Improved Touring: Air Dam ?

[zracre]

exactly...It even says if no air dam is used you may cut bigger holes...the custom air dam is permitted as long as it follows the rest of the size and fitting rules.

[jmark]

Originally posted by darrinV@Nov 20 2005, 08:11 PM
Great info guys. It's actually not on my car. That's a stock photo from MSA. The urethane air dams definitely sound more survivable. I'm looking at ways to make it more aerodynamicaly efficient.

I made the decision this week and bought a 240Z set up for ITS. (photo attached) Can't wait to get it on the track!

Darrin

[snapback]66090[/snapback]

Darrin,
You bought a great looking Z car. Where will you be running it? Regards, Mark

[lateapex911]

Greg, not to be argumentative, but I am losing you somewhere.

I think you're saying that I can cut away at my valence, and am not limited as I am using an air dam.

But the rule reads"

Where an air dam/spoiler is used, two total openings may
be cut in the front valance to allow the passage of up to a
three (3) inch diameter duct leading to each front brake/rotor
assembly.

Now I read it to say that "Where an air dam is used..." (thats what I'm doing), "two total openings may be cut in the front valence....."

Thats where I lose you. Where does it say I can cut, say four openings for TWO 3" ducts?

I hope this is me being stupid and not reading the rules at face value!

Here's a pic of my car. Under the air dam is the stock bumper cover which curves downward, and indeed has two opeings (louvered) in it from the factory. If I duct under it, I am breaking the ride height rule ..(and being dumb).

[Greg Amy]

Originally posted by lateapex911@Jan 25 2006, 08:18 PM
...I am losing you somewhere.

There are two cases when/where you can cut holes and use brake ducts: with and without an air dam.

First, the rule in the brake section - 17.1.4.D.6.b - says you're allowed to use air ducts as long as there are no other changes to the body/structure. Thus, barring any further restrictions, there are no limitations in terms of number and/or size.

Second, the air dam rule - 17.1.4.D.8.b - specs out how you can make the air dam, and allows openings in that air dam for ducting air to the brakes. There are no listed limitations as far as number and/or size of these ducts.

Third, however, further down that same section specifies that IF you DO use an airdam, you may cut holes in the valence of the car, and if you do cut holes in the valence, you are limited to two holes which route air via 3 inch ducts. Note that this does NOT further limit what you can do if you cut holes in the air dam, only the valence.

Side note: the "valence" of the car is the downward/rearward sloping original body part, typical what you would mount the spoiler to on the front and below the radiator support. "Valence" does NOT incorporate any add-on air dam.

The last paragraph of that same section specifies how you may cut holes in the valence of the car, and IF you DO NOT use an airdam yet DO want to cut these holes in the valence, you are limited to two holes of 5x7 inches which route air via 3 inch ducts.

So, again, 17.1.4.D.6.b allows brake ducts but does not restrict them further, 17.1.4.D.8.b allows holes in the factory valence of the car and restricts those modifications to the OEM part. There are NO RESTRICTIONS to what you can do vis-a-vis holes and ducting if you do it entirely in the air dam and leave the factory parts alone.

Using your photo as an example, you added ducts to the air dam, which is the part mounted (screwed?) below the center of the OEM bumper cover (I'm guessing that's the factory dealer-optional air dam?) In your case, AS LONG AS YOU DO NOT MODIFY THE ORIGINAL PARTS OF THE CAR, you can make those ducts and hoses as large as you like. HOWEVER, if you choose to modify the original valence to route the hoses, you are limited to a 3" duct.

Capiche? - GA

[lateapex911]

caprice! or something like that. So in my case I MUST go thru the valence (noo other way) so I am limited. thats what I thought, LOL.
thanks!

[ddewhurst]

Greg, did you get my number ?

***Capiche?***

No-capiche, I'll get back to it later when I have more time.

[kthomas]

Don't forget on a Z most aftermarket air dams replace the valence, which is not legal to remove, so you usually have to engineer something to mount the air dam. The Wittel car mentioned on the first page of this thread was built before ANT cutouts were allowed in the valence, and yet it still had THREE 3" ducts going to each brake. Four from the cutouts located in the air dam (and snaked arouond the intact stock valence) and two mounted behind the grill. Like Mr. Donnelly says, if you come to Road America or Road Atlanta you need all the ducts you can get on a Z. Eventually.

[tom91ita]

For what it's worth...I got a roll of sheet plastic from Performance Bodies. Built a front brace with two NACA air ducts for the brake hoses and covered the brace with the sheet. What I looked for the most was that it was no lower than the bottom of the front wheel and no higher than four inches above the center of the front hub.
GnC
[/b]

did you use the plastic similar to this?

http://www.performancebodies.com/store/pro...%5Fid=2202%2D10

how did it work for you?

tia, tom