Understanding the new splitter rule(s)

Here's my issue/question:

I'm reworking my front flares and air dam to match. Trying to figure out what is legal by new or old rule. My confusion arises from whether a part of the "fender flare" that's mounted to and removable with the air dam is subject to the air dam rules wrt being within perimeter.

Right now my (VW Scirocco Mk1) front fenders are stock and the removable air dam is also a mostly stock piece except for an extended lower lip. Quite a bit of the lower front of the tire is exposed to the airstream, the stock front air dam is only as wide as about the tire centerline. This obviously isn't good for aerodynamics, today's performance road cars go to great lengths to shroud tire fronts.

What I want to do is to add a flare lip to the front fender from the axle centerline / highest point of the wheel arch and run this forward along the wheel arch opening down to the bottom of the bumper, which is where the top of the air dam sits. (The stock air dam mounts to the front valance and is well within the shadow/perimeter of the front bumper).

I would then want to flare the rear edge of the front air dam to continue the line of the flare down the wheel arch opening which would serve to shroud the front tire from the airstream. If this "flare" were attached to the front fender it would be flimsy and would basically overlap the air dam. If it is instead attached to the air dam does it have to be completely under the perimeter of the top part of the flare? IE when is a flare a flare and when is it an air dam?

One argument could be that the part above the lower extent of the body is a flare, no matter how mounted. The part below the lower extent of the body can't be flare therefore must be air dam, since flares can't change the side profile of the car (as I read things). So it would be OK to see this flare from above as long as you can't see any part that drops below the body profile....??

I haven't mocked this up yet and it may not be an issue, the air dam mounted part of the flare may naturally hide below the fender mounted part...

Hopefully this all makes some sense w/o pics!

Thoughts?

Al Seim
HP VW Scirocco
 
Yours is a good question Al. I have seen lots of air dams over the years with a flat horizontal ledge in between a lip flare and front of car that was not in the shadow of the bodywork above. My reading was that this was still flare even if physically attached to the spoiler as long as it was 4" below wheel centerline or below. Still, would be great if the board could clarify this before Creighton has a chance to :D
 
Here's a stock bumper from a 99 miata:

3_14.jpg


Here's a pic of a bumper/spoiler on Matt Reynolds car:

MattReynolds.jpg


Jon Brakke's miata bumper is made like this and has been legal for years.

As you can see, the EP version is much, much wider than the stock miata bumper. Clearly so wide that it easily goes beyond the stock bumper's silhouette.

Do I think this is legal? No I do not. You can torture your way to legality by saying that the front piece is a combination bumper/spoiler/pair of front fender flares. Just show my the rule that says you can make all those into one piece.

Incidentally, the Reynolds are really great people and I have nothing but respect for them. If you ever get a chance to meet any of them, I suggest you walk over and shake hands - in my case they came my way first when I needed a hand.
 
Build the flares first. There is no limit on width of the flares. Add the air dam so that it does not violate the shadow rule. MY narrow track Daytona dam tapers as it goes toward the wheel opening to avoid the shadow.

To press the rule further, you could flare the fender with a very wide dive plane up and over the wheel arch and add an air dam under it. IMHO As the rule is written today.

https://www.youtube.com/watch?v=9MQiSqRoHV0 Take the dive planes in the pic and extend the top one to the fender..
 
Protech Racing":ulng97ov said:
flare the fender with a very wide dive plane up and over the wheel arch and add an air dam under it.
Click to expand...

Where does it say you can ad an air dam under a fender?
 
Yes. I can not find a limit to "flare". The flare becomes part of the fender/ bodywork, and thus the air dam may not exceed the shadow under the fender/flare/bodywork.
 
I don't see how Mike's statement is wrong. Quoting the old rule:

An air dam can be fitted to the front of the
car. It must not protrude beyond the overall outline of the
car as viewed from above,

I take this to mean the car as it sits (including fender flares), not the original outline of the car.

There's also nothing in the rule mandating that a fender flare be separate from an air dam, just as there's nothing saying the flare must (or must not) be separate from the fender. It does say that the air dam must be visually separated from the bumper. The Miata pic may fail that test...??

The more I think about it the more I'm convinced that the lower portion of the fender flare can be mounted to the air dam, what's to say that it can't? Following this logic, any part that isn't legal as a flare must be legal as an air dam. Thus any part extending below the stock wheel well cutout/body would need to be "shadowed".

Al
 
Al Seim":1cdwa5gd said:
I'm convinced that the lower portion of the fender flare can be mounted to the air dam, what's to say that it can't?
Click to expand...

Oops.

Fender Flare – An attachment to an existing fender which extends the
fender outward so as to more completely cover the tire within.
Click to expand...
 
I was too focused on Jon's front bumper with the flare attached illegally to the bumper.

I'm seeing your line of thinking on the air dam under the flare, but I'd be surprised if they let that go.

Just remember- you cannot attach the flare to the bumper, according to the definition of a fender flare.
 
Hmm -

Note to self - read glossary before posting.

But -

The side part of my "air dam" (note strategically placed quotes) does in fact mount to my front fender (stock location though it may not matter). So if I choose to call the rearmost 4" of the air dam "fender flare" then it is in fact attached to the existing fender. You can call this rule torture but I'm not sure.

I'm certain that most top prod cars have wide front air dams that join with the flares and do a good job of shrouding the front tires. I'm equally sure that the air dam is allowed to hide beneath the flares, or this would not be possible. Where I'm a little iffy as stated is exactly where a flare stops and an air dam starts.

Also - I'll agree that the flare must be attached to the fender. Doesn't say it can't also be attached to bumper or air dam.

Al
 
It's only fun to a point arguing about this stuff. Honestly it's the SCCA rulebook, and we know that there's an unwritten set of things you can get away with. THere's also certain cars who have found a torturous way to make what they want legal - and I doubt there's any interest in a rewrite of these rules for that reason.

Here's the flare rule:

The exterior contour of all wheel openings may be flared.
The fender/wheel opening or any other part of the body
forming the wheel opening, when viewed from the top
perpendicular to the ground, must cover the portion of
the tire that contacts the ground while the car is at rest.
The flaring of the exterior contour of any wheel openings
may not alter the basic body configuration or change the
wheel opening size, location or shape when viewed from
the side.
Click to expand...

So in fact, if you consider the bumper part of the contour of the wheel opening (and only then) the bumper may also be flared.

The interesting part of that one is, the shape of the miata front wheel opening has clearly changed on Jon Brakke's fender.
 
Useful to debate sometimes, I had missed the attached to fender bit. Thanks Bill for pointing that out.

I'm trying to come up with an easy / light / simple way to better shroud the front tires from the airstream. Legally and effectively! Not trying to torture the rules into adding dive planes etc. Can't balance that stuff with rear downforce anyway.

I have a feeling that a lot of existing well prepped Prod cars may be in the grey zone at the air dam / front flare interface, depending on exactly how the rules are interpreted.

Al
 
blamkin86":2cemyk7a said:
...As you can see, the EP version is much, much wider than the stock miata bumper. Clearly so wide that it easily goes beyond the stock bumper's silhouette.
Do I think this is legal? No I do not. You can torture your way to legality by saying that the front piece is a combination bumper/spoiler/pair of front fender flares. Just show my the rule that says you can make all those into one piece...
Click to expand...

I wrote a letter when I first got my Miata and was playing with the bodywork. I asked that in the "bumper" section of the rules that it allows for flaring, so that it can match up with the fender. Instead the rules now states: The exterior contour of all wheel openings may be flared. So instead of having a separate bumper section having another "flare" allowance, "fender' was replaced with "wheel opening". So I think it's legal.
 
In the middle of building an EP car here and this is one of the most confusing sections of the rules for me.

I've just bought an expensive flare and front bumper/air dam kit that I am convinced is legal in the since the width of the flares OUT from the car is pretty damn wide, but nothing worse than most pictures I've seen. I've matched the flares up with the existing fenders and it looks to me that the wheel opening size, location and shape is basically the same (a 1/4 or 1/2 misalignment on shape in a few spots that I can fix).

Where I'm lost is on two things:

1. The kit I bought has a one piece front bumper and air dam, all fiberglass. I know I can replace my bumper cover, so I think I'm ok wit the fiberglass bumper cover. I know I can have an air dam that stays within the body silhouette (after flaring correct?). So it sounds legal so far. BUT -- do I literally have to cut and reattach the bumper the to the air dam portion of the fiberglass, because my bumper was a separate piece before? That sounds kind of silly but that is how I read the rule.

2. Like the discussion above, my bumper is flared outward a bit, to match the fender flare. It effectively extends the body silhouette as a result and makes the rest of the air dam legal. Based on the discussion above, it looks like the conclusion here is that is legal?

Thanks guys!
 
9.a.3
The exterior contour of all wheel openings may be flared.
The fender/wheel opening or any other part of the body
forming the wheel opening, when viewed from the top
perpendicular to the ground, must cover the portion of
the tire that contacts the ground while the car is at rest.
The flaring of the exterior contour of any wheel openings
may not alter the basic body configuration or change the
wheel opening size, location or shape when viewed from
the side.

If the bumper forms part of the wheel well opening, then you are fine with flaring it.
 
+1 On Chris Statement. IMHO... if you look at the noses of most of the cars, they often have a line drawn where the bumper lives/lived etc. You certainly do not have to cut it apart. Anything to separate the bumper visually seems sufficient.
The rules and real world are not exact.
 
MattReynolds.jpg


Here's a bumper that's been through the runoffs tech shed many, many times on many cars.

It's a one piece bumper/splitter/airdam/fender flare.

There's no attempt to try and separate the individual parts.
 
You must log in or register to reply here.
Back
Top