Sorry for the n00b-esque question... the reason I'm asking this here is that I trust the opinions of those who frequent this forum.

I'm about to upgrade my cracked and spongy stock brake pads. However, my rotors are visibly grooved. For whatever reason, all WRXs seem to do this. My question is, should I get my rotors turned before installing the new street pads? I've read that turning the rotors removes heat-dissipating rotor material, and makes them more likely to warp. I've also read that rotors don't so much warp as pad material gets deposited unevenly on the rotor surface, which is what causes the pedal pulsing etc. one might attribute to a warped rotor. By that theory, wouldn't that make rotor turning a viable option? Should I just install the new pads on the grooved rotors, or get them turned so they'll bed against a relatively flat surface? Yes these rotors will see track time with a dedicated set of track pads which is why I'm concerned with the warping issue. The rotors are also not so heavily grooved as to warrant replacement at this point.

Thanks in advance,
Chris P.

 

depends on how bady grooved they are. when you turn them, youre removing all the material up to the thinnest grooved portion to make the whole rotor flat. i think the problem with grooves is that they wear the pad out more, since the pad will shift and always wear out faster at the highest point of the groove and make the pad wear uneven eventually, but not necessarily to the exact pattern of the grooves on the rotor. the pads will never smooth out the rotor.

about making them warp easier, well, mass determines how much heat or energy the rotor can contain. when you remove the mass, you remove the heat capacity, also just making rotors generally thinner which makes rotors warp easier.

so depending on how badly grooved your rotors are, depends on if turning your rotors are worth the money and there will still be enough meat left on the rotor after you turn it, as opposed to just getting new rotors.

there are ppl who will say replace rotors and pads together, ppl who say otherwise. i dont think its necessary to do so. replace each as necessary.

 

My personal preference is to shave street rotors (including cars that are put on track occasionally) and replace race rotors (on a car that is only raced, by the time it's that grooved, it ususally has heat fractures as well).

 

I would turn the rotors if they are going to be used mostly on the street with street pads. If you decide to track your car more often, switch to a dedicated set of pads and rotors. While your there changing the pads, its not much else to swap out the rotors....at least on Hondas. Dont know about them damn Subies.

 

Just like the previous posts, one factor to help you decide is your intended use. Are your rotors subjected to high temps like road racing and open track? Or are your rotors used for autocross and daily driving. In my case, road racing, I just replace my rotors. Also what are the cost off sets? Some find that for a few $$ more, you can just get new rototrs. Finally factor in the costs if you are doing the brake work or paying someone to do it.


[Modified by ITACivic, 5:03 PM 7/31/2002]

 

My .02, take it for what it's worth:
I bought a second set of rotors for track use only. When I change to the track pads, I take the extra 10 minutes per wheel and swap out street rotors for track rotors. The track rotors only see the track compound pads, the street rotors only see my stock pads. No problems with different compounds wearing onto the same rotor, plus, if I happen to warp one of the track rotors, I don't have brake shimmy when I'm back on the street...
Not too terribly expensive for an extra set of stock rotors...

 

Good point NC. Switching pads on 1 set of rotors will work, but will have to re transfer pad material over. Having a dedicated rotor for a dedicated pad will work best.

 

Chris my rotors were also grooved with the factory pads.
Grooved enough for a master tech to take notice

After replacing the pads with aftermarket (ultimates) the grooves went away.

I would say just leave them as is.

Evan