Rotors-slotted or cross drilled

[Madman]

im in the market for new rotors, suprise suprise. any way, i am wondering if any one has an opinion about which are better, slotted, cross drilled, or slotted and cross drilled. or flat (just for the poll).


keep in mind that if i purchase cross drilled, the prosses will be part of the original manufacturing and not drill afterward (if they dont make them that way for ga's, i want no part in it)

[matts]

i voted for slotted. i just think they're more durable than cross drilled. cross drilled are better if you're racing your car a bunch, plus they look good. cross drilled/slotted look even better on the coolness scale. i really think it's a matter of opinion on which you go with. i was told that the cross drilled would crack around the holes on a daily driver, but others say they won't. i don't know. i have slotted on my truck and i can tell a difference in braking, but i also put stainless lines on too at the same time.

[CopMagnet5oh]

the slotted ones would eat more pads, and they dont cool off the brakes as the cross drilled ones do, as air goes through the holes to the vents and back. the slotted ones are only better for hardcore road course racing when the dust from the brakes get trapped in these slots and theres less grabage between pads and rotor, i have had stock mustang GT brakes with cross drilled and slotted rotors before and now i bought new 2003 cobra calipers with 2 pistons and 13" cross drilled rotors.

but if you're not racing at high speeds and long distance i wouldnt spend money on either. get stock replacement.

ps. the material of cross drilled and slotted ones is the same, and it is way stronger than stock replacement.
http://images4.fotki.com/v47/free/d042b/1/135890/500523/brakeswheel-or.jpg

for reference the wheel is 18" and rotor is 13" in diameter

[Madman]

ps. the material of cross drilled and slotted ones is the same, and it is way stronger than stock replacement.


Thats why i dont want stock replacements. gm makes cheap rotors, i have witnessed this in many vehicles. they tend to warp. and in the ga's, mine are warping every 20000miles (maybe less) with pleanty of brake pad left.

[matts]

my slotted rotors don't eat pads very quick. they've been on there about a year and i haven't had to replace pads yet. and i drive fast and do a lot of in town driving

[CopMagnet5oh]

you dont take advantage of having slotted rotors tho, you're only benefit from better material they're made of. if you got cross drilled and drove hard you would make a good use of your money.

i hope i dont offend anybody

[BBT]

Hmmmmmmm....at least one manufacturer (Power Slot I think) recommends slotted for street cars, and cross-drilled for racing, precisely because of the cracking issue. Of course, they may only be talking about their own rotors, and not in general. I'd have to check into it.

They also recommend an upgrade in pads at the same time, no surprise there.

[matts]

that's what i heard when i got mine. and that's probably the only reason i didn't go with drilled. i didn't want to spend $200 every six months when they crack. if i had a car that was strictly off road racing (or on road racing for that matter lol) i would go with drilled. but i really don't think that drilled rotors would hold up to the weight of my truck in daily driving conditions.

you didn't offend me :). i like arguments like this as long as they don't turn ugly

[eblend]

i got cross drilled rotors, they used to be prone to cracking, but now many come with shampering (i have no idea how to spell that, kinda like countersinking around the holes) which reduces the cracking issue a HUGE DEAL! I love mine, they are hella sweet, and they sound hella sweet when breaking, kinda like a jet taking off :)

[tenspeed]

I'm impressed that you know that the countersink around a hole has a special name! It's chamfer.

I voted for no holes or slots. I think that the machining weakens the rotor and is not necessary on the street. It does look cool with aftermarket wheels but not cool enough to buy new rotors every year.

[CopMagnet5oh]

where do u guys buy your rotors that u break them driving a GA ? i have used my cross drilled for 2 years now driving hard breaking almost from 145mph-0 and racing in the summer and nothing happens to them. if u get a plain rotor and then take it to the machine shop to make holes thats going to be crap, but if you buy good aftermarket brakes that are done right they would be much stronger than stock,theres special heat treatment they do when manufacture these kinds of products, I never had a problem with cracking or warping.

[Antalive[DM]]

Well what company do you use? At this moment i only really really trust BREMO.

[CopMagnet5oh]

the rotors i have now are made by brembo, and they're great, they're the ones in that pic i posted above.

[Antalive[DM]]

Yeah See!!! it just depends who you look at and how much you will spend. lol

[matts]

lol. brembo is some of the best brakes on the planet. of course they're going to last. but most people (me excluded) buys the cheaper version of something to save money.

[Antalive[DM]]

ENOUNGH said lol :rofl: :lol:

[jayhawk]

Heres a neat fact on why performance rotors are either slotted or drilled. When you rail on the brakes and they get heated to a high temp., a hot gas occurs between the brake pad and the rotor, causing brake fade. Having rotors that are drilled or slotted helps expel the hot gas. Neat, huh?

[CopMagnet5oh]

that goes more for drilled, the slots help trap all the dust particles of brake pad and other crap that is between the rotor and the pad to make sure it doest go back in-between which reduces slipperage and improves stopping power.

[Antalive[DM]]

:agree:

[sunrunner_pei]

I had Powerslots on my '99, and they were be far the best rotors I ever used. I'll admit, however, that I've never tried drilled rotors. I won't get into the debate of slots or drilled, just wanted to share my own personal experience after I had more than 60,000 KM on my set of Powerslots and Performance Friction Carbon Metallic pads and they were still going stong and stopping my car handily.

[BBT]

Anybody got any independent statistical information on the differences between the 3 types of rotors? So far, it appears that everybody is giving anecdotal evidence, not hard facts supported by anything other than personal experience. Somebody living in dry sunny Arizona may have great experience with his rotors but he isn't operating in the weather extremes I would be. His choice may very well fail dismally here. And vice versa.

I'd like to see something that demonstrates the performance differences between them, as well as numbers indicating some kind of expected life-expectancy of the components.

[CopMagnet5oh]

ok, i dunno where to find such info, but look at porsches, mercedes, and other big performance carmakers, what do they use on their cars ? - just cross-drilled rotors. these cars are meant to be a daily drivers for anybody.

performance competition like Saleen use slotted rotors because they are meant to be used for high speed competition driving.

[matts]

but for arguments sake. when rich people have a porsche sitting in the garage they tend to not get it out in the snow and ice. and how many times have you raced on a wet or snowy road? i'm not trying to agree or disagree with you. but BBT is just wanting to look at it from all angles before making a purchase. i don't blame him

[CopMagnet5oh]

actually there is a lot of porsche enthusiasts ( i dunno if spelled it right ) who race in snow, about me - no , my car has never seen snow.

but i honestly i dont think getting a better brakes will make it worse in any condition or weather would affect the brakes, if thats what you're saying.

maybe we took the thread in a little different direction than it was meant to be, but i'm expressing my thoughts here :) abouit the question that was asked.

i'll try to find some comparison charts and post it on here.

[matts]

well if they've got money coming out their ass and wanna take their porsche out and play in the snow........have at it.

sometimes when you buy something that's better it doesn't always mean it's better for ALL conditions. like putting a tunnel ram intake on your car. yeah, it's gonna give you awesome numbers over what you had, but you couldn't hardly drive it daily because of the lack of low rpm torque. and drag racing rear end gears are made just for that......drag racing. theoretically you'd think that something that is made to withstand drag racing would be more than enough for the street, but not the case. i don't think brakes would make a difference either.

here's a scenario. let's say you put cross drilled rotors on your car. you go out into the ice and snow and ice get's packed into the holes. (let's say that heat and friction didn't melt it easily). then you're trying to stop and instead of metal your pads are grabbing ice. have you ever tried to grab something slippery and get it to stop? not the easiest thing to do

[BBT]

Racing experiences weren't the intent of my query. I'm more interested in the day-to-day grind that we put our cars through. Commuting to work, stop and go traffic, go get groceries, etc. And then do that in all weather, all temparatures with the salt, snow, ice, sand, grit, slush, crud and grime that comes from all of that. You know, the REAL world.

Not saying that copmagnet doesn't have a point. He does. But I drive a Grand Am every day, not a Porsche (although I'd love to try one for a year! :D).

I did some checking around, and this discussion (slotted vs cross-drilled vs slotted AND drilled) comes up a lot. There seems to be the same divisions of opinions on those boards as well. Maybe it is time some car magazine do some comparison and long-term testing.

[sunrunner_pei]

Originally posted by BBT
Racing experiences weren't the intent of my query. I'm more interested in the day-to-day grind that we put our cars through. Commuting to work, stop and go traffic, go get groceries, etc. And then do that in all weather, all temparatures with the salt, snow, ice, sand, grit, slush, crud and grime that comes from all of that. You know, the REAL world.

That is why I posted what I did. I don't know if you're ever going to get good hard data, because there are too many variables involved. Brake pads have as much to do with braking performance and life of your rotors as the rotors themselves, IMO.

[Madman]

the poll speaks for itself. gonna go with slotted. thats what i was thinking originaly. found a pair online for $161 w/ free shipping, not to bad. no for the brake pads, any suggestions on brands?