First Gen Mazda Comp Brake Ducts
 

Hello,
I am an autocrosser just begining to dabble in track days. I am in the process of putting Mazda Comp brake ducts on my car, but I can't see where you get cool air? I thought the ducts would pick up air from below the car, but the ducts point up towards the antisway bar. Do you cut a whole through the frame rail above the swaybar and take the cool air from the raditor area?
Thanks ~ JEB

I wouldn't cut the frame rail.

Typically, you attach silicone hose in either 2.5" or 3" diameter to the brake duct and run it up to the radiator opening or to vents in the valance panel beside the radiator opening. You'll probably need to cut a hole in the plastic fender liners if they are still installed. The 84 and 85 cars have vents already in the valance panel.

You'll have to determine the best routing by making sure the tire clears the hose while the wheels are turned.

My ducting runs just below the sway bar - attached with zip ties.

Brake ducting made a huge improvement on my car - I had big problems with brake fade before the ducting. You'll need good pads too.

Thanks Neil,
I hope it makes a huge difference too, last year I ended up in a field because I just cooked the brakes.

Do they also offer these for the rear?

JEB, I will have to see these when you get them done...well that is if you will ever drive the 7 to a meet :) I think that I have made almost every one for over a year and have only seen your car once...

Well I guess that I am not the one to talk though either.

They are made to mount to an air dam.

Thanks, I am aware that the ones that are being discussed are for the front brakes. But nevermind I don't want to hi-jack JEB's thread.

Sorry JEB

Z

This is what I did, although I can't take credit for it:

"I run a RUBBER flex duct (not dryer vent stuff) forward and behind the bumper into the radiator opening just at the upper corners, and turned into the air flow. You can make a tiny bracket attached to a short (1") piece of 3" exhaust tubing to form the inlet, then slip the flex duct over it and clamp it. You can even flare the inlet, thought I don't.

I have heard of others using the turn signal openings or the GSLSE spoiler with stock low brake inlets with limited or no success. They might be in lower pressure areas, too close to the hot track, or too small in area. Avoid any of these problems."

We run them off the valence on the Spec7's, and it makes a good bit of difference.

I don't use the brakes much, and therefore don't have anything other than the stock setup on my car, but my dad's has the comp ducts and extra large valence openings with some mesh screen over it. No hose to the ducts (yet), but I hear the big Castrol bottles make good adaptors.

When I removed my turn signals and ran *no* ducting to brakes, the brakes had more fade resistance. Just by removing the turn signals.

Thanks guys for your feedback, and thank you for not giving me greif about thinking of cutting through the frame rail. You know how things get when you are tired and trying to soulve problems. Well, I feel like a dolt now that I have looked again and seen the plastic inner fender. I can now see where I sould cut and add hose.

I also got feedback from someone suggesting I sheild the hose from tire wear with a small piece of alumumin. That makes a lot of sense since the hose is VERY expensive.

I will post photos when I am done.
thanks again

yes, please do. :)

Make sure you leave enough slack in the hose to let the wheels turn, but not too much that it flops around and tears stuff up. If you're using the silicone hose, you might also want to put something between the clamps and the hose on the duct because a bare clamp will tear the hose up in the long run (it'll take many, many race seasons to start tearing it up, but I always like to plan on keeping that kind of stuff on forever than replacing it every year!).

for reference:

http://www.mazdatrix.com/faqpics/roadp7/p7011jb.jpg

I got lazy and just zip tied the ducting to the sway bar. The scoops on the backing plates seem to contact the sway, adequatly limiting travel so I couldn't scrape the tubing with the tire anyway.