It’s not defined in the new rules. So which of these would be legal (assuming they don’t extend beyond the bumper)?
What's a splitter?
Ranger
#2
I don’t see any element of the 4 that would make it illegal. Bad idea, probably. Illegal, no.
EdP
#3
The rule does say “splitters are prohibited”, so I think 2-4 are illegal, and 1 (using the EVO3 splitter) would just be wrong.
Patton
#4
Kyle, don’t know why I’m not on the Carter Hunt distribution list for rules, however the aero stuff shown kinda falls under the heading of first “learn to drive.”
No opinion.
RP
Ranger
#5
Now that I’ve gone back and actually read the new rule on splitters, I better understand your point Kyle and retract my post above. It looks like splitter could use some further defining if we to understand precisely what is illegal. Certainly any horizontal piece of material that sticks out of the bottom of the air dam is going to be called a splitter. The early OEM air dam lip is prob 60deg from horizontal. So somewhere, I guess, between those two is where a air dam lip becomes a splitter.
The rule says that the air dam can’t go rearward beyond the “most forward part of the fender opening”. That’s the same language that has been with us for a couple years and is generally interpreted to mean that you can have an undertray that goes back to the forward edge of the wheelwells. But as soon as your undertray goes forward of your air dam, it becomes a splitter.
It’s a new rule and sometimes they take some extra massaging. No big deal.
cosm3os
#6
[quote=“Patton” post=69789]Kyle, don’t know why I’m not on the Carter Hunt distribution list for rules, however the aero stuff shown kinda falls under the heading of first “learn to drive.”
No opinion.
RP[/quote]
The new rule is under the tab to the left.
cosm3os
#7
[quote=“Ranger” post=69790]The rule says that the air dam can’t go rearward beyond the “most forward part of the fender opening”. That’s the same language that has been with us for a couple years and is generally interpreted to mean that you can have an undertray that goes back to the forward edge of the wheelwells. But as soon as your undertray goes forward of your air dam, it becomes a splitter.
It’s a new rule and sometimes they take some extra massaging. No big deal.[/quote]
Under that interpretation, then, 3 and 4 would be legal as long as the front does not protrude past the bumper, and the rear doesnt go past the front of the wheelwell opening.
It is a big deal because we have about 6 cars being built right now in the MW and my guys would like alittle direction.
EdP
#8
3 and 4 can’t be legal. you have to read any rule in the way that makes all of its provisions make sense. To me, “splitters are prohibited” means 3 and 4 are clearly NG.
FWIW, here are two definitions from the BMWCCA rules:
Splitter – An aerodynamic piece that is parallel to the ground and attaches to the bottom of the front bumper cover or air dam.
Spoiler – A panel attached to the body of a car at the front, intended to alter the airflow around or under that end of the car when in motion.
Again, FWIW. But I think these definitions are common sensical
Ranger
#9
[quote=“cosm3os” post=69792][quote=“Ranger” post=69790]The rule says that the air dam can’t go rearward beyond the “most forward part of the fender opening”. That’s the same language that has been with us for a couple years and is generally interpreted to mean that you can have an undertray that goes back to the forward edge of the wheelwells. But as soon as your undertray goes forward of your air dam, it becomes a splitter.
It’s a new rule and sometimes they take some extra massaging. No big deal.[/quote]
Under that interpretation, then, 3 and 4 would be legal as long as the front does not protrude past the bumper, and the rear doesnt go past the front of the wheelwell opening.
It is a big deal because we have about 6 cars being built right now in the MW and my guys would like alittle direction.[/quote]
I hear you but as a Regional Director you’re part of the decision making process. We’re just the rank and file. Well, not me of course. I’m now the National Director of Morale and Beer Selection. That’s hot off the presses btw. I just made that mod of the website Contacts a couple hrs ago.
jlevie
#10
In my opinion, based on the definition of a splitter (look it up on Wikipedia), all four of those are illegal. The first two examples have what functions as a splitter as a part of the airdam. The latter two have separate splitters.
If it looks like a duck, quacks like a duck…
cosm3os
#11
[quote=“EdP” post=69793]3 and 4 can’t be legal. you have to read any rule in the way that makes all of its provisions make sense. To me, “splitters are prohibited” means 3 and 4 are clearly NG.
FWIW, here are two definitions from the BMWCCA rules:
Splitter – An aerodynamic piece that is parallel to the ground and attaches to the bottom of the front bumper cover or air dam.
Spoiler – A panel attached to the body of a car at the front, intended to alter the airflow around or under that end of the car when in motion.
Again, FWIW. But I think these definitions are common sensical[/quote]
I agree with you that 3/4 should be out, but we shouldn’t be looking to wikipedia, CCA rules, or common sense to interpret our own rules.
EdP
#12
oh, I think we’ll survive. 
this actually seems like an easy one to me, except maybe for that EVO spoiler in the first picture. but I’m pretty sure there are other provisions in our rules that would preclude its use. heck, that spoiler wasn’t even available on US M3s.
JeffN
#13
As I’m the one who brought this up, I figured I’d chime in. I was exploring my options for a replacement bumper to keep around for a back up and thought a fiberglass one could do the trick. I like the idea that I wouldn’t have to spend $200 on brake ducts and just use the bumper’s built-in ducts instead.
Let’s assume that the spoiler doesn’t extend past the profile of the bumper. The flat bottom is the questionable part I suppose, but it’s mostly there just to keep the bumper from flopping around in the wind.
Ranger
#14
[quote=“cosm3os” post=69792][quote=“Ranger” post=69790]The rule says that the air dam can’t go rearward beyond the “most forward part of the fender opening”. That’s the same language that has been with us for a couple years and is generally interpreted to mean that you can have an undertray that goes back to the forward edge of the wheelwells. But as soon as your undertray goes forward of your air dam, it becomes a splitter.
It’s a new rule and sometimes they take some extra massaging. No big deal.[/quote]
Under that interpretation, then, 3 and 4 would be legal as long as the front does not protrude past the bumper, and the rear doesnt go past the front of the wheelwell opening.
It is a big deal because we have about 6 cars being built right now in the MW and my guys would like alittle direction.[/quote]
Re. under that interpretation. No. You’re looking at my paragraph that discussed how a splitter can also be an undertray as if that was the only requirement in defining a splitter. The paragraph before discussed the common sense definition of a splitter being a horizontal piece under the air dam sticking out forward. That would make 3 and 4 illegal.
Re. it’s a big deal. Only if one buys into the idea that they are useful. Just because some drivers with good skills had some success with splitters doesn’t make splitters a good idea. Correlation is not causation. We race cars with net rear aero lift. It makes no sense to move the center of aero balance even farther forward by adding front downforce.
cosm3os
#15
oh, I think we’ll survive. this actually seems like an easy one to me, except maybe for that EVO spoiler in the first picture. but I’m pretty sure there are other provisions in our rules that would preclude its use. heck, that spoiler wasn’t even available on US M3s.[/quote]
If its “easy, except”, then its not easy. Where’s the rule that says it has to come on a US car, M3 or otherwise?
Just stimulating the discussion . . .
JeffN
#16
[quote=“cosm3os” post=69800]
If its “easy, except”, then its not easy. Where’s the rule that says it has to come on a US car, M3 or otherwise?
Just stimulating the discussion . . .[/quote]
If it’s aftermarket, it doesn’t come on any car! 
EdP
#18
[quote=“JeffN” post=69798]As I’m the one who brought this up, I figured I’d chime in. I was exploring my options for a replacement bumper to keep around for a back up and thought a fiberglass one could do the trick. I like the idea that I wouldn’t have to spend $200 on brake ducts and just use the bumper’s built-in ducts instead.
Let’s assume that the spoiler doesn’t extend past the profile of the bumper. The flat bottom is the questionable part I suppose, but it’s mostly there just to keep the bumper from flopping around in the wind.[/quote]
Fiberglass would be a really bad idea. even if legal, it won’t survive much bumper-to-bumper contact, which is very routine. also, what you have there is a lightweight cover, without the core or solid attachment points of the OEM bumper. it’s far from a plug-play installation. PS, I don’t think replacing the factory bumper with a FG cover would be legal.
EdP
#19
Also:
9.1.1. All cars in this category shall compete as equipped by the manufacturer, except as allowed
by these regulations.
BMW didn’t equip any 325s with EVO spoilers, AFAIK.
jlevie
#20
[quote=“cosm3os” post=69796][quote=“EdP” post=69793]3 and 4 can’t be legal. you have to read any rule in the way that makes all of its provisions make sense. To me, “splitters are prohibited” means 3 and 4 are clearly NG.
FWIW, here are two definitions from the BMWCCA rules:
Splitter – An aerodynamic piece that is parallel to the ground and attaches to the bottom of the front bumper cover or air dam.
Spoiler – A panel attached to the body of a car at the front, intended to alter the airflow around or under that end of the car when in motion.
Again, FWIW. But I think these definitions are common sensical[/quote]
I agree with you that 3/4 should be out, but we shouldn’t be looking to wikipedia, CCA rules, or common sense to interpret our own rules.[/quote]
Well you have to have a definition from some place. I like the Wikipedia definition because clearly describes what a splitter does. Any thing at the bottom of an air dam that produces that same aero effect is a splitter.