Power Stop vs PowerSlot brake rotors

[tekdeus]

Anybody using "Power Stop" brand brake rotors? It looks like they only have drilled rotors for the Mk3, but I'm looking for good slotted rotors for my Mk4 Rear TT and front Cobra setup, which they do make. Any good or bad feedback? They are half the price of PowerSlot rotors, and seem to have the same features, and are a US based company.

 

[toy fanatic78]

Anybody using "Power Stop" brand brake rotors? It looks like they only have drilled rotors for the Mk3, but I'm looking for good slotted rotors for my Mk4 Rear TT and front Cobra setup, which they do make. Any good or bad feedback? They are half the price of PowerSlot rotors, and seem to have the same features, and are a US based company.

Have a lot of miles on powerstops in my mk3.I have been told you can't turn drilled rotors though because the holes are chamfered and prone to cracking if you take that away,not sure if that is true.I bought a hone for disc brakes and have them honed on a brake lathe when I change pads,have never had any issues with them whatsoever.

 

[Rennat]

im running powerstops with some porterfield r4s and i loveeeeeee them.


there good, i've had no issues.

 

[toy fanatic78]

im running powerstops with some porterfield r4s and i loveeeeeee them.


there good, i've had no issues.

What pads do you run w/yours?(porterfeilds?)I have powerstop pads on the rear that stop great,and are rotor friendly.I think Axxis pads up front,been so long I forget,but they started to groove my rotors ever so slightly.The discs honed smooth,but I want to try different pads.

 

[Rennat]

i had porterfields on my n/a and when it was all up to spec 100% (as in no air in the lines, and no abs) i would EASILY make my front tires skid because they pads would grip so good.

AND

Powerstop = drilled brembo JUST FYI. they say brembo on TOP of the rotors, if you want proof, i took pics. haha

 

[Poodles]

any crossdrilled rotor is prone to cracking, doesn't matter on the quality.

 

[Rennat]

any crossdrilled rotor is prone to cracking, doesn't matter on the quality.

i talked to a guy who owns a local performance shop that sells the porterfield pads for $59 a set... and he was saying that the slotted and vented rotors he could kill in ONE track day on his track mustang. it wasnt until he upgraded to a full 2 piece rotor with 6 pistons calipers that he was able to not have to change pads between track days.

and he also said that cross drilled and slotted is more of a show thing... only thing he noticed, and so do i, is the initial bite of the rotors because the air has somewhere to go with you compress the pads against the rotors. if you dont care how they look, brembo blanks are good for the money.

 

[tissimo]

i talked to a guy who owns a local performance shop that sells the porterfield pads for $59 a set... and he was saying that the slotted and vented rotors he could kill in ONE track day on his track mustang. it wasnt until he upgraded to a full 2 piece rotor with 6 pistons calipers that he was able to not have to change pads between track days.

and he also said that cross drilled and slotted is more of a show thing... only thing he noticed, and so do i, is the initial bite of the rotors because the air has somewhere to go with you compress the pads against the rotors. if you dont care how they look, brembo blanks are good for the money.

He is correct. A slotted/cross drilled will have a better initial bite though, but with sustained braking the rotor has less mass and more prone to overheating and fading.

 

[Rennat]

a lot depends on the pads also, its 50/50 split for the rotors and pads. i know the porterfield are a carbon/kevlar material, im not sure of any of the other brands and materials.

 

[tekdeus]

Powerstop = drilled brembo JUST FYI. they say brembo on TOP of the rotors, if you want proof, i took pics. haha

Really? I heard that "Power Slot" rotors were also Brembos. I guess both companies do the same thing? But one charges $60 each and the other charges $120?

 

[Rennat]

it wouldnt suprise me...

thats like how i deliver parts now, and im constantly going to car dealers delivering parts for them... so just because you think its a certain brand, its probably not...

and a nice little tip for ya, wire wheel off the hubs where the rotor sits, because if you clean that rust off, the rotor goes on a lot smoother and your not fighting it.

heres my brake job i did.

 

[supradjza80]

slots or cross drilling helps evacuate the gases which build up between the pad and rotor during braking as well...

 

[Keros]

Crossdrilled/slotted rotors are superior to blanks in how they expel heat and deal with fade from the pads. It is true that you sacrifice mass when you drill/slot a rotor, mass that would otherwise take in more heat... but at the same time you gain more surface area to expel that heat into the ambient air. Also, the holes give the gas from the boiling adhesives in the pad somewhere to go... thus effectively raising up the fade temprature of the pad. If Pad A would fade at 700*F on a blank, Pad A may fade at 750*F on a slotted/drilled rotor.

That said, cross drilled rotors are, IMHO, for racing on cars that you intend to replace the rotors on after every race or two. There's cases of the fatigue cracks along the drilled holes propogating across the entire rotor, causing it to break under braking. Street driving and cross drilling aren't the best combination.

For perfromance on the street, slotted is the only way to go. I have PBR ultimate ceramics on Powerslot rotors, and they are awesome so far... 8000km of hard driving and counting. For reliability and longevity, blank rotors make alot of sense.

With good pads, the difference will be small between different rotors, assuming that the rotors and pads were bedded properly. Most fade characteristics lie in the pad, as that the pad is going to heat up and boil long before a giagantic hunk of cast iron will do anything other than be a big chunk of cast iron. More mass in the rotors means the rotor takes more heat from the pads and expels it to the ambient air but more surface area means more area to transmit that heat.

I guess what I'm saying is that the quality of the casting matters more than the amount of machinework done after the chunk of cast iron is shaped into a brake rotor. Slotted, drilled, both, or blank, it's not going to make enough difference to live on for a street car. A cast iron rotor is a cast iron rotor, it'll do it's job if it was cast properly. Any holes that are cut in it after it is cast only serve to weaken its granular structure.

It's all a trade off, there's no free lunch. Slotted rotors tend to kill pads faster.

 

[Rennat]

for what its worth, my dad, has a 99 saab 9-3, its a turbo auto that he daily drives to work every day 120 miles . hes had DRILLED rotors and ebc pads on his car now for well over 5months... he takes his car to over 140mph, and drives like hes 16yrs old sometimes... and with him driving in CA stop and go traffic, where you can be going 80mph and then be STOPPED within seconds, he has no evidence of a crack on his drilled rotors. so drilled is just as street friendly as slotted.

And screw the drilling and the slotting, what you NEED is a rotor that is capable of dissapteing the heat AWAY from the pad so it doesnt fade, which is why a kit like dowards where it uses a bigger rotor, is going to be far superior to anything that we replace on the stock setup.

and btw, a slotted rotor shouldnt kill pads faster... it should have a chamfered edge leading in and out of the slot so that it doesnt create a hot spot from the pad going over the slot.

but like i said in my last post, i talked to a guy who actually races, and when your going too fast, and your brakes just arent big enough, you'll KILL pads and rotors. its only when you step up and get bigger rotors that handle the heat is when you see the biggest gains.

 

[IJ.]

Seen many many Porsche drilled rotors with cracks so I guess they should be buying the magic powerslots that don't crack......:nono:

You are drilling a stress riser into the disc, if the hole was honed and the chamfer micropolished it would improve the cracking situation.

Look at a magnified drilled hole and you'll see it actually tears the material as it drills and this is where the cracks start, Brembo design their blanks to be drilled so will take longer to crack than a blank that's just been drilled.

Brakes are the one place on a performance car where corners should never be cut and parts shouldn't be purchased on price alone...

 

[Clip]

slots or cross drilling helps evacuate the gases which build up between the pad and rotor during braking as well...

i've heard that used to be the case with older pads but now the newer pad materials give off fewer gases during braking.

 

[Poodles]

Bingo, especially once properly bedded in!

Brake systems aren't simple by any means. If the rotor isn't big enough it can't take the heat away from the pad, so the heat goes somewhere else...like into the caliper. Caliper gets hot because it's small and can't disipate the heat, heat goes to the brake fluid. Fluid boils and you have turned the system from a hydraulic system into a pneumatic system. Thing is, fluids don't compress, but gasses do and your brakes are all but worthless at this point.

As IJ mentioned, brakes aren't a place to be cheap in any way. I've personally seen cracked crossdrilled rotors enough times to never run them. While slotted rotors don't crack as easily, they still need to be inspected as they can still crack. Crossdrilling has it's places (namely the same reason as the petal rotors on sportbikes, to increase surface area for cooling), but in most applications it's for looks and nothing more.

NASCAR uses slots, and F1 cars don't have crossdrilled or slots, just an FYI...

 

[figgie]

slots or cross drilling helps evacuate the gases which build up between the pad and rotor during braking as well...

Sorry

Perhaps back in the 70's. Todays pads don't do any of that nonesense anymore.

plane physics.

More mass. More heat absorbotion and in breaking that is a GOOD thing as the brakes are basically a huge heatsink.