So I'm about to change the brakes in the rear to HPS pads and new rotors as the stock mazda pads were starting to warp last summer on track.

My question is do you guys keep the dust shields on the car or rip them off to try and get better air flow to the rotors? From what i've read rotors will tend to warp when they are hotter on one side than the other. I'm thinking these shields are doing more harm than good.

My car only see's about 3-5000km and 3 track days per summer and only in nice weather so I'm not to worried about crap going into the brakes.

I did some searching and didn't find anything so let me know what you guys think.

 

you probably want to keep them since you would have to press out the hub from the spindle to remove the dust sheild. once you press out the hub, the race seperates from the bearing and you have to replace the bearing.

front dust sheild can be easly cut off without the headache of pressing in new bearings.

 

Keep them. You gain nothing by removing them.

 

It would be pretty easy to cut them and rip them off without having to take anything else apart.

 

I think that's a hard decision that you are going to have to make with no real data behind it. Someone would need to collect airflow or fine resolution temperature data with and without and that isn't going to happen any time soon anywhere but at the Mazda development lab. The heat sensitive paints that are available to paint the rotors aren't fine enough resolution to show this difference (I don't think).

You would remove the shield if it was primarily a shield, keeping rocks out of the rotor. You would not want to remove it if it was primarily there to route air to the eye of the rotor. It is probably there for both reasons and without it the straight-vaned rotors are going to have to pull air from what will be a lower pressure zone at the center of the rim. I think the key to getting good cooling is to get as much air through the vanes as possible.

I did cut these away because a forum elder here recommended it, but then got to wondering if that was actually the right thing to do. I never had any problem with the rotors before or after, so that information really doesn't tell you which is better, just that they can be made to work without.

I suspect your "warped" rotor is actually your pads overheating and clumping material on the rotor, not the rotor overheating. Get race pads for the track, with new unbedded rotors (I use the cheapest Centric rotors) and don't try to use the same rotor with different chemistry pads. That I know doesn't work.

 

Great thanks for the info. I think I will leave them on for now and see how it goes.

 

The dust shield is also a heat shield. If you take it off and there are any rubber pieces or wires close to that brake rotor you want to wrap them with something to reflect the heat. The danger is getting cracked ball joint boots and tie rod end boots, well at least on the front end. The rear end might be ok.

The brake rotor is also vented (center breather) so removing this shield won't have as big of an effect as it would if they were solid rotors.