Slotted or cross drilled

[DenverQ]

Ok I got my rotors today and i opened the box and to my dissapointment i found slotted rotors. i ordered cross drilled so heres my delima do I stick with the slotted or send those back and wait another week for my cross drilled. I would ahve liked to have finished my project on friday, I can if I keep the slotted but if the consensus is to switch then ill have to wait.

ok guys let me know what you all think

[maxnix]

Slotted rotors lose their ability to slough gas as they wear since the depth of the slot decreases with wear.

On the other hand, improperly drilled rotors can have stress fractures where they are drilled and shatter when they are used aggressively. I understand some rotors have the holes cast in them to avoid this problem.

I am sure the slotted rotor users will chime-in to give you a better appraisal of their performance. I have only had "drilled", but not on a Q.

[PalmerWMD]

I have drilled Brembos from Stillen and Like them a lot .They hum a bit under hard braking but I don't mind.

There is much to be said however for slotted rotors and there is a school of thought that prefers them over drilled.

Drilled looks a bit cooler, cuz the holes are visible to most, but I suspect slotted are at least as functional and are likely to avoid the cracking issues that plague some cross-drilled.

If the visiual effects of having drilled are a positive for you ((I admit they are for me:oface ) you may want to get your drilled ones.

Functionality wise, what you have is at least as good, and better according to some.

Fred...

[DenverQ]

So let me get this straight im really not loosing any performance or functionality going with the slotted? I would really like to have the car ready to go this weekend but if I have to wait then I will. I also noticed the new rotors are heavier, maybe its just me anyone else have this issue? I have Power Slot rotors

[PalmerWMD]

Heavier is a good thing, because you have more of a heat sink.

As for functionality, there are two differnt schools of thought, one prefers slotted ,the other drilled.

I believe the slotted are at least (!) the equal of the drilled in fuctionality and they are also likely to be stronger than a drilled set.

Fred...

[DenverQ]

Thanks alot Fred!!!!! I think im gonna give them a try if I dont like them, as much as I drive i shoulnt have a problem next year getting the cross drilled LOL. So after I give them a good work out this weekend alon with the new suspension ill let you all know how I like them

[DenverQ]

Well Ive been doing some reading on the powerstop site and they say that the cross drilled run 150 degrees cooler and the jist I got was that cross drilled were better. Awe man now do I suck it up or b**** and wait another week to get all my stuff. Man doin stuff yourself is hard because everyone else does their job half a**. Sorry for the vent

[maxnix]

I say suck it up and ride the bike while the weather is good. The Q will just be that much more perfect when you get it back together yourself. I really like cast "drilled" rotors as opposed to true drilled. And there is less variance caused by wear.

[Mayhem_J30]

Well Ive been doing some reading on the powerstop site and they say that the cross drilled run 150 degrees cooler and the jist I got was that cross drilled were better. Awe man now do I suck it up or b**** and wait another week to get all my stuff. Man doin stuff yourself is hard because everyone else does their job half a**. Sorry for the vent

Put on the ones you got and get some wear on them. Then call later and tell them that they sent you the wrong ones but you didn't notice it until they were already installed. Maybe you'll get to keep both.

[EWT]

Heavier is a good thing, because you have more of a heat sink.

As for functionality, there are two differnt schools of thought, one prefers slotted ,the other drilled.

I believe the slotted are at least (!) the equal of the drilled in fuctionality and they are also likely to be stronger than a drilled set.

Fred...

Don't forget the school of thought that advocates good old undrilled and unslotted rotors because they work just as well, and aren't as prone to cracking.

[Q45tech]

Never seen any PowerStop drilled that cracked on a J/Q/G and we have installed over 200 sets in 5 years. Have seen some popular other brands of drilled rotors that have cracked [way too many vent holes and non directional].

Watch out thinking that rotor temperature is the most important , it is the pads themselves that fade and change properties with heat.

Drilled relief holes into the center vent is important to help give water somewhere else to go in cold/warm rain.......a single rotation to dry is 6.8 feet you lose.

Measure/ calculated the areas of the holes under brake pads to see the lost swept area......good ones like power stop have less than 5% area loss yet are heavier so the mass is equal to oem ...weigh and compare.

[EWT]

Never seen any PowerStop drilled that cracked on a J/Q/G and we have installed over 200 sets in 5 years. Have seen some popular other brands of drilled rotors that have cracked [way too many vent holes and non directional].

We've had this same discussion before, but I have seen them crack on other cars, although they are a lot less prone to cracking than drilled rotors, and probably won't crack with street use. Introducing stress risers into brake rotors just isn't a good idea though IMO. If you want to upgrade your brakes, start with better pads, then go to bigger rotors/calipers if better pads alone aren't sufficient. Also, change the brake fluid out with a good fluid like Valvoline Synthetic at least annually.