Ok, on the new BMW 1 series they have big air intakes on the lower section of the bumper that take cold air and direct it onto the brakes for cooling. I was thinking of maybe incorporating this into our j-bodies. Maybe, take the fog lights out and attach plastic tubing and plumb it to the brakes. And opinions on this idea would be greatly appreciated.
"You can only feed them semen for so long before their legs fall off."
... and you need extra brake cooling because why again?
I had the same idea, but I had the idea of using aftermarket fenders (x1, etc.) and plumbing from there. I personally think it's a good idea, because no matter what car you drive, cooler brakes are better.
Why?!? You do know brakes get extremely hot, right? Just clarifying that for ya. 1) Better breaking. 2) Less rotor warping if brakes are cooler. 3) It's a kick arse idea in my opinion. If you're doing autoX you want cool brakes from all the hard braking. It would be a very unique upgrade! Sure, it probably wont give drastic performance changes, but it will help. I live in Arizona, and brakes get hot without the freaking car running.
"You can only feed them semen for so long before their legs fall off."
make sure u put a grill on it so you dont throw a large stone onto your rotor
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- Sold my beloved J in April 2010 -
I just don't see how your going to get it to function properly. But what ever floats your boat mang.
How are you going to direct it right at the rotor? trying to run a plastic flexible tube in there isn't going to work and get it in there near the strut to point near the brakes. When you go to turn your wheel the clearance between the tire and fender liner its only an inch or two IF that when guys are running 7.5-8" wide 225 series tires. I personally only have millimeters when I am turning. But hey if you can pull something off and make it work, props to you on being one of the few. I'd personally rather just settle for a big brake kit which has cooling veins cast into the rotors and dissipate heat faster.
I was involved in a discussion about this on another board a while back. Someone actually did air velocity testing for autocross speeds. The outcome was that the extra weight (even though its less than 10lbs) would have made it not worth it. A J body doesn't weigh enough to warrant extra cooling, even with stock brakes, on an autocross course. A road race car is a different story. Stock brakes could benefit from the drop in temp, but only on a long course, since the ducts aren't efficient at low speed. Oversize brakes really wouldn't see much, since again, the car isn't heavy enough to overwork them.
Cooler is not always better with brakes. There is a certain temperature the rotor should be at for the best bite by the pads. If its overcooled, the bite is actually less than optimal. So, when you have oversized brakes to begin with, then you add cooling ducts, you may be hurting braking performance. The easiest way to check and see if you actually need extra cooling is to get some brake temp paint (alot of race supply places carry it). Simply brush it on the edge of the rotor and hit the track. Check to see what color it turned, and read the directions to find out the temp. Depending on what pads you're using will determine if its cool enough or not.
Running the actual ducts is the easiest part. There are brackets made specifically for it (check ebay, or any road race supply place), and the NACA ducts are easy to use. I've never seen it done through the fender before, but you would end up needing a ton of hose to route around the unibody rail, since you can't just stick it into the wheelwell through the fender.
Bottom line- its not really a needed upgrade on a J body, since the stock brakes will never see overheating during normal use, and most people who do any type of track work will upgrade to bigger rotors anyways. Also- this isn't a new thing, its been around for quite along time now, sometime around the Can Am era. Mustang Cobras have the entire kit in a bag in the trunk when they come from the dealer, you just install it when you buy it.
X2- Not a new idea, but a good one..... If you're on a track with long straights. These tsraights mean A) tons of air hits the rotors for a few seconds right before B) you get on them hard at the end of the straight and need them at their coolest.
Autocrossing won't see your speeds get high enough to need ducts, nor produce enough speed to do much cooling. Heres a link to exactly what you need if you want to do it anyways.
http://www.ca-automotive.co.uk/single_prod-cHJvZF9pZD0xODQ5.html
Its a uk page, but you can plug some phrases in Google and find a US provider, or just go to a racing shop. As noted above, this is neither new nor uncommon.
I think it is a nice idea IF NEEDED. like james said, get the brake temp paint, and do that....at least take an IR temp of your rotors after racing.
A much easier approach, that lexus uses, is to have an oversized backing plate, that will stick out beyond the offset of the wheel, to grab air in all directions and force it toward the rotor.
much less involved than running pipes.
Isnt there an exotic car that actually has wheels that shoot the air in towards the rotor? The spokes are like fan blades almost
"You can only feed them semen for so long before their legs fall off."
^^^most wheels do the to some extent
you realize other cars used them LONG before bmw did
and cooler brakes are not better , they are next inline to over heated brakes as far a function goes , every set of brakes likes heat to work better
I know it's been around for a long time! I just never thought about it until I went and drove the 135i around. It was just an idea though.
"You can only feed them semen for so long before their legs fall off."
Just to throw this out there. At the last SCCA Evo school I was at, I went 12 runs in a row (never stopped the car, hot lapped) on a 35-40 second course. This happened 54 times that day and never had a brake problem. Brakes were on fire, but there was no noticeable fade. This was stock size brakes with hawk pads and powerslot rotors.
I dont really see a need for vents for street driving. Brakes will never see temps high enough to need it. On top of that, if you get hard on the brakes on the street, it will probably be a while before you need to use the brakes again.
For Autocross, brakes can get quite hot, but but usually speeds are not high enough to make use of ducts. You should be using a pad that operates in a higher temp range anyway.
The only reason it would be wise to use brake ducts is if you road race your car. As a matter of fact, I think it would be foolish of you to not use ducts on a track. It becomes a safety issue there.
And yes, brake ducts have been around a while.
Go Go OG Traction!!
