First Gen MazdaComp Brake Ducts

[Kill No Cone]

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

[CaptainWho]

Connect a 3" duct hose to the duct on one end and a hole in the air dam (no larger than 3" per side) on the other end.

[ddewhurst]

JEB, my first question about your 1st gen RX-7 would be are there loovered openings in your valance below your front bumper ?

If you have a desire to be SCCA legal my second suggestion is that you enter SCCA in a PC search engine then when the SCCA site opens search for the GCR (General Competition Rules) section & read/understand the Improved Touring rules for brake ducts & brake hoses. You will find that ITCS rule 17.1.4.D.6.b. & 17.1.4.D.8.B. spec legal 3" brake buct & 3" brake hose information.

The rules allow 3" brake ducts which have an approx 4" x 7" opening with a 1" mounting flange around the opening at the front side & a 3" round feature at the rear side to attach your 3" duct hose. If your car has a front valance with a loovered opening on each side of the valance you mount the brake duct behind the valance & run a 3" brake hose from the valance to the 3" brake duct at your wheel. If your car dose not have loovered openings you are allowed to cut holes up to a maximum size of 5" x 7" which you mount your bracke ducts behind.

Please note in my post I refer to brake DUCTS & brake HOSES. Both words are important when reading the GCR rules.

After you sort through the GCR rules feel free to ask anything you would like to know more about.

[Kill No Cone]

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.

Thanks for refering me to the SCCA rules, that just makes sense to refer to them. Thanks again and I will post again if I have more questions for you.

I will post photos when I am done.
thanks again

Originally posted by ddewhurst@Jan 9 2006, 02:10 PM
JEB, my first question about your 1st gen RX-7 would be are there loovered openings in your valance below your front bumper ?

If you have a desire to be SCCA legal my second suggestion is that you enter SCCA in a PC search engine then when the SCCA site opens search for the GCR (General Competition Rules) section & read/understand the Improved Touring rules for brake ducts & brake hoses. You will find that ITCS rule 17.1.4.D.6.b. & 17.1.4.D.8.B. spec legal 3" brake buct & 3" brake hose information.

The rules allow 3" brake ducts which have an approx 4" x 7" opening with a 1" mounting flange around the opening at the front side & a 3" round feature at the rear side to attach your 3" duct hose. If your car has a front valance with a loovered opening on each side of the valance you mount the brake duct behind the valance & run a 3" brake hose from the valance to the 3" brake duct at your wheel. If your car dose not have loovered openings you are allowed to cut holes up to a maximum size of 5" x 7" which you mount your bracke ducts behind.

Please note in my post I refer to brake DUCTS & brake HOSES. Both words are important when reading the GCR rules.

After you sort through the GCR rules feel free to ask anything you would like to know more about.

[snapback]70454[/snapback]

[kbailey]

When I ran my ducts I found there is very little clearance between the tire and the engine compartment. I lost some steering travel, and I only used 2.5" duct hose. We bought a used IT7 for my wife and it has a similar issue (that one has 3"). I don't know if you are using the same car for autocrossing, would that be an issue for you?

I don't know your time frame but if you could get to an SCCA event and look at some of the different routings for the hose that might be helpful. Someone more talented than me may have found a way to run the hose and preserve steering travel.

Kevin
ITA/IT7
WDCR

[ddewhurst]

Kevin, I use 3" duct hose from the 3"duct on my 1st gen keeping the duct hose path about as high up as one can using tie-raps in one place. A side comment about not having enough steering. As I have mounted my duct hoses the steering is less, but if I need more steering than I have I am in deep $hit.