Hi, ​​so I own a 2015 Q40S and I've been looking to get my first new set of rotors and brake pads. I'm not too positive about what types to get, as I've been getting mixed suggestions from friends, family, and websites lol. I use the car as a daily driver so no crazy track use or anything like that but I do like to have my fun so there are some times where I'm braking harder than normal. I'm not too sure what's best whether it be drilled, slotted, drilled and slotted, or just sticking with plain smooth rotors but from what I've read and heard it seems like drilled rotors can wear unevenly and crack, slotted wears brake pads faster, and the cross of the two just makes even more weak points. Maybe what I've read and heard is exaggerated but I just wanna make sure I'm not going with a poor choice. I also want to add that I'm not trying to go crazy with the cost, just something better than the stock rotors and pads.

 

Not sure if it was just coincidental, but on every vehicle that I've had, every combination of drilled / slotted rotors that I have tried in the past developed braking vibrations within several months. This included PowerStop kits and even premium StopTech rotors. After much research, I gathered that standard blank rotors are best for general street use, so I began using those. No issues at all. On my recent sport brake upgrade on my '12 xS, I opted to use Stoptech blank rotors with Akebono pads. Excellent, smooth performance. While the drilled / slotted combinations do look better, I noticed no improvement in braking on any of my vehicles. Again, I do not run my car on the track, so I cannot comment as to performance advantages under those circumstances - my G is just a basic commuter car.

On my previous IS350, I took a chance on some plain Bosch rotors from my local auto parts store. The performance surprised me - very smooth, no noise, and the price was very reasonable - about $35 for each front side if I recall correctly.

Welcome to the forum.

 

I'm going to write the opposite of the above. The sport package at least for brakes have a tendency to build up pad deposits. These pad deposits can make it where it feels like the rotor is warped. Now, some people will tell you to just cycle the brakes at a high speed to low speed three to four times in a row and that get rid of the pad deposits. It never worked for me. After the third turn on the OEM rotors, I gave up and bought this:

https://www.knsbrakes.com/c/car-seri...-+Single+Rotor

Haven't had a single problem since. They are a notch louder than stock due to the grooves in the rotors, but unlike most, I did not buy them for aesthetics. I bought them to stop the damn pad deposits from building up. And they've done just that.

Food for thought.

 

I have the same DBA rotors as ryanwhite74115 except mine are slotted and drilled. Yes, I wanted the extra "bling" factor. Paired with Hawk HPS 5.0 pads and after approx. 3+ years and a few panic stops (damn clueless tourists) I have had ZERO issues with this setup.

The OEM rotors were always a hassle for me. As such, I would never use OEM again.

In the end, it all comes down to preference, driving style, and budget.

 

Those DBA rotors look nice. I really like that non-directional slot pattern.



For anyone who's counting... that's at least two tourists rants, LOL

Get off my lawn.

 

Knowing part function usually helps me with a decision.

Rotors are drilled for weight reduction. There are some benefits to this. But you're also reducing surface area. Since the potential and kinetic energy of the vehicle remains the same (minus the weight of the iron that's been drilled out), you're using LESS surface area to stop virtually the SAME vehicle weight. So...a drilled rotor will typically run hotter. You want a pad compound meant to work together with this type of rotor.


Slots...idk. They pull air in or pump it out or something. Who tf knows.

Blank rotors are slightly heavier. But will provide the largest surface area.

For a street car...it doesn't really matter what rotor you choose as long as it uses decent metallurgy and machining. Pick whatever you want.

I find that obsessing about rotor selection to prevent brake pulsation is the wrong way to go about it.

You're almost surely not warping rotors via heat. Look up the softening temperature of iron. Then look up the MOT (max operating temp) and Mu of your pads. Do a little math. Or just take my word for it.

Brake pulsation happens because the pad smears on the rotor surface unevenly. It creates hard spots on the rotor while it does this. So its pretty much permanently made its mark.

Choose better PADS.

Retail grade Ceramic pads are the worst offenders. OEM grade ceramics do a little better. Specialized ceramic pads are rare...and expensive...but they do work.

Retail and OEM grade Semi metallics OR performance grade organics do a much better job at preventing smear. But in comparison to ceramics. ..they're more dusty. Some are noisy, most are not. And they do tend to wear rotors slightly more than ceramics - you'll likely have to change rotors when you change pads. However, the performance (apples to apples) is generally much better than a ceramic pad.

Pick a fairly agressive pad compound. Stoptech 309 or 308 are good examples. 308 is better suited to purely street use. 309's are an "enthusiast" pad.

They'll both dust more than ceramics. This is really only an issue for virtually impossible climates where the wheels get dirty but the car stays clean. In the real world...if my wheels are dirty...the whole car probably needs a wash too. So who cares?

If I lived in CA...with perfect weather and perfect driving roads...and I just got done enjoying tf out of my goodass brakes...I also wouldn't be obsessed with some dust on my stupid wheels. I don't owe those wheels anything.

But that's my opinion.

 

I have Akebono Premiums and Hawk Rotors. I got the hawks for 65 each OTD, don't think they are available anymore. I have never had a problem with Drilled Rotors, but wouldn't recommend for a car being tracked. I kinda wish I had done the Z1 2 piece, they were under 500 back when I was looking. I have had my rotors going on 4 years now. No issues. I have Type 200 ATE Fluid. Great bang for buck.