Grinding noise coming from Powerslots?!

[PontiacGT2K]

When I brake between 70mph-30mph I hear a loud grinding noise. It sounds like metal-metal grinding (yeah I know it's two metal surfaces) but it's a very very loud noise. I hear it over my system, and my system is loud...

I don't really get a vibrating from the rotors like they're warped...but you can tell something's messed up. Is it pads? I've had the powerslots/ebc greenstuff pads for 4k miles now, and I've had this noise for about 500 miles....Any help is greatly appreciated!

[VaGT]

Do you still have pad material left? Any chance you are hard on the brakes and chewed through the pads already?

Don't forget that your inside pad wears faster.

[PontiacGT2K]

I may very well have gone through pads already. There's been about 5 times I can think of where I'd be racing and brake hard from 130-30....just because we were out of road or what not. I brake hard in general...hence why I got a "performance" setup. I'll check out pads today, thanks!

[ryGT1]

I can tell you with my powerslots I get a grinding noise as well. That's normal, but it shouldn't be that loud, I can hear it a little with the stereo on if I'm listening for it.

The reason it started doing it after 500 miles is mostle due to rotor and pad "break-in".

But, if it's REALLY loud then I would say something is up.

[badassgrandam99]

...i've had my powerslots on for over 50k miles now and i don't have the sound that you and ry have... i would think it could be the pads, but if it isn't then i'd go somewhere to get them checked out cuz you don't want to risk having no brakes

[AMRAAM4]

there is something caught between your pad and the rotor.

[ryGT1]

Originally posted by AMRAAM4
there is something caught between your pad and the rotor.

There's nothing between my rotors and pads but air.

[AMRAAM4]

Originally posted by ryGT1
There's nothing between my rotors and pads but air.

HUh?

Do you have a grinding noise?

[ryGT1]

Yep, since day one with my powerslots

[AMRAAM4]

well it seems that Pontiacs is much louder than mosts, so I was replying that he could have some small particle between the pad an drotor, hence when he hits the brakes it grinds like a mofo.

If you have nothing, then it's your type of brake pads, or the rotors surface was not smoothed enough. That would be my guess.

[ryGT1]

The powerslot was designed for one thing, the shave the face of your breakpads to give you a clean breaking surface all the time. That's why there is so much break dust, and thats why they grind.

I've heard them on three different types of cars, and they all had the grinding noise, some was worse than other due to the pads... but the onse with the EBC pads weren't as bad...

[AMRAAM4]

Originally posted by ryGT1
The powerslot was designed for one thing, the shave the face of your breakpads to give you a clean breaking surface all the time. That's why there is so much break dust, and thats why they grind.

I've heard them on three different types of cars, and they all had the grinding noise, some was worse than other due to the pads... but the onse with the EBC pads weren't as bad...

Are you telling me slotted rotors are designed to "shave" the brake pads???

[PontiacGT2K]

I get a really really loud grinding noise.....it started around 4k miles after install....

[ryGT1]

Originally posted by AMRAAM4
Are you telling me slotted rotors are designed to "shave" the brake pads???


Exactly

[AMRAAM4]

Originally posted by ryGT1
Exactly

Slotted rotors provide venting of hot gases created by your break pads during hard braking. They also lessen the chance of rotors warping from lower temps. Slotted rotors are a second alternative to cross-drilled rotors that were previously known to crack under high temps due to their holes being drilled too large. Since then they have been designed much better. Actually, the shaving aspect you mention is a drawback of slotted rotors...why would you want to shave down your pads quickly???

[UNCTYPE-S]

well this is just great. i was planning on getting powerslots or crossdrilled really soon and now i dont know what to do. whats the best rotor?

[AMRAAM4]

UNC, go with cross-drilled if you like them. Unless you are a hardcore driver that does a lot of mileage or beats the snot out of them, you don't have to worry about cross-drilled fracturing. Just makre sure they are a reputable brand.

This is why MFuller doesn't like cross-drilled rotors, but he has admitted that he is paranoid :p But he does autoX a lot so it is understandable.

Me, for my other car, I am buying cross-drilled and slotted Brembro's

[UNCTYPE-S]

well ever since i started my new job like 4 months ago, my oem rotors were fine until im all highway now. i basically want something durable for all highway driving that i do now. should i still go with those.

[AMRAAM4]

if you don't want any slots or holes I am sure Brembo sells OEM replacements. That way you have the OEM look, but not the crap GM price and quality.

[UNCTYPE-S]

i dont care if their holes, slashes, cuts, cross drilled, or anything like that, i just want them to work and never have to worry about them. i dont care what they look like as long as they work.

[ryGT1]

Originally posted by AMRAAM4
Slotted rotors provide venting of hot gases created by your break pads during hard braking. They also lessen the chance of rotors warping from lower temps. Slotted rotors are a second alternative to cross-drilled rotors that were previously known to crack under high temps due to their holes being drilled too large. Since then they have been designed much better. Actually, the shaving aspect you mention is a drawback of slotted rotors...why would you want to shave down your pads quickly???


Well... i would assume nobody wants to go through break pads fast... but if you want great break performance, you need a clean breaking surface. Which is what the slots are actually designed to do. The fact that the slots vent gas is kinda a myth. They do, but its such a small amount it does very little for the temps of the rotors.

I got the powerslots because I wanted to stop fast... and thats what they do. But they eat pads away over twice as fast, thats the drawback. But, with low-dust kevlar pads (such as the EBC greenstuff) break dust is (almost) non-existant.

Do you need powerslots on a GA, no... do you need cross-drilled rotors on a GA, no. To me, cross-drilled show no gains on a GA, mostly because the car isn't that fast (unless you make them it fast :thumbs: ) and you do some crazy driving where a rotor needs fast cooling. That's why I got the powerslots, because they are a quality rotor, and increase breaking performance all the time. But man, the dust with the pads I have on there now is crazy... can't wait until I get my EBCs.

UNCO808, if you arn't looking for a breaking performance increase, do as AMRAAM says, getting a good quality OEM replacement with good pads would be the best way to go!

[AMRAAM4]

I totally and 100% disagree with you and your info on slotted and/or cross-drilled rotors and the whole shaving the pad, heat is a myth. And I think many other people would as well.

Do some research and you'll find slotting and cross-drilling to specifically talk about heat, surface area, and structural integrity, all having to deal with the rotor and nothing to do with pads shaving away.

[ryGT1]

First of all, I never said heat is a myth. The fact that that slottled rotors vent gas is a myth! Heat is a huge problem with rotors, when you drive fast and break hard, thats a fact. Show me somebody with regular aftermarket rotors that destroyed them from heat with a GA... Well, maybe somebody who tried to do autocross with one... but thats another problem in itself.

A slotted rotor helps to give you a clean breaking surface everytime you break, hence inproving breaking performance. That's a fact. It's also a fact that heat is a problem with rotors under hard driving conditions, which is where cross-drilled rotors can play a huge advantage, but they also have their dissadvantages which you already mentioned.

All I'm saying is for our application, both are not needed. But, to each his own.

[PontiacGT2K]

Bah all I know is the powerslots are great rotors....they brake well in all conditions and will last me a long time. Just don't get why they're grinding!

[ryGT1]

Originally posted by PontiacGT2K
Bah all I know is the powerslots are great rotors....they brake well in all conditions and will last me a long time. Just don't get why they're grinding!


Dont worry! Mine do the same, and so do many other cars i've been in with powerslots. But all within reason... the grinding i'm talking about isn't that loud, but you can hear and feel it. If you feel it's really loud, i would call powerslot.

[n43210]

You know im no pro at any of this stuff but to me its all simple. Factory rotors are crappy but their smooth. Powerslots have long cut out pieces in them and cross-drilled have holes in them. Sorry for the crappy description but as someone else said, thier designed to slice away the pad. Imagine a cd with holes in them. now get a spunge and rub it around. see how the spunge feels bumpy and rough. now imagaine decellerating from 70 mph to 30 in a few seconds. Now can you see why thier is a grinding sound. If you cant see what im saying then maybe im not giving a good enough desciption. Im just getting into the car thing so im still an amateur. later

[AMRAAM4]

JESUS PEOPLE!! THEY ARE NOT DESIGNED TO SLICE AWAY PADS!!!!

That is the stupidest God damn thing I have ever heard in my life!! Can you imagine a race team wanting to change pads during a race, because at those speeds and temps they would tear through them in no time.

IT IS FOR HEAT DISSIPATION...PLAIN AND SIMPLE!!

Whoever told you it was for slicing away pads is a God damn idiot. Plus I would like to see your written information on this characteristic!!

[fishhunter911]

I am with Amraam on this one..... they DO NOT grind away the pad.... as a former Tech I know for a fact they are not designed to "grind" away the pads..... .heat dissipation is the only thing they are made for..... less heat build up in your breaks result in a quicker stopping time... when heat builds up on your breaks it causes a gas build up which in return makes it more difficult for you pads to press against the rotor. the slots and holes help the gas release so there is efficient breaking power.. hence the reason they are called POWERSLOTS........ it is know in cross drilled or slotted rotors that a minimal grinding noise will be heard and is normal. however if you can distinkly hear it over the usual road noise the vehicle has then there is something not right. The rotor may be rough or not balanched properly.... both of these issues can be resovled by removing them and installing another set. As mentioned before.. if you question the fucntionallity of the rotors then call the manufacturer of said rotor.

[ryGT1]

So I guess the people at powerslot are idiots...
ok then

"Heat is the primary cause of ineffective brakes due to fade. There is actually a “boundary layer” of gases that builds up between the pad and rotor surface which inhibits performance. Here’s where Power Slot rotors make a big difference. The exclusive Vac-U-Slots machined into the rotor “wipes” brake pads clean, evacuates gases, and sheds heat. A combination of a “high performance pad” and Power Slot rotors will provide superior reliable braking for virtually all automotive and truck applications, with an upgrade to larger diameter rotors and bigger calipers typically only needed for the most severe competition applications."

from www.powerslot.com

I really like the part where they say the rotor "wipes" the break pad clean.

and calm down.. I don't know what's worse, the fact that we are arguing over this, or the fact that you're getting ****ed off about it.

[fishhunter911]

Originally posted by ryGT1

I really like the part where they say the rotor "wipes" the break pad clean.


how does "wipe" translate into GRIND....... all it simply does is removes a layer of dust.... somewhere in the neighborhood of less than .0005" that will not cause a grinding effect

[ryGT1]

Originally posted by fishhunter911
how does "wipe" translate into GRIND....... all it simply does is removes a layer of dust.... somewhere in the neighborhood of less than .0005" that will not cause a grinding effect


Good point, grind was the wrong word to use. We just are using that to describe the sound it makes.

So, as a former tech, can you tell me why these rotors eat through pads twice as fast? Also, cause all that additional break dust???

[fishhunter911]

Originally posted by ryGT1
Good point, grind was the wrong word to use. We just are using that to describe the sound it makes.

So, as a former tech, can you tell me why these rotors eat through pads twice as fast? Also, cause all that additional break dust???


I can try to.... as the rotors wipe the pads clean, it does removes some of the pad however not that much, now you have to keep in mind that when using traditional rotors, there is a good amount of heat build up in normal drive and even more under hard breaking. So what this means is everytime you use the breaks there is a build of gas between the pad and the rotor so the effectivness of the pad is diminished. basically the pads doesnt make as firm a contact with the rotor as a cooler pad would... I am not sure if this make sense...basically the more contact that is made the more the pads are used... does that clear it up at all???

[VaGT]

Originally posted by ryGT1


But man, the dust with the pads I have on there now is crazy... can't wait until I get my EBCs.



If your getting the EBC's because you think they won't dust much... you're buying them for the wrong reason. Mine dust like crazy ... even on plain faced rotors.

[PontiacGT2K]

Well it's two flat surfaces hitting eachother. A sponge and a holy cd is a very bad analogy...the sponge expands beyond the surface of the cd allowing it to be cut in pieces. The pad does not actually go past the edge of the rotor, it's grinding against it. It may over time pull some more material off than expected....but it sure as hell doesn't just grind away at pads....

[PontiacGT2K]

Originally posted by VaGT
If your getting the EBC's because you think they won't dust much... you're buying them for the wrong reason. Mine dust like crazy ... even on plain faced rotors.

Mine dust like crazy on the powerslots. People think I've got gunmetal rims....

[AMRAAM4]

Reading powerslots paragraph, people are taking their intention the wrong way...which has already been clarified. They "clean" the pad of the GASES which cause heat buildup, not "clean" the pad by literally shaving pad material away.



P.S. Meetings that involve all military services tend to make you want to jump out of really tall buildings :duh: :crying:

[fishhunter911]

Originally posted by AMRAAM4

P.S. Meetings that involve all military services tend to make you want to jump out of really tall buildings :duh: :crying:

O know a few you can jump from, I'll even clean uip the mess :cheers:

[safemode]

wonder why they decided on such wide "vac-u-slots" were necessary instead of slightly more but thinner ones...which would probably lead to a more uniform and lower volume sounding break. Maybe that much gas is made in racecars when they break hard...? I guess this is just an example of a type of break people are buying for looks when in fact it's a completly functionally designed break with no consideration for "grinding sounds" because it's made for cars that care about stopping before they hit the wall and not turning heads at traffic intersections.

I think more and thinner slots would do the trick for the normal use but street/racer person wants, but it's probably not a large enough niche to make money off of for these people. It's too bad you cant just take high performance flat breaks, and drill-press some slots into them. Would hate to be the test pilot.