Question about rotors

[Bojidarcho]

hello, i have a question. i left my car with my mechanic today to change the rotors. the new rotors are drilled but the thing is that from all the cars i have seen the ones on my car seem to be misplaced meaning that the one that should be on the right is on the left and the one that is on the left should be on the right. does it make a difference if they stay like that and should i take them off

[v3bahumut]

I don't think they are directional, it shouldn't make a performance difference but it may look out of place. Wait for another opinion as I'm not 100% sure.

[Bitter]

drilled rotors crack, get slotted or plain.

[Klint]

they dont have a left or right side

[Bojidarcho]

i already installed them and they look good :) i was browsing the pictures of rotors and big brake kits on here and i saw some cars that had them installed as mine so i guess it should be ok. as for the cracking ... ill see what happens and eventually change them again. thx for the heads up

[johnnyGTA]

they dont have a left or right side
.

[TaeMachine]

Make sure there isn't an "R" or "L" stamped somewhere in those rotors. They tell you which rotor goes on which side.

[Bitter]

i already installed them and they look good :) i was browsing the pictures of rotors and big brake kits on here and i saw some cars that had them installed as mine so i guess it should be ok. as for the cracking ... ill see what happens and eventually change them again. thx for the heads up

http://i36.photobucket.com/albums/e3/Pace187/DSCN0156.jpg

[GSBoek]

Vented rotors can in fact be directional (though not always) so it's something to check.

[Bojidarcho]

yea i was looking on the box and the actual rotor but there was no stamp or indication that they are directional but just wanted to check

[CalPencil]

I have those same ones... they don't crack if you take care of them and don't brake so much. If you're the type to slam on the brakes and use them all the time, then... you're asking for them to crack on you.

You shouldn't have to use the brakes at all if you're good enough and fuel efficient enough. Just enough to stop the car in it's final last movements.

If you're going to do some racing where you need to use the brake 80% of the time... then just look into slotted.

Drilled + Slotted is better for a daily driver since it weights less. You'll get better acceleration and fuel economy out of it... not to mention the performance when you come to a stressful situation.

[Bitter]

wrong, they will crack. cast iron drilled rotors crack period. no way around it, even the good cast ones crack and especially the cheap ebay ones.

drilled rotors have less mass to absorb heat, brakes function by turning kinetic energy into heat, the mass of the rotor absorbs the heat and then radiates it to the surrounding air. the more rotor mass the more heat it can hold, the more heat it can hold the better it will resist warping and overheating and stop the car. a rotor with less mass may be able to stop the car but will have a harder time stopping the car repeatedly without suffering problems like warping/cracking. not to mention a large loss in surface area for the pad to make contact with to even stop the car in the first place! and don't get me started on the aerodynamics of the rotor to pad and how slots/drills can cause brake dragging and actually HURT fuel economy.

http://www.stoptech.com/tech_info/tech_white_papers.shtml lots of good info there as a starting point.

if you want to lower unsprung weight get lighter wheels, if you want drilled rotors get a big brake kit with drilled rotors so you'll atleast still have the same or more surface area/mass.