I could really use some help here. I have a '99 GS, and I just bought some wicked rotors from raceconcepts.net. They are xdrilled and slotted. After I put them on the car, I realized that they were directional. doh. ;( It was late, so I didn't want to mess with them, but the front ones are swapped sides, which means the slots hit the pads outside to inside. Does this really make a difference? Will I lose some performance, or even worse, will this mess up my rotors? I don't know a great deal about brakes, but just looking at them, it would stand to reason that since I have them on backwards, it may push the hot gasses TOWARD the center of the rotor rather than AWAY like slots are supposed to, but other than that, I can't see what the harm would be in leaving them like this for a week or so. Can someone who knows tell me for sure, the consequences of having these fronts on backwards? Thanks for your help and time.

snuFaluFagus

I would take them off and turn them around. I dont think that they will ruin the rotors but, if you think about it they were designed for a specific direction in order to work properly. also the veins on the inside were designed to pump air towards the out side of the rotor. you might have a heat problem ,which leads to a warpage problem that is associated with cross drilled rotors anyway. So if i were you I would switch them around.

Yes, they are directional for a reason. At the very least, they will not work as well. At the worst, you could throw your pads (depending on the car and rotors, I'm sure it's happened on race cars) I don't know how likely that is with our car, but I'd set them the right way.

are the vanes directional? the direction of the vanes is a lot more important than the slots. i forget who - the guy with the hella nice brake system on the board - has some rotors that have the slots going the way yours are. however his vanes go the opposite way from the slots so that's why he has them on like that. this ensures that the vanes direct gases away from the center of the rotor. he'll prolly post here. he's the one with the willwood calipers i believe. it was something crazy like a 6 piston caliper or soething. but yea check which way the vanes go. they might even be non-directional in which case it's not that big a deal.

-marc

='95 RS 5spd Red=
Matrix CAI
A'pexi Turbo N1
Hanabi 8000k HID
SPAL Deluxe Power Windows
Nakayama GT5 17's
Ractive STB
GSX Calipers
AEM Rotors

255 is fricken short

ya that's me.

actually, i do not think the direction of slotting is important. it is the direction of the internal vanes. On a stock rotor the vanes are non directional. i think the slots going from top hitting the pad first is the way to go. this will bring the brake dust and gasses toward the center AWAY from the caliper the wilwoods I have heve directionally vaned rotors so the rotor itself acts like a fan. it pulls air from the center of the disk outwards, when the slots bring the gasses ad dust towards the center away from the caliper. The slotting direction I believe does not matter. its the vanes that matter. but if you do not have directionally vaned rotors then it shouldn't matter what direction you have them on. the only thing i would see as a problem if you were to want to swap them is that you would have to get them turned before switching them because they would be broken in to the current sides.

Lates
James

I'm thinking the same thing as James. The internal vains are radial, not spiraled - so they are not directional. However, the slots could make some kind of minute difference. And I think that the only way it makes a difference is if the break dust is swept inward or outward. Though break dust will hardly do something just that simple in a spinning wheel, with air circulating around - the dust is going to get everywhere anyway. However I do thing that James way will lead to slightly cleaner caliper. Why? Because I notice that show cars almost always have it in the same way as James. But a lot of performance cars have exactly the opposite.

cool, thanks for all the advice. i flipped them after only half a day driving EASILY on the new brakes and pads. i believe the internal vanes are non-directional (because i got them from raceconcepts.net--brembo blanks with slots and drill holes added), but i had them turned the way i see most everyone else has them, with slots hitting the pad closest to the middle first, then going out. i understand that flipping them might drive dust inward, away from the caliper, but won't i also be driving heat inward, toward the center of the rotor, and isn't that a bad thing? all i know is that i have a HEAVY car (big stereo, no weight-reductions whatsoever) considering the wimpy size of our rotors, and i've heard that stock rotors on our cars warp easily because of the intense heat caused by this, so i would think the most important thing would be driving heat out at all costs. plus, i have performance friction pads which i'm told work great, but cause a lot of extra heat because of the compound they're made from.

it's so hard to choose... everyone has their own way...






looks like 2 votes for, 2 against... :P

i even emailed the guy i bought my brakes from, from raceconcepts.net, and he couldn't give me the straight answer.

even if i put them back the original way, slots hitting the pads from outside to in, and this does drive dust toward the center of the rotor, wouldn't that dust build/up around the middle of the rotor? and if it won't buildup, then where does the dust actually go that's being driven to the center? if it doesn't stick, it goes somewhere, right? maybe just out all over the wheels? seems to me if you drive it outward like i have them now, at least it'll stick deep inside the wheels somewhere ya won't see it. :thumbsup oh well, heat is my biggest concern, so i think i made the right call. please let me know if you think otherwise. brakes are a LOT more complicated than i thought... :+ thanks a lot for your help and time.

snuFaluFagus

so according to your guyz' pix I have mine the wrong way? I've had mine this way for awhile and it seems to work well. it looks kinda goofy the other direction O_o

Yes those rotors are glowing

nooooo, yours aren't the wrong way! yours are the same way mine are now. in the pix i showed, 2 went one way, and 2 went the other way. bottom line is, the internal vanes you can't even see should determine which way you put your rotors on, because diff rotors are designed for diff things, and sometimes the internal vanes are going the opposite way the external slots are. thanks guys.

I always understood it that the vents and slots were supposed to "eat" or "dig" into the pavement. I understand that the internal vanes are what matters but I thought it was pretty standard to correlate the internal vanes with the slots and vents. Could be wrong though. I know for sure that's the way mine are. In accordance with Baer of course and their fine expertise :P