Brake cooling ducting

[jimnielsen]

from my earlier post...

I did some testing at Phillip Island at the weekend, using brake temperature paint. The outer edge of the rotor is getting up to 600 degree c. This is too hot for these calipers and rotors. The Q4 is a difficult car to add brake cooling ducting to. Especially with the brackets that support the 166 caliper.

The bottom line is that I am going to have to add some brake cooling if I want the system to perform for more than 3 - 4 laps..

has anyone added brake ducting to their Q4 - can you please post some pictures and comments as guidance for others.

Thanks, jim..

[Steve Webb]

Probably not much use to you Jim but the Group A Lancia Deltas used a fan arrangement that bolted onto the front wheels to direct cooling air over the brakes. You can just about make them out in the pic below

[Steve Webb]

Looks like they also used some special wheels as well:

[wrinx]

I've seen the fog lights taken out and the holes used to run ducting to the discs/brakes, no idea if it's effective though.

wrinx

[AlfaJack]

Water sprays?
Don't know if this is the worst idea ever but the racing trucks have it. You could use the IC waterspray supply.

[JBSOUND]

What do you think about "Brake Heat Shields".....

http://hardbrakes.com/index.php?main...products_id=41

[jimnielsen]

The heat shields are not a bad idea. I am going to use ducting though. The problem is..

1. drive shafts are in the way
2. Struts are in the way
3. extra bracket for the 166 calipers is in the way.
4. the oil cooler is in the way
5. the east/west engine mounts are in the way..


best I could do would be 2"....

[1NRO]

Tough to fit it all in the space but the important part is near the rotor, I'd ratch through the link below and see if there's anything that could be adapted to fit. Get them mounted and it should be possible to do a good job off them. There are in-line fans that can be used if drawing air is difficult at the front of the car.

http://motors.shop.ebay.com/i.html?_...g+ducts&_sacat=

[Steve Webb]

Just looking at this from a different point of view, instead of trying to force air in behind the disk, would it be possible to arrange a duct so it draws air away from the brake area (pipework and duct pointing to the rear or the car) thus drawing cooling air in through the wheel?

Not sure how effective this would be, but its something else to think about.

[Steve Webb]

I've been searching out for pic that I saw a while back showing the relative pressures over the body of a car as its moving. Couldn't find the one I wanted, but I did find this one:

From the diagram it shows that there is an area of high pressure at the trailing edge of the bonnet. Would it be possible to run a duct from there?

[hf hpe]

I can't explain in english perfect

but the brake pad must be 1mm with in the diameter of the rotor

[jimnielsen]

hf hpe.. your English is great!! - but Why within 1mm - mine go right to the edge...

[Steve Webb]

I can't explain in english perfect

but the brake pad must be 1mm with in the diameter of the rotor

Is that the inner or outer edge of the pads?

I'm guessing its pretty important to prevent any big thermal gradients. On a vented (or non vented disk) the outer edge of the disk is going to get the most cooling. If you aren't heating that edge of the disk then you are going to get a pretty steep thermal gradient there weakening the circumference of the disk.

Also the other point would be, why bother with large disks if you aren't going to use pads that cover all of the disk.

[Juan AR155Q4]

This image could help, was posted by Nick a couple of years ago:

[hf hpe]

I will ask.
But I've heard that the pad must be with in 1mm inside the outer diameter of the disc, to prevent over heating.
I you see original worn disc there is edge on the outer diameter.

[mpampis_]

Take a look here guys
http://www.scara73.it/carbonio/carb18.html

[Steve Webb]

Thats the sort of thing I was thinking about at the start of the thread. How exactly would fitting them to the front wheels affect the balancing?

[mpampis_]

I guess it is between the wheels and the bolts but you need to balance the wheel with this I guess

[Suzumushi]

has anyone added brake ducting to their Q4 - can you please post some pictures and comments as guidance for others.

Thanks, jim..

Jim
take a look at these

http://betacorse.exblog.jp/i3/17/





found it when looking for TI.Z bodykit cars
as translator says it's from 155D2 car, but it gives an idea how to resolve Your issue with hot brakes.

regards

[Steve Webb]

That looks a useful piece of kit, probably won't help the under bonnet temps overall though, and its gonna be sitting pretty damn close to the ground.

[jimnielsen]

Its an interesting product, and a fine idea.. the real problem that i have though is not on the 'collector' end of the piping, because my car is just a racecar and I can make any holes in the front bumper that I want to allow for air to get into the tubes.. its in the routing of the flexible hose in the area of the drive-shafts and the front struts. There isn't much room..

[Xti]

Probably not much use to you Jim but the Group A Lancia Deltas used a fan arrangement that bolted onto the front wheels to direct cooling air over the brakes. You can just about make them out in the pic below

Besides the fact I always wanted rally type of wheels for my cars, they also have their benefits such as increased shock resistance and brake cooling configuration. As Steve mentioned above...