Came up in conversation yesterday with a friend and I have no clue execpt to say damn hot, real damn hot...

 

500+

 

That's why powdercoating those puppies is critical when tracking the car.

We extracted some data from Mercedes a few years ago when we were doing some caliper work, and our target temp was 800 based on the feedback.

 

How much do you think GT3 brake ducts do in cooling down the brakes then? And are they a good investment if I track the car?

 

Thread revival. No one answered this question and this is a cheap mod. Maybe worth it for a track car, but is it a good upgrade for a hard driven street car?

 

Yes, the larger sized brake ducts does wonders! I run the largest gt3cup sized ones on the street and track!

 

They are better than stock. But probably won't make a difference for street. For serious track use with aggressive pads, they may not be enough. You need GT3 internal scoops. See here:
http://forums.rennlist.com/rennforum...-mod-pics.html

 

You'd be hard pressed to overheat stock brakes on the street. Or even keep them at their best operating temp. I mean that seriously. In fact you probably want LESS air cooling on the street.

Brakes, like the engine have an optimal operating temperature as you drive fast and straight for a long period of time (and by long I mean 15-20-40 seconds like you would on the straight of a track) the brakes cool way down and it takes stop after stop after stop in succession without much time to cool in between to get them really hot.

Your brakes will stop better when they are warmer that cold (to a certain extent) and it takes a track or full bore on a mountain road with lots of hard braking (I mean 70-90% pedal pressure).

I would not advise brake cooling ducts for street driving. Even on twisty roads you aren't on the brakes enough.