Plain VS Slotted VS Drilled Rotors -- what say you EOE?!

[Thundergod]

So in tandem with the USED EURO-IMPORT thread.

I have a 2000 Audi A4 2.8Quattro. Bought it as a certified used (lease end return)....beautiful car, drives like its on rails.

But I have now entered the second tier of ownership. Car was fully paid off 5 years ago....its now six years out of any warranty it may have had.

118K on the clock.

Long story short -- I'm now an Audi mechanic-lite. Im redoing the front brakes coming up and have already made my purchase online for new rotors and pads.
--

But the selection process for brakes is somewhat strange. Many list Standard, Slotted, Drilled, and Drilled & Slotted. In my research I could not really find any
good references on the benefits of the different types. Just general info -- IE Slotted and drilled improve cooling and remove vapor, dirt and water from the brakes more quickly.

So how does everyone feel? Some people on the inter webs believe that its a worthless upgrade unless its a track car and that you should only use standard rotors for
commuter cars.

Others think that its a good upgrade regardless due to the improved brake response WHEN you need it the most.

But I tend to drive my AUDI like....well....and AUDI, and we have plenty of canyons to keep the brakes warm around here. So I chose to upgrade, doing the labor yourself you can save a lot. Didn't go for Caliper and SS lines however...

SO WHAT SAY YOU EOE?

(PS -- I chose the EBC Sport Slotted Rotors and RED STUFF brake pads)

Incase someone is wondering -- a Clutch replacement on an AUDI runs around $2500. Getting more quotes however....

[viffergyrl]

I upgraded my Acura TL brakes to Stoptech slotted AND drilled rotors and pads.   M.Brane was experiencing brake fade with the Brembo solid rotors when driving the car spiritedly on Hwy 33 (the twisty, downhill bits). No problems since.

Reading on the forums, this subject tends to be like oil threads; everyone has an opinion. Some feel the slotted, drilled, or both mods to rotors reduce structural integrity while others tout the cooling ability. Others make mods to the front of the car to increase airflow. It depends on what you are doing with the car. Those modding the front are racing their cars. Those debating the whole slotted, drilled, solid whatever were doing occasional track days with their car and/or desiring higher performance from the OEM brakes. The original OEM rotors had known issues with warping and I had replaced those with the Brembos. I've never done a track day but was interested in a little more performance for highway driving.

The slotted and drilled rotors look mighty cool and solve the brake fade issue for spirited highway driving. I would advise that you not overthink it too much. Buy something that pleases you based on your use of the car. If you are not racing or doing track days with your car, you probably have a number of choices. YMMV

And yes I bought new rotors and pads so my boyfriend could drive my car.  

HTH

[Thundergod]

I agree about not over thinking it....Im of the opinion that Slotted and Drilled rotors are a technological improvement to the basic design. If all the Moto GP bikes run them, and most
high performance cars are equipped with them -- that has to evidence their ability.

You pay a bit more for slotted/drilled rotors. Sometimes A LOT more....so most of my decision came down to reputation and price point.
From what I have read the slotted rotors run pretty silent compared to the drilled. I went with the recommended set up from EBCs website
with the Red Stuff pads for reduced dust and quiet running for euro-sport sedans.

I found the EBC rotors and pads at http://autoplicity.com/ for a screaming deal. Roughly $70 less than anywhere else.

Now for something shiny.....

[viffergyrl]

I bought mine as a special deal through the Acurazine forum. Yes, they can be pricey. Paid around $600 for all four rotors and pads. Included shipping.

[evilted]

For my money, I'd go with slotted.  

You can find plenty of discussion on the interwebz about cross drilled rotors developing cracks after periods of occasional heavy use (i.e., the occasional track day).   Cross drilled look the best, but for the application you have in mind I don't think you're going to realize any performance benefit over a good slotted rotor.

[caasland]

I've used both on our Subaru Outback. I can't recommend them unless you have a specific need for them (track days, overheating, crummy stock rotors, etc).

The slotted+drilled rotors pros:

1. Less expensive than the stockers
2. looked cool
3. better initial bite in the wet
4. stopped just as well as the stockers

The slotted+drilled rotors cons:

1. more brake noise and vibration ("what's wrong with your brakes, man?")
2. odd "thrum" at about 72 mph
3. ate brake pads and warped faster
4. only lasted 15k compared to stockers @ 100k
5. didn't work significantly better than

Granted, I didn't use name-brand (Brembo etc.) parts. My recommendation is to stick to parts significantly like the stock parts unless you have a specific issue the the stock parts you are trying to overcome.

[and I feel your clutch pain ... our A4's rear seal blew at 105k and doused a perfectly good clutch. That cost us $1800 - $900 of which was the flywheel ... arrrgh!]

[veefer800canuck]

For the record, motogp bikes use carbon/carbon brakes.

The only time they use steel rotors is when it's a rain race.

And yes there are benefits to slotted or drilled rotors, on a normal
Commuter car, it's probably not noticeable.

Look at a 1975 CB750's front discs, and a 2012 cbr600's front discs.
If there was no improvement, the 2012 model would still be using solid rotors.

[bomber]

If there was no improvement, the 2012 model would still be using solid rotors.

I would suspect that most riders/drivers will not stress unventilated rotors to the point where they could fee a difference . . . .a great deal like upside down forks . . .better? You bet? Can most riders sustain a pace that will make the improvement noticiable? Not at all.

Short answer for most? Fashion, just like the guy at bike night with the speed hump on his leathers ;-}

[Baz]

I would suspect that most riders/drivers will not stress unventilated rotors to the point where they could fee a difference . . . .a great deal like upside down forks . . .better? You bet? Can most riders sustain a pace that will make the improvement noticiable? Not at all.

Short answer for most? Fashion, just like the guy at bike night with the speed hump on his leathers ;-}

Agree fully!

You will almost always suffer some form of brake growl with slotted or drilled rotors. Unless you are doing track days, not really woth the switch in my mind. I put slotted rotors on my daughters car and saw no performance improvement, and more noise.

[kyzrex]

The slots are not put in it for cooling, but to shave the pads of any residue left on them.  This allows the braking material to give full bite on the rotors and should result in better feel and shorter stopping distance, but much quicker wear in most cases.  The drilling is help cooling by exposing more metal surface to air.  Vented rotors work under the same principal.  So drilled and vented rotors should result in cooler running and more consistent stopping distances, with less fade.  The pads are also a key part of the equation, and should be matched up for the type of driving the vehicle will be used for.  EBC is a very good manufacturer of theses products and will usually do a good job of recommending the product for your driving needs.

Are they worth it?   The extra cost?   For what you want to use the car for, probably.  They will have less tendency to warp and cause vibration when braking.  That may be the best benefit you receive.  If you are used to riding a sportbike, you are probably used to riding (and driving) " the pace ".  If that is the case, you are probably easier on brakes than many drivers and may not need the extra braking power and shorter stopping distances.  


Shopping around can really save you money at times.  The company I used to work for carried EBC pads and rotors for a few years, when they discontinued them they were selling the remaining stock at HUGE discounts.  I sold many sets of pads/rotors to people at a lower cost than for stock quality or even discount quality parts, while we still had them.  Keep in mind that most hard parts sold in a retail store are sold at 100% or even greater markup....accessories sometimes at 2x or 3x cost!  So when they start discounting parts that are discontinued, they can have really good prices, and still be making money.