Understanding the new splitter rule(s)

blamkin86

Well-known member
Just looking to get people's thoughts on the new rule(s). What was the point of all the changes?

A. The spoiler/air-dam shall not protrude beyond the overall outline of the body when viewed
from above, perpendicular to the ground, or aft of the forward most part of the front fender
wheel opening.
B. The spoiler/air-dam can be mounted to the body, chassis and/or frame and may extend no
higher than four (4) inches above the horizontal centerline of the front wheel hubs. An
intermediate mounting device may be used in locations where the front body-work is above the
four inch maximum.
C. The spoiler/air-dam shall have no support or reinforcement extending aft of the forward most
part of the front fender wheel opening.
D. If the spoiler/air-dam covers any portion of the stock grille, an opening must be created in the
spoiler/air-dam. The width of the opening must be equal to or greater than the widest
horizontal measurement of the portion of the grille that would otherwise be covered. The
height of the opening must be equal to or greater than the distance measured perpendicularly
to the ground between the lowest and highest point of the portion of the grille that would
otherwise be covered. The opening in the spoiler/air-dam must be symmetrically aligned in both
planes of the grille.
E. Openings in the spoiler/air-dam are permitted for the purpose of ducting air to the brakes,
radiator and/or oil coolers. Openings can be cut in the front valance to allow the passage of up
to a three (3) inch diameter round duct hose leading to each front brake. These openings can
serve no other purpose.”
 
By breaking apart the old single, really long rule, the specific allowances are easier to identify, follow, and reference. Clarifications were also made to the overall height of the air-dam and the use of an intermediate mounting panel where necessary, and a clearer allowance for an undertray was added.
 
C. The spoiler/air-dam shall have no support or reinforcement extending aft of the forward most
part of the front fender wheel opening.

I am confused by this part. Is support or reinforcement supposed to mean that it cannot attach to the chassis/anywhere else after the front fender wheel opening? Or, is a rib in a piece of material considered "reinforcment" and that cannot be aft of the front fender wheel opening?
 
I would understand the rule to mean no part of the spoiler/air damn shall be behind the forward most part of the front fender
wheel opening.

I have viewed air spoiler/air damn support or reinforcement behind the forward most part of the front fender wheel opening and had this been checked from my rule understanding it would be found to be illegal.

Different strokes for different folks. :mrgreen:
 
kruck":14a8muyc said:
Clarifications were also made to .... the use of an intermediate mounting panel where necessary...
I don't understand what an intermediate mounting panel is. Can you explain? Is this related to the problem that you had in at the Runoffs after qualifying?

blamkin86":14a8muyc said:
D. If the spoiler/air-dam covers any portion of the stock grille, an opening must be created in the spoiler/air-dam...
I've never understood the use of "IF" that starts this rule. To me it says, IF it does, then make changes so it doesn't. So IMO the rules should say, "the spoiler/air dam can not cover any portion of the stock grille/opening as viewed from the front, level to the ground plane".
 
Protech Racing":24x5idm6 said:
Yet, we still cant rivit it to the front of the bumper. Fail.

So this isn't legal?


So I have to figure out a way to attach brackets to the underside of the same bumper cover and then attach to that bracket such that there is a gap? What is wrong with the way I built it to start with?
 
That looks legal. I am talking about attachment at the front edge of the bumper. Yours is fixed below the bumper and behind the shadow line dropped from the bumper face.
 
So can you put a splitter on the bottom of that air dam in the picture as long as you don't go past the edge of the bumper? I could mount front lip braces to the air dam or the area below the bumper and under the bumper but not on the front edge of the bumper.
is that correct?
 
Yet, we still cant rivit it to the front of the bumper. Fail.

Some people don't want prod cars to look like Lemons cars. The CRX pic looks fine because it appears to be inside the vertical plane of the car (behind the bumper).

So can you put a splitter on the bottom of that air dam in the picture as long as you don't go past the edge of the bumper? I could mount front lip braces to the air dam or the area below the bumper and under the bumper but not on the front edge of the bumper.
is that correct?

Yep
 
From the glossary:

Air Dam – An air control device at the lower front of a car, intended to
divert some of the air which would normally pass under the car when the
car is in motion.

I don't see any wording in the new rule that allows a splitter. I do see splitter-specific rules in the Touring category.

I think you could argue that a splitter's purpose is greater than diverting some of the air under the car - that is, a splitter is intended to add downforce that would not be there were it not present, and there were only an air dam.

Not trying to be difficult here- but this rule (now rules) really need some more thought; especially is splitters are supposed to be legal.
 
Simple. The shape of the spoiler is not defined, just it limits, therefore a "splitter" which is part of (integral with) the "spoiler" is part of the spoiler and therefore can extend back to the front of the wheel opening.
 
blamkin86":19y823m7 said:
I think you could argue that a splitter's purpose is greater than diverting some of the air under the car - that is, a splitter is intended to add downforce that would not be there were it not present, and there were only an air dam.

Not trying to be difficult here- but this rule (now rules) really need some more thought; especially is splitters are supposed to be legal.

That is the same purpose as an air dam then. Diverting air from going under the car reduces the pressure under the car and creates downforce. It's pretty simple IMO. The device is allowed within a specified envelope, which provides freedom to increase the amount of air diverted from going under the car with a profile that extends forward underneath the vertical shadow of the car.

An alternative would be to specify that the air dam must have a vertical surface (within a tolerance) at all points, but that might cause grumbling by folks that use off the shelf air dams with some shape to them today.
 
Ah I see, you're saying even a flat spoiler creates downforce, so a splitter that creates even more downforce must also be legal.

I still don't see why it isn't mentioned. Maybe folks think it doesn't have to be. I just don't trust some steward somewhere to be as level headed.

If the rule in fact used the word splitter, I Wouldn't have to hope some jackass doesn't understand aero.
 
Can we just consolidate the rules with STU or STL? That would just sense. Everyone uses the same rules.
 
Wow.........I want an order of undertray/splitter with a side of "intermediate mounting" and rear wing for desert. Hard to be politically correct in making any kind of statement on the "new" rules.
 
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