Brake cooling - an idea

CL65 Captain

CL65 Captain

Legendary Member
Joined
30 August 2005
Messages
5,406
Location
STL
I was helping my brother replace the inline blower fan in his boat. This thing put out some air and sits inline with 3" ducting. Hum, I have ducting running to my rotors.... I bet this thing would blow more air than my 2" ducting that snakes its way 4' and makes a tight 90 bend to the front of the NSX. These fans are $20 each and $50 to replace my 2" ducting with 3" and I wouldn't have to run it to the front. So for $100, I might give this a shot and just wire it up to my Accusump switch (only on when at the track). The spec show 135 CFM. All I know is that it felt like it was moving a lot more air than my natural ducting probably does even at track speed. Thoughts????

CWR-31479.jpg
 
I actually have two of those on the nsx.... they are quite nice however, I still wonder what is more efficient... So instead of having to decide I just ran two cooling ducts.

I routed the hose for the blower to the lower area of the rotor hat and had the 2" line running to the rear side of the hat... The only real gripe I have with them is that running the 3" hose in that limited area is quite difficult.

It's worth playing with though... I like having them enough to try putting them in my crx.

just my .02
 
Re: Trade offs, trade offs

Hmmm, I'm sure a mechanical engineer will weigh in soon, but something makes me ask if it wouldn't actually create more drag than just the open duct's friction on track where you need it most. In the pits it would be invaluable, but at 60 mph, there's double the fan capacity (say 290 cfm) available at the duct mouth, (although I'm not sure that's all that relevant:redface:) Assuming the fan delivers 135 cfm in still air (zero static pressure differential), I don't think it will increase flow by that much with a high pressure differential.

I think the trade offs may show the motor is more of a blockage than a help. But I'm just a dumb civil engineer that forgot any fluid mechanics I ever knew, so I'll be interested to hear an M.E. straighten us all out. :biggrin:
 
I honestly don't think that my ducts flow that much air because I have to use 2" and then a sharp 90 turn to go down under the radiator and then another sharp 90, about 3 more feet and then a gently 90 turn to go to the rotor. I have placed a leaf blower in front of the car to see how much air comes through and it does come through, but the only way I have of testing is to compare the new setup to the old via rotor temps.

I wouldn't run this inline, I would probably mount it somewhere close to the wheel well and just run a 3" from the fan to the mount on my brake heat shield. This thing really puts out some air.
 
Last edited:
:biggrin: :biggrin: :biggrin: :biggrin: :biggrin: :biggrin: :biggrin: :biggrin:


<img src="http://www.gtrblog.com/wp-content/uploads/2009/12/gtrblog-nismofesta09-112.jpg" width="800">
 
Last edited:

http://www.stockcarracing.com/techarticles/scrp_0704_brake_temperature_control/index.html

"If that isn't enough, consider using a small electric brake fan to push more air into the rotor. These are inexpensive and becoming increasingly popular on asphalt cars of all types. Spencer cautions, however, that you can harm your overall brake cooling system if you don't install these fans strategically. "Those fans are powered by an electric motor and spin at a constant speed," he explains. "Usually, they move air at about 35 mph. Going down the straights, you can get much more flow than the fans will allow through your ducts, and the fans will actually cause the air to back up and not allow it to get to the rotor. You can keep this from happening by not installing the fans in line with the duct that leads the inlet air to the rotor. Instead, install it in its own path and have the duct from the fan "Y" into the main line. This way you get the best of both worlds."
 
Those fans are commonly used as defogger fans for the front windshield as well as for driver helmet air on many race teams.

I have heard of those being used in the brake ducts but as others have said (and your most recent post), it would be best to have them IN ADDITION to a standard duct and not solely by itself.

Do you have a pic of your current setup?
 
Here are pictures of the setup I did awhile back.. it's still on the car mainly b/c it's such a pain to take off.

I made a home-made diffuser for the front end about 5 years ago and I just added the fans to it... Helped a lot in mounting.

Here is the passenger side from above:
DSC02387.jpg


drivers' side standard air duct:
DSC02388.jpg


and lastly, here is the 3" ducting from the fan... it goes behind the wind deflector then back up and gets as close as possible to the hat... from this picture it looks like it terminates behind the deflector.. :
DSC02391.jpg


Whenever people asked about them I called them my 'low speed' fans... primarily for the reasoning that someone stated above...

seem to work well.. When on, you can feel a breeze blowing thru the rotors at stand still... I figure that has to count for something.. :tongue:

x
 
Last edited:

Similar threads

S
Air con issue???
Replies
5
Views
153
drew
drew
asylum
Tips on suspension settings
Replies
5
Views
1K
Track Addict
Track Addict
Ron1999
Mounting the EPS module due to an aftermarket Sub (or if you just feel like it)
Replies
0
Views
67
Ron1999
Ron1999
Valhalla
Radiator to Vented Hood Duct
Replies
2
Views
488
Valhalla
Valhalla
Chris_Lum
DIY: Coolant Bleed Procedure | 1991-2005
Replies
0
Views
122
Chris_Lum
Chris_Lum
Back
Top