Drilled rotors came out of autocross, drilled for lightening, not cooling. The problem you get into aftermarket drilled rotors is they are standard rotors that are drilled. There are three issues; one is that you have to design the vanes to accommodate the change in airflow. You want the centrifugal force to primarily suck the air from the hat section of the rotor, and vanes are designed to do that. So when you just drilled into them, it changes that pathway. But the biggest issue that everyone knows of is you need to chamfer the holes to present cracking. While that easy to do on the outside to the two rubbing discs of the rotor, how do you chamfer the hole facing the inside, the vane channels? You don't. If the rotor is designed as a hole vented rotor from the get-go, you can cast in dimples with bumps on the vane cores to deal with that. Another situation is you really want all the mass you can get, so that's really the third of taking a stock rotor and drilling it, as many of the aftermarket situations are.

Grooves to a good job of removing gases and water from between the rotor rubbing surface. The amount of cooling is minimal. Water removal gains you one revolution of the wheels but so does the leading edge of the brake pad, just not as well. Gases are generated under two conditions. When the friction material is green and still needs to carbonize, and when the organics degrade. But having that groove requires you to have a non-compliant or stiff friction material. The grooves with a softer or compliant material just act like a slicing plane. A stiff pad leads to hot-spotting and heat banding on the rotor, so its sort of contradictory situation. I had to block out names.







The other issue that always comes across is if you need to resurface the rotors, not every shop can resurface the rotor with the holes or grooves due to the lathe tooling.

The friction material is always in some state of green. It needs to carbonize at the rubbing surface, but materials with a low or proper percentage of organics will minimize outgassing or fade. This will be tempered in the early use by how much baking the pads had coming out of the pressing operation. At the OE level, long baking is necessary so the potential customer going out on a test drive doesn't get a poor brake feel and a change of mind. In the aftermarket, you can get away with "they are not burnished in yet". For the DIY'er, having an instruction sheet telling him to do the leg work of the expensive baking has the pad manufacturer laughing to the bank.

Grooves will let the gasses from degradation or rapid cooking of the organics to escape. The "always in a green state" comment is that the true friction material against the rotor is a carbonized material, which doesn't happen without temperature. In normal braking, it's only a few thousands of an inch deep, so the process continues throughout the life of the pad. But its a more rapid state with higher workloads, either speed or weight. If it enters that level in a slower fashion, there is no issue, the gasses are moderate. And if the pad has a higher percentage of organics, there's more gas. And different phenolic binders have different resistance to degradation. This is getting way long.

If the manufacturer uses the right organics and in the right percentage for given energy dissipation, there is no fade, no need for grooves. OE most times this is done. Aftermarket, price point fits in big time and reputation is often the key. But the enthusiast can easily overcome well-designed pads with alterations such as larger tires, overloading the truck, ortrailer brakes that don't do there share.

But for someone who has had 30 years in the friction material industry testing everything from a Honda CX to a class 8 truck, I'll choise well design and made friction material with solid surface rotors every day of the week.

 

I went with the ECB Greenstuff 6000 Series pads. I don't know what the previous owner had on but these are notably superior in performance. They're also quite dusty, unfortunately.

https://ebcbrakes.com/product/greenstuff-brake-pads/

 

Did they have that bedding compound on them?
When I had my 2002 Ranger and put the new pads on with new rotors it was a tight fit.
Once the stuff had done it's job they fit much better and stopped well.

 

They are another company that kicks the friction coefficient up, by being more abrasive often.

 

I did HAWK pads and CRYO fronts years ago and they are AWESOME.

I thought about upgrading to larger fronts a while ago for more braking power when towing my heavy trailer but decided against it.

 

IIRC they did have the red stuff, but that's a big if. I do remember them being a tight fit though.

 

It's way easier to just up the friction then install "bigger brakes". But as I said other times, you need to do that with both axles. The Superdutys were designed around having the same friction material on both the front and rear brakes.

Cryo rotors and not necessarily needed. They increase the hardness of the surface which makes them less prone to off-brake wear, less chance of pulsation. But that sacrifices cold braking which is abrasive wear. So for the same friction material, you lose effectiveness. The Halk LTS/Cryo combination addresses that to some extent as the pads have a slightly higher mu. It's why every cryo rotor supplier has a rotor/pad combo. You put cryo rotors with stock material and you lose effectiveness. It's just better to have rotors that have a low installed runout to address the pulsation issue.

 

I will do by my own my brake system next winter. Overhaul everything, put new pistons in the calipers with lubricant, not dry like the Raybestos stuff. I will face-turn the rotors on my machine (sorry, don't know the word in english). Which are the best pads to make the brake "bite" properly? I don't care about wear, I prefer to change the pads every 20tsd. miles. It's important for me that the pads brake well because I'm on the road a lot in the mountains with my heavy F350 camper (2006 6,0 DRW 4WD 6,5 metric tons).

 

For the front pads application the Motorcraft BRSD1069 or newer BRSD1631 seem to be good, OEM pads. Hawk Performance makes the Super Duty HB528P.811. EBC brakes makes the Extra Duty ED91777. Powerstop makes the Z36 Truck & Tow Z36-1069. Good luck, Russ

 

Just returned from getting new tires and the brake pads still show about 60% remaining...rotors look great. This truck just turned 163,000 miles, so I guess I will hold off till next year to do the brakes...maybe!

 

The thing about performance rotors that is rarely taken into consideration is the loss of surface area by removing material (holes/slots). We tested all sorts of rotors while racing and found slotted was preferred the way to go in high heat situations, not for heat, not for weight but to keep the pads clean and not glazed over. That said SD trucks are different animal and I know nothing

I'm due for front pads soon and was thinking about EBC Yellows but sounds like Motorcraft has the best replacement market for these.

 

Just keep in mind that Motorcraft has two graded. The one they sell to who ever walks inand asked for pads.
The other one you have to ask for. They are the serve duty (HD) ones.