Bumper/ splitter clarification round 2

Protech Racing

Well-known member
Do we need less subjective wording for the bumper rule? Regarding size,shape/profile vs the stock bumper?
1)How much bigger or smaller can the replica be and still be legal? IE tolerance value?
2) How far in front of the grill can the replica be VS the stock piece? and tolerance value? Can I make the nose 3 in longer?
3) Overall shape tolerance? Can I make a formerly straight bumper rounded?
4) How far infront of the bumper can the splitter be out of the shadow? What is the actual tolerance?

I would hate to get tossed or bitched about by having a bumper /nose Out of range or the spirit of the rule. Daytona is pretty fast and many will look to have nose panels @ full aero values. IMHO.

PS, my questions are based upon the GCR glossary for "replica." exact or similar.
How close is similar? 1in, 2in, 1/4 in
 
2011 GCR hard copy

With reference to your questions, 1, 2, and 3. Look up the word replica in the GCR glossary.

With reference to your question 4, the word spliter is not used, the word air dam is used and the air dam MUST (same meaning as SHALL) not protrude beyond the overall outline of the car when viewed from above.
 
I would hold, you cant do any of the things you suggest.
I am not crazy about the term "similar" in the definition of replica,
but if you don't want to get tossed. Go with a component identical,
if the bumper is integrated into the bodywork. If its not integral,
the rule goes one step further to state "appearance remains as stock".

If there is a change warranted, it is only to remove the word similar from
the definition of replica.


Bumpers that are integrated into the front or rear bodywork,
can be replaced by replica components of an alternate
material. The energy absorbing bumper components
behind the front or rear bumper cover can be removed.
Bumpers which are not an integral part of the body can
be removed or replaced by components of an alternate
material, provided their appearance remains as stock.

Replica – A component identical to or very similar in appearance and function
to the original which it replaces.

Stock – In the exact same state or location as supplied by the original
manufacturer.
 
I always wondered how far forward can one bring a spoiler/air dam/spliter on a car that cam stock with a factory steel bumper and factory bumperetts??
 
Not any further forward than the outline of the car when viewed from above.
If a bumper is there, it is part of the car. The splitter which would be part
of the air dam must follow the contour of the bumper (car). If there is a "bumperette"
then I would expect to see a bump out in the splitter following that contour.
The rule doesnt say outline of bodywork, it says car.

Assuming all else is legal (bumper, fender etc). A carpenter square flat on the ground, pushed up against
the car in any position must hit fender, hood, bumper, bumperette, valance, TOW HOOK :wink: , CAR, before
it touches any splitter or airdam. That was always my check.

Air Dams: 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, or extend aft of the forward
most part of the front fender opening (cutout), and must
not be mounted more than four inches above the horizontal
centerline of the front wheel hubs.
 
I can tell you now that all of this will be a daily compliance item at the Runoffs. If you have something that is questionable, you should be prepared to present proof that it is compliant.

If you can't present proof, then be prepared to remove/fix or convince the stewards it is ok.

I will use a blumb bob to check for within body work. Pay close attention to the sides. That is where most folks have a problem.

A lot of speed can be lost at Daytona with ill fitting body panels. Need to bring a slick car to win. Even decals in the wrong places will hurt.
 
Can we agree that within 1/2 in of stock equals "similar"?
That includes ;above viewed profile designating bumper outline /ark.
Front viewed thickness
front viewed height RE to headlight holes or core support
Total length
Total extension from grill face or core support .
If so, I will put in a letter for clarification.
MM
 
Protech Racing":18am7i2s said:
Can we agree that within 1/2 in of stock equals "similar"?
MM

Where does it stop. How about if my replica bumper sticks out 3 inches from stock, and I have 3 inch more splitter than others in the class. Fair ???
 
Why would you say this ? What is the relevance?
How is 3 in equal to 1/2 in? IMHO 1/2 in would be very close to the same in a visual reference.
Much more, and the spirit of the rule is lost.
 
If a 1/2 inch variance is acceptable, why not go for the full inch?

And in a few years we can ask for a 3 inch variance.

Not sure that longer, and definately not wider, are are better at Daytona. Wouldn't want to increase drag on a Prod car.

Adding more splitter for more downforce needs to be balanced with more rear downforce. Who can run additional rear spoiler?
 
Agree 100% John.

Mike, talking rules migration, nothing more or less. I'm sure you understand why the limited prep rules came about.
 
Biggest problem would be finding out the dimensions to start with. Each region needs a supply of bumpers at tech. I've only seen my bumper in pictures. I like that Mike is try clarify the rule but I think were ok, tech may just have look at some cars a little closer. I believe some slipped thru the cracks and we need to tighten that up a little.
Chuck
 
c mathis":15p5cgkg said:
Biggest problem would be finding out the dimensions to start with. Each region needs a supply of bumpers at tech. I've only seen my bumper in pictures. I like that Mike is try clarify the rule but I think were ok, tech may just have look at some cars a little closer. I believe some slipped thru the cracks and we need to tighten that up a little.
Chuck

No reason for the Region to have one. If your bumper got protested, and its not stock (and no OE piece to compare it to) I would expect it to be removed in impound and sent to SCCA for comparison - they will have to source an OE part.
 
Don't think SCCA would have parts for older cars to check against and once got protested in ITA and they sent my cams to Denver to check and VW wouldn't give them the cam specs. A month later they I was probably legal and sent them back.
Chuck
 
The GTL rule is simple and easy to enforce when it comes to splitters and it's the same for everyone.

• GTLite: a front splitter may extend up to 2 inches.

Simple, 2" of flat surface.
 
Replica – A component identical to or very similar in appearance and function
to the original which it replaces.

Similar- resembling without being identical.
alike, (much) the same, indistinguishable, almost identical, homogeneous, homologous;

As I said, not crazy about the use of similar. The alterantive is
1. Require exact "as Stock" alternate material bumpers.
2. Do not allow the replacement of bumpers with alternate materials bumpers.

There can be no measurable "allowance" from stock. With the complex shapes of some bumpers,
it just isn't resonable to do so. Making a bumper a 1/2 inch, 1/8 inch or 3 inch larger
in order to make your splitter larger under the guiles of its similar is a totured interpretation.
The inclusion of "similar" is to allow amateurs to reproduce bumpers that are not identical in every way.
If someone chooses to push the limit of the rule as it is written then, with any rule, they should
be willing to defend it in the courts. If I were to run an alternate bumper, I would make damn sure
it was "very similar", not just similar, but "very similar".

If you don't like similar, and want a number.
Be prepared to take it off, or duplicate your stock one in every way shape and form, because that
is the end result of a clarification.
 
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