I was thinking of running custom brake ducting to my rotors, cut out a hole in the back of the rotor and run some ducting to that hole from another duct under my cat. Would this be worth it? Or is it a waste?

who cares its cool

All depends how hard you use your brakes and do they get very hot>

What about autox?

run a collector from the front of your car to a tube that directs it the brake rotors

under my car, not cat. lol

go for it, i like to keep everything cool, im doing something of the sort to my car now while i got downtime

I remember a thread about this somewhere and they kept talking about it has to be engineered right so the rotors dont cool unevenly and crack.



They could have been full of it though.

skunks on the other other forum made his own brake ducts from carbon fiber. it has like a 2 inch opening compared to the crooked willow racing ducts and the N-tech ducts which have much larger openings. i am prettty shure skunks is here on this forum also. i think he wanted like less than $200 for his ducts.

Maybe I don't understand what you mean but, if you cut a hole in your rotor you will have to have it rebalanced.



Also if you plumbed your duct work under your cats or anywhere near your exhaust you will be drawing in warm/hot air.



I have thought about making custom duct work for my front brakes but then some things dawned on me...



What if I am sucking up water into the duct work? Maybe not so bad, but oil and petrol would be ingested as well.



Also what if I take in small partiulate matter that is abrasive? Some of it is bound to end up in the wrong place.



Maybe these are valid maybe they are not. What do you all think?

How effective are the stock ducts? I actually removed mine, they only seemed to funnel air to the front of the tire. Plus I don't do track time or auto-x.

Err well not the rotor itself. I was thinking of the metal guard thing that goes behind the rotor. I found a writeup somewhere too once.



http://www.3000gtvr4.com/pages/ramair.html



At least its an idea. I was gonna go looking around and see if i could find some space in my front air dam too.

If you'll notice, the brake rotor dust guard has a bend outward in the front - this is to 'scoop' air into disc vanes that run the circumference of the rotor. brake ducts are designed to aide this action be creating a path for fresh air to travel from. as opposed to a sealed fenderwell, which may have stagnate air at lower speeds.

The stock ducts are not excellent, but don't hurt to have. Personally, I believe that air would be better used directed into a cold air box.



As for making your own, it is not as easy as putting a tube in there. If the car is street driven, then the piping has to be small enough so as to avoid being rubbed when the tire is at full lock (this isn't a problem on race cars since they are almost never at such extreme steering angles). The design of the ducting is crucial also. Air needs to be directed at the center of the rotor since vented rotors are designed to push air outward from their center. This duct should also be virtually sealed to the rotor (not sealed, but very close and has to withstand some vibrations).



The gains you'll see from putting in ducting is questionable. As I've religiously stated before (and will continue to do), the stock TII brakes are pretty outstanding with better pads and lines. Unless it is a track car (read: track, not autocross), it is unlikely you're reaching temps where the ducts would help. Autocross is (relatively) slow and quick, giving the brakes ample time to cool down between runs. Hell, a racing pad doesn't even have time to really heat up during runs so I doubt the rotors are overheating.



As for the cool factor, well, if it's done really well it could be pretty cool. But then you have to think of whether it's worth it, which in my opinion it's not. You'd be better to buy some slotted rotors to look cool (that's a whole nother can of worms there).



I wouldn't, and don't, bother.



Redwood

i had heard that the openings in the lip on the R models was ducted to the front brakes....is this true? i really dont know. just thought it sounded like a good time to find out

In Autox I have difficulty getting my pads up to temp so that they are sticky.



If your doing open track days its worth looking into other wise I think its not worth bothering with. The inportant part is doing it right.



Just make sure you bleed your brakes and have good pads like Hawks in there you'll be fine for Autocross.

for what its worth we run stock brakes (pads too) on the race car (na fc) and its fine. we could perhaps benifit from ducts and slightly more aggressive pads, but thats like 10ths of a second....