.