Bumper/ splitter clarification round 2

I have a letter in to allow riveting an air dam to the stock front bumper. This is a common install but technically is illegal due to the fact that it is proud of the car outline/shadow. My letter ask for 1/4 in tolerance from shadow.
 
So, I need to start working on a plumb bob with a 1/4" offset? And then you'll need some more because your bumper is not flat and the spoiler sits at 2 degree angle. As a matter of fact, I can't recall seeing a flat fronted bumper. Might as well cover it now. Amend your letter.
 
Mike:

I see an additional issue with dropping an air dam directly down from the bumper, ie:

When bumpers are used or when
they are part of the bodywork, the air dam and bumper/
replica bumper must appear to be two (2) separate components.

I think that your 1/4" may not be an issue, as the part attached to the bumper could be called part of the bumper, or perhaps called the intermediate mounting piece that is referred to (in another section that refers to the max height of the spoiler being 4" above the wheel center, which might be another issue w/ a bumper mounted air dam). But the way I read the quote above is that it is specifically banning an air dam that drops straight down from the bumper or replica bumper. Presumably because this is thought to alter the stock appearance too much..??

Jim:

VW Rabbits (and maybe some Golfs) had a rectangular section aluminum extrusion bumper that's pretty darn flat on the front.

Al Seim
 
Curtis -

I'd say yes, but with the extra 4 inches above tire centerline (ie a height of about 14 inches on a 20 inch tire) I'm sure that would reach the bumper on some cars, maybe not on others. I have not measured mine.

Assuming the bumper is within 14" of the ground (on a 13" wheeled car) then the height rule wouldn't stop simply wrapping a sheet metal or plastic air dam around the bumper and letting it drop down. Which I think is what Mike is alluding to.

But by my reading of the rule section I cited, I think this would fail the "appear to be two separate components" clause. Just my opinion of course.

Al
 
My Chumper Golf had a full airdam with no bumper. I added a bumper, dragged a box knife across the bumper/air dam junction so as to create a visual distinction. You can paint a line etc.
IMHO the rule should be crafted to allow a stock bumper with the dam rivited to the face of the bumper. Simple as that. add 1/2 in tolerance of the shadow and the final tech point is very simple.
 
fwiw, 14" gets onto the flattish part of the front bumper on my Scirocco.

So what about this logic - since the exact makeup of a "bumper" in Prod seems a bit fluid, and if you are defining the air dam part above the "line" as an intermediate attaching piece, why not simply call the part that is wrapped around the front of the bumper "part of the bumper". The part below the line is the air dam, but as long as it sticks straight down it's not outside the plan view of the (now 1/8" thicker) bumper.

Or is that too tortured?

Looking at this another way, no one is going to object, IMO, if I wrap a 1/8" thick piece of plastic around my (already flat fronted) front bumper, correct? It's just part of the bumper. And then I can drop that straight down, draw a line on it and call the part below the line an air dam.

It would save Jim hours of work modifying his plumb bobs....
 
No problem. I'll just return my 1/4" & 1/2" offset plumb bob's and order templates for all Prod bumpers.
 
Letters sent; 18129 air dam , 4in height clarification and allow bolt/rivit to stock bumper .
18130 Driveline/powertrain clarification; Flywheel to drivenwheel ( not tire)

18131 Intake coatings/heat shields. Clarify that paint/thermal barrier is modification. bolted on heat shield is not as long as it covers 50% plus 2 in. .
Add that one air box per car so that we dont have separate air boxes to cool intakes and another to feed the engine.
 
Protech Racing":3dpe5y10 said:
Letters sent;

18131 Intake coatings/heat shields.

Clarify that paint/thermal barrier is modification.
Click to expand...

When PCS's are compared you'll find through the 2007 PCS on the 1990/1993 Miata spec line, "Stock intake manifold only-may be port matched on port mating surface to a depth of no more than 1". Balance tube may be partially or fully blocked. Manifold may not be otherwise altered."

When 2008 PCS re-write is compared to 2007, you'll find, Drive Train Level 1, "Stock and permitted alternate components of the drive train can have thermal barrier and friction altering coatings applied." This same Drive Train Level 1 allowed modification rule was carried forward, unintentional or intentional to the Drive Train Level 2 rule set of the PCS.

When we look at the Level 2 philosophy from it's inception during the mid 1990's one of the purposes of Level 2 car building was and should continue to be so is to not allow the build cost to go astray. From this perspective this thermal barrier and friction coating should be allowed only in prep Level 1. Yep, I read the comment about the manifold coating only costing $300.00, along with 9 other $300.00 items with thermal barrier and friction altering coatings and we have $3,000.00 spent. That folks is not keeping cost from going astray.
 
BLinn":3b3bdemz said:
Protech Racing":3b3bdemz said:
Did the undertray description get moved or deleted?
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I don't think the Prod rule ever had an "undertray" description. IMO, there is an area described for the air dam (can't see if from above beyond the profile of the bodywork, can't be higher than 4" above CL of wheels, and no further back than the forward-most part of the wheel opening). You can build whatever you want in the area as long as your not cutting/moving up existing structure/bodywork. So if you wanted an undertray, I believe you can have one going back to the front edge of the wheel opening. Mounting brackets are not allowed to go beyond the wheel opening either. My 2¢ but I didn't go back and re-read the rule.
Click to expand...

Curious to know more on this clarification? I didn't see anything in the book either about undertrays. And is it to the front axle or leading wheel well edge?
 
Funny that with all of that in the front you can barely even see that there is a rear wing on the car. I would think that to achieve balance you would need three McLaren Mk8 wings.
 
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