tires and wheels wheels, brake cooling & downforce?

[Guest Anonymous]

Stupid questions may get stupid answers but here it goes:

Is there a type of wheel/rim that will act as a propeller or fan to facilitate brake cooling/moving of air? If a brake duct pumps "cold" air to the rotor wouldn't it be nice if a wheel was designed to suck out the newly heated air? Also If the right type of air dam/splitter was in place and the wheel was designed to really move some volume wouldn't it also help with downforce? Maybe this is taking things a little too far but it's just a thought. Do standard bottlecap/turbine, etc. types of wheels move air at all? I remember reading that newer style steel wheels have larger openings or holes to facilitate better brake cooling.

Thoughts - Suggestions - Ideas?

[MBH297]

You are right in saying that if you have larger gaps in the alloys more air will be able to get to the brake discs, however if you had wheels that had turbine type spokes to facilitate air being forced away from the discs then the wheels in turn would be forced inwards, not very good for wheel bearings, and as you say it would force air from under the car causing a vacum effect thus more downforce, but this would be mainly in a straight line (slowing the car down) as the wheels would slow for the bends thus forcing less air out. You would also need different wheels for the Offside and Nearside.

[Guest Anonymous]

What I meant was the wheel sucking air out from under the car to the outside. If you have brake ducts feeding in air to the caliper, and wheels forcing air IN to the caliper that would be counter productive IMHO. I understand what you mean about downforce on the sprung part of the vehicle but by sucking out air from under the chasis that would decrease the pressure or create more of a vacuum under the car which would pull down the sprung chasis would it not? This would also put inward latteral force on the wheels although probably not that much.

Is this just craziness or do people think of things like this?

[MBH297]

Sorry, see amended post above. Would have helped if i had read the post properly!!

[Mike Self]

as "sucker" fans to generate downforce, and the ducting would be a nightmare. Do a search on the Chaparral 2J race car from the early 70s--it had a flexible lexan skirt around the car's perimeter and a 247cc snowmobile engine driving two large ducted fans to create a vacuum under the car--and thus considerable downforce--enough to hold the car upside down on a ceiling! After four races it was outlawed... neat concept tho, and set lap records everywhere it ran.

cheers

mike

[Guest Anonymous]

Are the holes there so we can see if a guy's running Xdrilled rotors or not or do they serve a purpose? I would assume if you have ducting going to the brakes they would allow air to get out but because it's spinning so fast it would be so turbulant that it would probably do nothing at all right?

[MBH297]

Decreases the unsprung weight, as for the turbulance, not sure.

[Mike Self]

the front brake rotors/calipers, which otherwise would be surrounded on three sides by wheel. Designed correctly, the slots can actually direct cooling air to the brakes.

mike

[BarryA]

Porsche 935's had built in or add-on ducting that acted like a centrifugal fan, drawing air out through the wheel, discharging the heated air at the outer rim.