Understanding the new splitter rule(s)

The orange stripe is your "attempt" to separate. ;)

(I wondered why my RX7 front end had a black Sharpie outlining the "bumper" until these splitter rule threads came up...)
 
Matt93SE":y6feq19x said:
The orange stripe is your "attempt" to separate. ;)

(I wondered why my RX7 front end had a black Sharpie outlining the "bumper" until these splitter rule threads came up...)
Click to expand...

Within past air dam rules the following words were written within the rule. :mrgreen:

"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."
 
Why is this part of the rule even there, especially when integrating all of the more modern cars with one piece front fascias? Is this something that should go away?
 
Really dont need large parts of the rule.
Also the airdam rule restriction of 4 in above the hubs makes no sense. I put one on the rental car yesterday and had to use the "intermediate" panel to attach the air dam to. Effectivly extending the air dam about 12in above the hubs, up to the grill . I may have to label everything with a majic marker.
The shadow rule is fine over the front of the car but really gets lost around the sides where the fenders/bumper/ flares/ air dam blend into the wheel opening.

Reality of air flow /drag is that the total sq in of involvement determine drag and any downforce. Extending the front splitter does indeed make down force and can be controlled with the shadow rule .
As long as the air control does not cover the stock grill and headlight areas any aircontrol inside of the shadow rule on the front facing sections should be legal IMHO.
The sides/wheel opening, can take care of it self, either allow dive planes or not. FWIW dive planes could also be called fender flares in the GCR .
 
Brett W":3jco1yhq said:
Why is this part of the rule even there, especially when integrating all of the more modern cars with one piece front fascias? Is this something that should go away?
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David Dewhurst":3jco1yhq said:
Matt93SE":3jco1yhq said:
The orange stripe is your "attempt" to separate. ;)

(I wondered why my RX7 front end had a black Sharpie outlining the "bumper" until these splitter rule threads came up...)
Click to expand...

Within past air dam rules the following words were written within the rule. :mrgreen:

"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."
Click to expand...

Maybe I should have wrote, within past, 2011 GCR and previous air dam rules the following words were written within the rule and these words no longer exist within the new rule. :think:
 
We need a new simpler rule that can cover 55yrs of cars.
How about; "Air control can not cover the stock grille openings, the stock head light bezels or lenses, may not protrude beyond the forward shadow of the stock bodywork.
Air control may join the wheel opening flares. The max width of all air control and body work will be 2in wider than the wheel edges. Holes may be cut as needed in the air control panels. "
This wording should continue to allow the Bugeye noses, the Spit noses and the more current Yaris nose. IMHO. This also reduces the tech time and subjective interpretation of the current rule. Tech is merely a T square placed along the front of the car , tech stops as the front of the car bends around the sides.
Results may be a small splitter along the nose and around to the wheel opening at less than 2 in outside of the wheels, Small canards up and over the wheel arch( that are now also legal) as "flares" .
 
Protech Racing":1l7xyi7j said:
We need a new simpler rule that can cover 55yrs of cars.
Click to expand...

How about a modified version of the GT rules? Seems pretty straight forward. Obviously any of the older cars are grandfathered, not sure there are many folks building new Sprites and MGs for Production so they really wouldn't apply, but if updated could just follow the new rule.

A spoiler may be fitted to the front of the car. It shall not
protrude beyond the overall outline of the car as viewed from
above except as follows:
• EP: a front splitter may extend up to 2 inches.
• FP: a front splitter may extend up to 1 inches.
• HP: a front splitter may extend up to 0 or 1 inches.
In all classes, the spoiler shall not extend aft of the forward
most part of the front fender opening (cutout), and shall not
be mounted more than four (4) inches above the horizontal
centerline of the front wheel hubs. The spoiler shall not cover
the normal grill opening at the front of the car. An intermediate
mounting device may be used on cars whose front bodywork
is above the four (4) inch minimum. Openings are permitted
for the purpose of ducting air to the brakes, radiator, airbox
and/or oil cooler(s); equal openings may be placed in the
standard lower front panel directly behind openings placed
in the spoiler. When bumpers are retained, the spoiler and
bumper shall appear to be two separate parts. Spoiler “pans”
are only permitted forward of the leading edge of the front
wheel openings and shall be flat and follow, but not exceed,
the line of the front fender/spoiler bottom.
Click to expand...

Do we care if there are two "separate appearing" pieces for the airdam and front bumper? Why was this in there to begin with? To deal with some older cars?
 
I dont think that we want splitters or the 4in to hub rule. I am trying to write a letter that covers the existing cars and designs. not make a new design. KISS
Allowing splitters is rule creep . Not my intention .
 
Protech Racing":2o13kshf said:
I dont think that we want splitters or the 4in to hub rule. I am trying to write a letter that covers the existing cars and designs. not make a new design. KISS
Allowing splitters is rule creep . Not my intention .
Click to expand...

We already have splitters, they just don't stick out now past the bumper. I assume the 4in rule was to keep people from putting a wing on the front of the car. We could probably dispense with that as well. That makes the rules even easier.
 
4" rule was to keep builders from covering up the whole front of the car with an air dam. Nobody even knew what a splitter was back then. 4" + is way high up on a full prep traditional sports car sitting barely 1" off the ground. I can barely imagine just how ugly some cars old and new could end up looking without the 4" rule.
 
Agreed that we do have splitters. Just saying that the splitter cannot extend outside the shadow of the bumper is enough.
 
Silly VW guys, you corner faster on four wheels than three. :p

I have always eye'd the VWs with a little envy, you could put a pretty serious splitter under the front of those huge bumpers. However I wouldn't trade all the other issues you have to deal with for a slight aero advantage.
 
The issue I see is that the modern cars have a seamless front end, the air dam just continues the smooth lines to the ground, where as the old cars with separate bumpers have a lot more crap for the air to interact with.
A reasonable rule should allow the older cars to more closely resemble the new cars. Getting rid of the 4 in part of the rule would indeed allow the air dam to be very near the grille openings on the old cars. much like the Honda CRX,the Yaris, Mini.
The next part of the rule has to deal with the "shadow" along the sides of the car. IMHO the best way would be to mandate a max body width rule in correlation with the track rule , and remove the "shadow" stipulation regarding the sides of the car. The shadow is fine across the nose and keeps all of the current cars/designs happy.

The tech guys looked at my car@ Homestead for quite a while,. but walked away when asked for their thoughts concerning any legality issues. Very disappointing for me as a customer for sure, and I would be re.ally pissed if it was tossed without taking the time to discuss it before hand. when the opportunity existed.
MM
 
You are right Mike that with many of the older cars (not the MGs) the bottom of the car aero is terrible and it is best just to keep the air out of there but....... I also think the splitter represents only a very slight aero advantage and not a downforce advantage. I mean if you have to put the bumper over it then the air is pushing as much up on that as it is down on the splitter, right? If you guys want to argue the flare thing go for it I just don't see anything wrong with the 4" rule. It keeps prod cars looking like prod cars and not claimer class dirt track POS imho.
 
The 4" rule is an issue for my "transition" era car. It has a larger plastic bumper cover that is integrated into the bodywork, but that ends about 1.5" from the wheel opening. This means when I flare the fender to cover the front of the tires, and I design a front air dam wide enough to meet that new fender profile, I am left with an awkward inch or two gap above the airdam where the stock width bumper sits, and the air dam is not allowed to cover. This will require some thought and creativity to accommodate in the fender/air dam design.

However, if the bumper just went back a touch more, and formed the front of the wheel opening, I could flare it to my hearts content, and make a sensible shape out of it.

As it is with the current rules, I am more likely to end up with a Chump-esque front corner than a properly fitted flared wheel opening. Allowing bumpers to be flared to fit the already allowed flared fenders, or allowing the air dam to go above 4" from the axle center line would allow this to look much better.

Here is the flared fender shape.
Left%20Bondo%207_zpsejydttgt.jpeg


Here is the bumper on the car.
vwracecar3.jpg
 
I'm with you Chris - the rule should be written so that all prod cars can have the same bumper/fender combination as the miata.

IMHO.
 
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