Whats the difference between crossdrilled and slotted brakes?

[KPC1.8TQuat]

I'm looking at this kit from ecstuning.com

Stage 2

What is the difference in selecting rotors that are crossdrilled/slotted or just slotted. There is almost no difference in price. Is one better than the other?

[MOFSTEEL]

Crossdrilled/slotted



slotted



IMO crossdrilled rotors have a tendency to crack.

[Maverick]

cross drilled rotors may be easier to crack.
slotted rotors will give you more the hissing noise.

[KPC1.8TQuat]

cross drilled rotors may be easier to crack.
slotted rotors will give you more the hissing noise.

Hissing noise. You mean when they overheat?

[Maverick]

no, it's a constant noise that you hear while driving if you dont have music on loud enough.

you will hear it when you put on the slotted rotors. sounds like something is always rubbing

[kwik_shift]

Like^^^ cross drilled tend to crack over slotted but thats under extreme conditions. If your just upgrading get the ones you like better.

[KPC1.8TQuat]

Alright, well I don't track the car or even beat on her. I guess I will go with slotted and drilled then.

Thanks.

[[email protected]]

You should go with blank flat face rotors if you are using them for the street.

You need all the metal you can get to help with heat dissipation.

[ILikeBigBrakes]

I have the ECS stage 4s and don't get hardly any noise and rare squicking

[AudiA4Turbo22]

You should go with blank flat face rotors if you are using them for the street.

You need all the metal you can get to help with heat dissipation.

very true, also cross drilled/slotted will be harder on ur pads. Buddy of mine tracked his car once with Zimmerman's, and they were warped by the end.

[KPC1.8TQuat]

So you guys are saying not to worry about the crossdrilled/slotted, and just go with slotted?

[EUROaleksey]

they are saying get a flat surface ones....!

[KPC1.8TQuat]

they are saying get a flat surface ones....!

Well, out of the options I gave them, all the rotors come with crossdrilled/slotted or slotted. Since a flat rotor isn't an option I assume they meant just slotted.

But hey, thanks for contributing.

[AudiA4Turbo22]

get slotted/ cross drilled go all the way if those are ur choices. Heck i would.

[[email protected]]

Well, out of the options I gave them, all the rotors come with crossdrilled/slotted or slotted. Since a flat rotor isn't an option I assume they meant just slotted.

But hey, thanks for contributing.

I gave the best option that wasn't listed.

If you have to chose from your options then go with slotted.

[B6driver]

are you just using it for street? then it wont really matter... you wont stress them enough to crack, no need for slots, or cross drilling... e.g. it doesnt matter... the only factor here would be pad wear.

[CyberPMG]

Slotted will result in faster pad wear (slots are designed to maintain a clean contact surface between the pad and the rotor). You only need cross drilled if you need to reduce weight and cool down the rotors faster.

The downside of cross drilled rotors is the chance for heat stress cracks because the holes are literally drilled out of the rotor. Those who have it on cars that only get street use are only using it for show. Driving around on the streets doesn't build up the heat in the brakes to warrant any holes.

More than likely, your rotors are mostly cool until needed for emergency. At that point, you need as much surface contact to generate as much friction as possible to bring the car to a stop. Like Winston said, the best street solution is a simple plain rotor with no slots and no cross drilled holes. The next step up would be slotted rotors (good if you do a lot of spirited driving and/or track time).

[Papachristou]

IMO crossdrilled rotors have a tendency to crack.

this is a popular myth. the first old time cross drilled rotors did have a tendancy to crack more because they werent drilled with the vanes. new cross drilled rotors are drilled in certain locations and are usually chamfered to to further reduce cracking.

porsche, vettes, vipers, mercedes and lots of other high end cars and track cars come with drilled rotors from the factory. brembo sells cross drilled almost exclusively. why is that?

[KPC1.8TQuat]

So I guess I need to base my decision on the following...

1) I don't track the car, and I usually drive pretty mellow.
2) The reason for the upgrade is because I'm going GT71r elim.
3) I can't go any bigger than ECS stage 2 because I use 17's for my winter wheels.

Unless someone can recommend a good non-slotted BBK upgrade, then I am going with the ECS stage 2 slotted with porsche boxster 4 piston calipers.

[A4natomical]

Slotted will result in faster pad wear (slots are designed to maintain a clean contact surface between the pad and the rotor). You only need cross drilled if you need to reduce weight and cool down the rotors faster.

The downside of cross drilled rotors is the chance for heat stress cracks because the holes are literally drilled out of the rotor. Those who have it on cars that only get street use are only using it for show. Driving around on the streets doesn't build up the heat in the brakes to warrant any holes.

More than likely, your rotors are mostly cool until needed for emergency. At that point, you need as much surface contact to generate as much friction as possible to bring the car to a stop. Like Winston said, the best street solution is a simple plain rotor with no slots and no cross drilled holes. The next step up would be slotted rotors (good if you do a lot of spirited driving and/or track time).

listen to to him^^^

its all for cooling. they would be overkill for street driving.

[KPC1.8TQuat]

So what rotors are you guys running?

[Papachristou]

i got slotted/CD from ecs but i think next time or on a BBK i will just get slotted..... i got these for looks... had them for 45k of pretty tough driving and they havent cracked at all

just switched to ferodo ds2500 pads and they are a huge improvement over hawks. when they sink in, they drag the car down very quick

[[email protected]]

this is a popular myth. the first old time cross drilled rotors did have a tendancy to crack more because they werent drilled with the vanes. new cross drilled rotors are drilled in certain locations and are usually chamfered to to further reduce cracking.

porsche, vettes, vipers, mercedes and lots of other high end cars and track cars come with drilled rotors from the factory. brembo sells cross drilled almost exclusively. why is that?

Big difference between making a x-drilled rotor at the manufacturing level vs. taking a blank and drilling them afterwards.

Guess which process ECS uses.

[KPC1.8TQuat]

Ok ok ok

What kit would you guys recommend to clear OEM 17" S4 Avus rims?

[ngng]

Ok ok ok

What kit would you guys recommend to clear OEM 17" S4 Avus rims?

i'd reccomend you use the search before posting stupid questions. why did you even post if you don't care what people say? x-drill are more prone to cracking. xdrilled, slotted, dimpled will wear your pads faster.

you're not going to be on the track. use OEM, flat rotors. if you did a search, you'd realize changing your rotors WONT have an effect on your caliper clearance.

[KPC1.8TQuat]

i'd reccomend you use the search before posting stupid questions.

I did use the search feature which pointed me to the different ECS brake setups.

Good contribution to my thread, thanks.

[KPC1.8TQuat]

i got slotted/CD from ecs but i think next time or on a BBK i will just get slotted..... i got these for looks... had them for 45k of pretty tough driving and they havent cracked at all

An example of a helpful post. Personal experience and recommendation.

Thanks.

[Papachristou]

An example of a helpful post. Personal experience and recommendation.

Thanks.

anytime. let me know if u need anything else

[CyberPMG]

A BBK that will fit inside a OEM 17" S4 Avus wheel is the Stoptech 332mm slotted rotor kit. I have this on my car and use those exact same wheels as my winter set.

Since you've expressed more street use (I do track mine), your best solution would be to look into upgrading to some B6 S4 calipers and rotors. The rotor can be a plain rotor or slotted. Go with some good brake pads (Hawk HPS, Ferodo DS2500, etc.) and fresh brake fluid (needs to be flushed out completely every 2 years regardless of miles) with any DOT 4 compliant brand. For a little more, go with Motul 5.1 synthetic which is DOT 4 compliant and offers higher boiling points.

[AudiA4Turbo22]

^^precisely, for the street the most cost effective method is to do a B7 A4/B6 S4 brake upgrade they are the same. U need minimal stuff so not too costly and they'll work great. easy to change too.

[KPC1.8TQuat]

for the street the most cost effective method is to do a B7 A4/B6 S4 brake upgrade

Ok, cool. That is definitely something I will ponder this weekend before I make a BBK purchase.

[mxrz]

I could think of more cost effective ways of increasing unsprung weight with no real benefits.