minitech

Brake cooling is a major issue with HPDE. Has anyone thought of putting inline fans in the 4 inch brake ducts in front? So while in HPDE turn on the high output fans to blow air across the brakes at a constant air pressure whether going fast or slow; while stopped and cooling off?

I've been looking around at the fans some and some claim good pass through flow when they are off so wouldn't effect stock driving. There are fans that would drop inside the tube easily.

Just wondering because the ducts are there already.

sperkins

davidfarmer

they are relatively common in racing, although I've never done it.

So a 4" round duct gives nearly 800cfm at 100mph, so I think you'd need at least that much flow as a baseline. I don't know how much cost/amperage you'd need to get 800cfm per duct, but I'd be interested to see what you come up with.

vms4evr

I thought of that before. Only for helping pull air out of the engine bay. Then thought about inline in the brake ducts. 3" or 4" bilge blower from an inboard/outboard boat would be cheap. About $30. Something like this.

http://www.overtons.com/modperl/prod...ID=1008&r=view

cgh1

I never have done the fan thing on a non race car but then I don't really care for the way the brake ducts are plumbed on the C5/C6 (esp. C5).

As an alternative, on my C5s, I got a couple of NACA ducts, trimmed down the bezel to fit in the stock nostril openings of OEM brake ducts and then put swimming pool vacuum cleaner hose on each port of the NACAs (the dual ported ducts). From there, I routed one hose to the center of the rotor about 1/8th of an inch away; and the other I pointed at the caliper, again within an inch of contact. Using hi-temp zip ties I secured the hoses where they'd move with the wheel/brake system up front.

I got all but the NACA ducts from Home Depot for less than $30 (50 feet of vacuum hose - lots left over) and I never had another issue with my brakes.

When I got rid of each car, I'd kept the OEM system and simply reinstalled it in about 30 mins per car.

I posted a how-to out here some time ago with lots of photos, etc. but that was several years & server migrations ago... don't know if it's still hanging around or not.

The thing with fans is you have to get one that not only moves enough air but also rotates at a speed high enough that it doesn't get in the way and negatively impact (restrict) airflow at high speed. David (Farmer) is very knowledgeable in those kinds of things (as displayed in his post here) and he could probably make some recco's on how to accomplish your mission with fans.

minitech

Anyone know what they are called in racing, just to be able to search for it?

Maybe connect up so when switched to the OFF position they generate power to charge the battery with the 400cfm at 50mph avg (is the cfm a linear number for flow on that?)

0Randy@DRM

Well a long time ago we had a tube and a tube with a fan on our flow bench. The fan actually restricts airflow and causes less air to go into the brake system. With the fan on it reduces flow even more.

Randy

aggie_corvette

you could always try one of these, i have no idea what the CFM is though.

Ebay
electric supercharger

http://cgi.ebay.com/ebaymotors/Turbo...%3A1|72%3A1171

or try a ducted fan from an RC airplane

http://cgi.ebay.com/60mm-6-Blades-Du...%3A1|294%3A200

kmagvette

OK, that "Electric turbocharger" is just plain funny. I have many year of working on boats and that sure looks like a bilge blower to me.

I had a slightly different take on the use of blowers. I pondered leaving my DRM Ducts/Hose alone, but using the blowers to get air on the calipers. Sounds like a decent idea when car guys and alcohol are mixed.

AU N EGL

brake cooling fans on ebay
http://motors.shop.ebay.com/__?_from...g+fans&_sacat=





$22 each

kmagvette

More NMEA certified bilge blowers...but at a good price

yakisoba

Of course, you already have a fan in your car that hardly ever does anything... The AIR system fan. Normally, it blows fresh air into the exhaust manifold just post startup, to make sure the can can pass a cold emission test. However, it shuts down and doesn't work thereafter.

I didn't come up with this but thought it was pretty trick: A friend with a tracked C4 put his AIR fan on a switch, and ducted it over to his rotors. He's actually got two hoses pointed at them: One from a nice high pressure spot on the front of the car and one from the old AIR system.

Often, your session will get flagged in, and you have to come into the pits from a hot lap, or you will get flagged to a halt on the course. In those cases, the brakes have no time to cool and could very well crack a rotor. The fan in the AIR system helps with that.

Nice use of a system that I would have just pulled for weight from most racecars.

flink

Yes, I had a couple of those on the GTO for a while:



powered off the foglights and positioned so they wouldn't get rusted up if it rained.

They were too much fuss to use and I felt that they weren't necessarily any better than using natural flow, especially on fast tracks. So I dumped them and installed dual ducts instead.

I still go through brake components at supernatural speeds though

AU N EGL

Did not LG say he only used brake fans on Yellow flag laps too cool the brakes when there is not enough air flowing ?

Bill Dearborn

Even if they improved air flow would they really fit in a street driven C5? The description says they are 4 inches in diameter and 8 inches long. Not sure where I would mount them.

Bill

0Anthony @ LGMotorsports

Exactly....once the car is moving at 100-150 + mph down the road the fan is more of a restriction than it is a benefit.

If you were doing endurance events and might see a caution period of 5-8 laps then yes you may see a use for them, but even at that it would be track dependent.

Our cooling ducts work very well and would not need a cooling fan for HPDE guys, or those even running 1 hr sessions on track.

sperkins

Huh? You talking about aluminum?
Link?

0Louis @ LG Motorsports

Yes, they impede flow at high speeds. You need a true brake duct, it will be much much more effective than the fans.

Fans= 12ga shotgun aiming at a deer....

Good brake ducts= 7mm magnum aiming at a deer

John Shiels

buy a fan and run it into a hose at 100 mph then do the same thing with just a hose and the testing will be over.

cgh1

Nope, NACA ducts are brand of ducts that are used in focusing air direction. Here's a link to the model I used and removed the bezel.

The vacuum cleaner hose was not aluminum, it was industrial grade vinyl hose, that serendipitously has a high melting temp.

Hope this helps.