Redid my front brake cooling ducting

Joined
30 August 2005
Messages
5,406
Location
STL
I had 2" air ducting to the front brakes and made a bracket that attached to the front near the caliper. However, I think the caliper was blocking most of the airflow so it wasn't getting exactly where it need to be - inside the center of the rotor hat.

So, I bought some splash shields (threw my old ones away) from a PRIME member and rerouted the air duct hose to the rear of the rotor and have it ducting so it goes right into the center of the rotor hat.

Hope it works better! Will know on my next track weekend - 9/13.
 

Attachments

  • FILE0006.jpg
    FILE0006.jpg
    86 KB · Views: 2,199
  • FILE0007.jpg
    FILE0007.jpg
    69.2 KB · Views: 1,379
  • FILE0008.jpg
    FILE0008.jpg
    60 KB · Views: 1,378
Last edited:
I have 3" duct's.

I pulled the ac condenser and added a inlet duct.

http://www.pegasusautoracing.com/productselection.asp?Product=3624

I mounted the inlet duct inside the plastic housing for the condenser.

There is a about 3 feet of hose that snakes around the suspension and to the breaks. I have it directed at the hub between the caliper and hub.

I have after market breaks there is a bracket to offset the calipers.

My front breaks stay pretty cool. I haven't figured out how to do something similar for the rear breaks yet
 
Have you added the brake scoop from a 993 to the front A arm? I cut a hole similar to yours in the front of that splash guard to direct air from the scoop right into the rotor. Credit goes to the SE NSXers at Road Atlanta who showed me this one after my brakes overheated at the end of the front straight and I found myselft getting an up-close look at a 911's engine cover at 100 mph. I can say that with Motul, Porterfield pads, and this mod I've never had anymore trouble with the stock brakes.

Cheers.
 
Have you added the brake scoop from a 993 to the front A arm? I cut a hole similar to yours in the front of that splash guard to direct air from the scoop right into the rotor. Credit goes to the SE NSXers at Road Atlanta who showed me this one after my brakes overheated at the end of the front straight and I found myselft getting an up-close look at a 911's engine cover at 100 mph. I can say that with Motul, Porterfield pads, and this mod I've never had anymore trouble with the stock brakes.

Cheers.


Do you have any pictures showing the 993 set up? TIA.

As an FYI, there are much better street/track or track/street pads than Porterfield .......
 
FYI: I am now running Dali Air Deflectors to the front of the rotor area, 2" air ducting to the rear center of the rotor hat, Motol 600, and Hawk DTC60s.

Rear has 2" ducting running from under the car to the rear of the rotor and Hawk HP+.

My problem was never fade, but excess heat spider cracking the front rotors. I am just trying to keep the temps down to make the front rotors last a little longer.
 
Do you have any pictures showing the 993 set up? TIA.

As an FYI, there are much better street/track or track/street pads than Porterfield .......

And I'd be willing to argue that the Porterfield's will give you all the stopping power of any of your pads at half the cost. I've tried the others, and stuck with Porterfield, R4s on track, R4S for the street. Would love to try the R-111s next time on the track.

Here's the description of how to fit the 993 air deflectors:

The parts in question are Porsche #993-341-083-00 (left) and 993-341-084-00 (right). Hoehn Acura/Porsche charged me $11.56 each.

After looking at a 993 on a rack to see how Porsche used this deflector, I noted that its upper edge corresponded roughly to the center line of the brake rotor, and that it's outer edge terminated about 1-1/2 inches from the rotor backing plate. The deflector is mounted with the part number molded into it's back reading upright.

The NSX already has a small air deflector mounted to the front of each front lower A-arm (although interestingly the shop manual refers to these as "shields" which they undoubtedly are as well). The NSX deflector is mounted by two horizontal 6 mm bolts into the front of the lower A-arm, and one vertical 6 mm bolt through a lug at the rear of the deflector and into a threaded hole in the top of the lower A-arm.

The Porsche part is held onto a 993 by two vertical bolts through lugs at its rear. It turns out however that one of those lugs is close to where it needs to be to use the NSX's vertical mounting point. All that's required is a metal bar with two 1/4" holes, centers 7/8" apart, to extend the Porsche mounting lug to the threaded hole on the NSX A-arm. I used a piece of 1/8"x1/2" aluminum (about 1-1/2" long), and countersunk one of the holes so I could use a 1/4" flat-head screw to hold that end of the bar to the underside of the Porsche deflector lug because I wanted to keep the deflector mounted as low as possible. The other end of the bar attaches with the original 6 mm NSX bolt in its original location on the upper surface of the lower A-arm.

With that done I used a scratch awl to punch through the deflector at the two threaded holes in the front of the lower A-arm, drilled out the two punched holes to 1/4", and fastened the deflector to the A-arm with the original 6 mm NSX bolts. This of course isn't a particularly well-engineered attachment, since, unlike the original NSX deflector and the lugs on the Porsche piece, there are no pressed-in metal bushings, so you have a threaded fastener bearing against a piece of plastic. A lot of heat, a little vibration and maybe some aging and that fastener will probably come out. For now I just Loctite'd the threads and hoped for the best, but will eventually sink a couple heated bushings into the plastic to make the anchoring more secure. Alternatively you could use 6 mm shoulder bolts like those that hold the NSX spoiler lip and license-plate bracket on. I note though that the original deflector mounting bolts have the green "anti-corrosion" coating, and thread into aluminum, which these shoulder bolts do not in their original application.

In any event, the new Porsche deflector hangs down a couple more inches into the under-body airstream than the original NSX one, and, like the NSX one points pretty directly at a couple holes in the brake backing plate that lead to the inside of the center of the brake rotor, as well as at the general vicinity of the caliper: exactly where you want LOTS of cool air flowing.
 
I'm with hrant the porterfields are made of balsa and pumice ie they last 1 track wkend so half the cost for something that wears out 3x faster.:wink:
 
can you take photos of this 993 setup?

I need to get something sorted out within the next couple weeks.

Thanks,
Mark
 
http://www.pelicanparts.com/catalog/shopcart/911L/POR_911L_SUSshk_pg2.htm

$12.50 each :biggrin::biggrin::biggrin:

imgdsply.cgi
 
OK. Ordered them.

I suppose I will figure out how to get them installed when they get here.
 
What mounting hardware did you order?

I appreciate the above post on how to mount them, but will confess I am having trouble visualizing it.
 
Got the ducts. Looks like you could just grind off the ridge that porsche uses to to mount them, drill a couple holes and tighten them down with the factory deflector bolts.

I have to leave in the morning for work, so I won't get a chance to try this for a while. Has anyone else already done this? If so, please document it with some photos.
 
Did you finish this mod? Looks like it would work well. Really interested in how it turned out.

Got the ducts. Looks like you could just grind off the ridge that porsche uses to to mount them, drill a couple holes and tighten them down with the factory deflector bolts.

I have to leave in the morning for work, so I won't get a chance to try this for a while. Has anyone else already done this? If so, please document it with some photos.
 
Has anyone finished this modification with ducting for the front brakes? Sounds like it helps alot and not that hard just want to know about some parts. It will be a perfect DIY winter project.
 
Get 12' of 2" ducting from pegasusautoracing.com

Then take the plastic piece that covers the a/c condenser hose off. Cut a 2" hole in it (I checked - this part is $25 ea if you want to go back to stock).

I then took some of the putty epoxy (easier to work with) and attached the hose to the back of the pastic piece.

AirDuct.jpg


On the other end (rotor) I cut a hole in the brake shield and trimmed off all the extra area.

Then found a flexible exhaust piping at Autozone, just so I would have a little bit of adjustability, and epoxy puttied that to the brake shield. I then slid the air ducting over this piping and O clamped it and added some friction tape over it just in case to prevent any rubbing/tearing of the air ducting.

attachment.php

attachment.php


This is before I trimmed off all the extra off the shield. You can't really tell from this photo, but I used the left over epoxy putty to build a little ramp to angle the air towards the center of the rotor.

attachment.php


Ok, since the wheel and rotor was already off I went out and took some cell phone pics of the shield below.


Jim
 

Attachments

  • Photo_121308_004.jpg
    Photo_121308_004.jpg
    79.8 KB · Views: 159
  • Photo_121308_003.jpg
    Photo_121308_003.jpg
    80.1 KB · Views: 162
  • Photo_121308_001.jpg
    Photo_121308_001.jpg
    74.9 KB · Views: 157
Last edited:
I have been running on this setup all year. Depending on what pads I am running and ambient temps the avg drop is around 150F on the fronts and abpout 80F drop on the rears. This is the rotor temps after pitting in (no cool down laps) using one of those laser gauges. Next year I will buy some rotor paint to see what the on track temps are getting to.

I have had no fade issue with my brakes as long as I am running a decent pad and the rotors managed to last the entire season 14 events before one finally had a crack long enough that it's replacement time.
 
Last edited:
Back
Top