[apez]

I ran a track event a few weeks ago. I keep forgetting to put the brake duct covers back in place. What are the downsides of driving on the street without them? Noise? MPG? Debris? Too cool brakes in cold weather?

[Squidget]

If I had to guess, debris and water. But I am totally guessing.

But I can't imagine it matters very much, really. That's suspension stuff, it's already hardened against all kinds of road hazard crap. I can't imagine something coming through that duct that it couldn't handle.

Also, I snagged this from a similar post on a G80 forum:

Per BMW: "With vehicles with M Compound or M Carbon ceramic brakes, don’t forget to refit the brake cooling duct covers on the front wheel arches. They should always be fitted when driving on public roads, as they protect the brakes against damp and improve the response in the wet. The covers also have an influence on drag and thus also on fuel consumption and emissions."

shruuuuuug.

[apez]

Originally Posted by Squidget

If I had to guess, debris and water. But I am totally guessing.

But I can't imagine it matters very much, really. That's suspension stuff, it's already hardened against all kinds of road hazard crap. I can't imagine something coming through that duct that it couldn't handle.

Also, I snagged this from a similar post on a G80 forum:



shruuuuuug.

Thanks! I will try to remember to refit them more promptly!

[M_Power Rob]

Originally Posted by apez

I ran a track event a few weeks ago. I keep forgetting to put the brake duct covers back in place. What are the downsides of driving on the street without them? Noise? MPG? Debris? Too cool brakes in cold weather?

With it just open, you are losing some of the directional flow of air. You can also put the back side of your radiator at risk by debris kicking off your tire and going through the open vent...

[DutchBoysRacing]

I imagine there is no "real" (significant) downsides/repercussions to the brakes as everything will work still, maybe not "optimally". The only reason to restrict air or cooling to the brakes is...well...to restrict air and cooling to the brakes.

Brake pads have an optimal operating temperature so I they won't be as effective if they don't get enough heat into them, or they'll take longer to get heat into them. I'm thinking this might be an issue in colder climates. Also they might "squeak" more as there isn't enough heat in them or they are very cold.

I run my g87 with the brake covers with stock pads and now EBC RPX pads (track only pads) but I live in Los Angeles (warmer climate). I also track my car multiple times a month so its a PITA to remove them every two weeks and then put them back on. There has no absolutely no issue I've had on a far more aggressive brake compound.