GCR 9.1.1.D

[Wright D]

Hello,

I have noticed that a few F1000 manufactures are a bit slack on the GCR rule 9.1.1.D (the 1" deviation rule for the under side of the car). Most seem to violate the rule in the foot box region, where the shadow plate is simply too narrow. Some cars also however violate the rule in an area that is far more serious in terms of generating an aerodynamic advantage. The leading edge of the side pod floors of some cars have a large radius, on the order of 3 to 6 inches. This area of the cars is a bit hard to see in pictures or while walking by, as it is hidden by the barge boards, but is clearly evident when the cars are seen from the lower surface or from the front.

This curvature at the leading edge of the floor is a potent down force generater, as it allows for more high speed air to flow under the car and out the diffuser. This increases the down force dramatically, with virtually no drag penalty. In affect, theses cars have an augmented Atlantic style tunnel inlet that not only physically violates the letter of the 1" deviation rule, but also violates the intention of the 1" deviation rule.

OR--- Am I simply miss interpreting the rule and missing out on a aero advantage?

[Brandon Dixon]

I agree Dustin. I have observed what you are describing. I'd love to be able to make sidepods with a giant radius at the lower leading edge....

[ASRF1000]

Forgive me if I'm wrong, but doesn't GCR Rule 9.1.1.D refer to Formula Ford?, where 9.1.1.H referes to FB?

Am I missing something here?

[Purple Frog]

Welcome to the world of the SCCA GCR... where to find FC regs, you look in FF. Many get confused when discussing, because FB rules stand on their own, but old timers may interpret using FF methodology.
My pet peave about the GCR.

[ASRF1000]

No wonder everyone has difficulty understanding what is and what isn't.

[Wren]

Hello,

I have noticed that a few F1000 manufactures are a bit slack on the GCR rule 9.1.1.D (the 1" deviation rule for the under side of the car). Most seem to violate the rule in the foot box region, where the shadow plate is simply too narrow. Some cars also however violate the rule in an area that is far more serious in terms of generating an aerodynamic advantage. The leading edge of the side pod floors of some cars have a large radius, on the order of 3 to 6 inches. This area of the cars is a bit hard to see in pictures or while walking by, as it is hidden by the barge boards, but is clearly evident when the cars are seen from the lower surface or from the front.

This curvature at the leading edge of the floor is a potent down force generater, as it allows for more high speed air to flow under the car and out the diffuser. This increases the down force dramatically, with virtually no drag penalty. In affect, theses cars have an augmented Atlantic style tunnel inlet that not only physically violates the letter of the 1" deviation rule, but also violates the intention of the 1" deviation rule.

OR--- Am I simply miss interpreting the rule and missing out on a aero advantage?

Yes, there are a lot of illegal sidepods out there. But, it is much, much more acceptable to have an illegal car than to protest someone who is cheating or has designed something illegal. No one wants to put themselves through the public scorn that comes with protesting an illegal car. So, the honest people keep following the rules and the cheaters keep cheating and justifying it to themselves somehow.

I doubt that most people have any idea where their reference area even is.

I don't follow on the footbox though. That is typically in front of the rear of the front tires.

Forgive me if I'm wrong, but doesn't GCR Rule 9.1.1.D refer to Formula Ford?, where 9.1.1.H referes to FB?

Am I missing something here?

The rule in question is 9.1.1.H.3.D

Welcome to the world of the SCCA GCR... where to find FC regs, you look in FF. And because FB derived from FC, look in FF also.
My pet peave about the GCR.

You don't have to reference FC or FF for FB rules. FF and FC are meant to be the same chassis with the differences being in wheels, wings/diffuser, and engine so the rules reference each other to make sure they do not grow apart. No one has struggled with that until recently.

[ASRF1000]

Wren,

Thanks for clarifying that.

[Northwind]

I painted my reference plane area in orange on the bottom surface of the car just to save what could be a real headache for me to explian or outline the mandated datum. This is something that should be a regular check in impound during a weekend. If tech was to varify the reference plane existed any deviations of form may jump out easier for cheaters.

[ASRF1000]

Does anyone have photos or diagrams of what you are refering to? (ie: curvature in what direction, up, down, side to side, etc.) Are you talking about the undertray itself?

I'm trying to completely understand what is in question and its a little unclear to me.

Sorry, I'm better with photos and diagrams. Much more easily understood. I guess I was one of those kids that just looked at the photos instead of reading the articles....LOL

[Wright D]

Basically if I post pictures of the car in question, everyone will know who builds the cars, and I am trying to avoid "outing" anyone.

Wren, by foot box, I mean the cockpit area ahead of the side pods and behind the rear of the front tires....most are wider then their 'T' trays or shadow plates.

Let me whip up a cad pic of what I am talking about.

[Wright D]

Here is a quick picture of the areas I am referring to.

[Wren]

I painted my reference plane area in orange on the bottom surface of the car just to save what could be a real headache for me to explian or outline the mandated datum. This is something that should be a regular check in impound during a weekend. If teck was to varify the reference plane existed any deviations of form may jump out easier for cheaters.

I think it should be a regular check also, but I probably feel like that because Brandon's car is legal and wouldn't have to change the configuration. It is too easy to check the undertray and it never happens. Joe had his ramps at the runoffs and the sprints this year and they were only used for the Atlantic cars and Brandon and Tom when they were being protested. It is not that hard to put a straight edge on the car and measure up with a ruler.

[ASRF1000]

Dustin,

Call me 239-214-2649.

Tried calling you, but wouldn't go through. Thanks

Jon

[Wren]

Dustin,

Thanks for the drawing. I am completely with you on the leading edge of the sidepods.
The cockpit sides is going to be a tougher one to decide on. A long time ago, there was an argument that the Swift DB-1/6 was illegal in FF and FC because of the outward curvature of the bodywork violating the 1" rule because it was not shadowed by anything underneath it. Language was added to the FF/FC rules to clarify what the rule meant:

Mirrors and any primarily vertical bodywork (e.g., cockpit sides)that extend laterally past the outer edges of the floor pan and/
or undertrays are not subject to the reference area restrictions.
Fairings for streamlining suspension pickups are not subject to
the reference area restrictions; however, such fairings shall be
symmetrical about their horizontal axis.

This language was added to the GCR without member input because it was viewed as a clarification to an existing rule, not a new rule. The FF/FC rules certainly don't apply to FB but that may give you some insight into how the rule may be interpreted.

[R. Pare]

From a strictly technical standpoint, what is described in the rule is a "shadow" rule, wherein whatever you can see from below the car is considered the "lower surface of the car (the surface licked by the air stream)". FC had this rule 25 years ago, but it was abandoned for some reason.

The problem with this wording is that if the cockpit sides (and mirrors) bulge out past the shadow plate at some point way above the plate, they should be considered in this measuring.

I know of very few cars that would be legal if the rule were enforced this way, including the Swifts.

The FB rules writers were warned of this interpretation way back at the beginning, but chose to not fix the rule. A simple addition in the wording may suffice in getting rid of the issue.

For the FF/FC rewrite I added in the wording "primarily vertical bodywork" (eg - panels that slope upwards at greater than 45 degrees) and mirrors would not be subject to the 1" rule.

FB has never been subject to the FC or FF rules.

[Mike Devins]

I painted my reference plane area in orange on the bottom surface of the car just to save what could be a real headache for me to explian or outline the mandated datum. This is something that should be a regular check in impound during a weekend. If teck was to varify the reference plane existed any deviations of form may jump out easier for cheaters.

so if you put a straight edge on the area marked it will clear all of the rest of the floor, did you lower that area or add a separate piece of material there to achieve having the reference area lower than the rest of the floor.

[ASRF1000]

I now understand what was being refered to. I was confused about the interpretation and what was being portrayed, but now I understand the "shadow" rule and what areas you were refering to. Thank you!

[Northwind]

Mike,

I did not add or shim the reference plane down from the floor surface. I can swing a straight edge around from this reference plane and not drop below it except for two rivet heads for an access window in the floor pan to drain the motor oil. I consider the rivet heads as my wear strips and are clearly smaller then the defined and allowable wear block dimension. Probably not much aero advantage with these two rivet heads either. I was just too lazy to use counter sunk rivets.

[R. Pare]

I agree Dustin. I have observed what you are describing. I'd love to be able to make sidepods with a giant radius at the lower leading edge....

You can. Call and I'll tell you how!

[John Mosteller]

Dustin,
That is what I noticed when spectating at Pacific Raceways and mentioned in a different thread on here.I had planned to get a decision at the Portland Double National but did not have the time to go to Portland.Here is a cropped section from a photo of one of the Firmans without barge boards that is posted in some of the race photos on this forum that clearly shows the larger radius that I think is non compliant.

The tech guys at an SCCA event don't have the time or the training to know all the rules for all the classes and implement them.It is mainly an honor system and up to us to police our own class.I don't think any of us should feel bad about protesting if it is needed to obtain rules compliance.That is the system that is provided within the rules to address these issues.

[Northwind]

See post #63

http://www.apexspeed.com/forums/show...t=46537&page=2

Some good comparable views of the front pod floor transitions between many makes of cars.

[Jnovak]

I think that these large radii at the leading edge of the pods are definitely not legal. I very much suspect that this will be adequately scrutenized at the Runoff.

Thanks ... Jay Novak

[Purple Frog]

I think the area highlighted in white is what is being discussed.

[urbanimports02]

so it was brought to craig archers attention that the side pod to floor relationship on the new bodywork we did for the stohr was illegal in relation to this rule, but i am a bit confused. i believe it was belling that told craig something of a maximum 1" overhang of the side pod past the edge of the floor, but i can not find this rule anywhere. now with what dustin is saying of the shadow plate not being wide enough, as in you should not be able to see bodywork when looking from under the car, then i guess i see the legality issue of my side pods. the rule however says no point on the lower surface of the car shall be more then 25mm above the reference plane, but my side pods are not the lower surface. they have a sharp under cut under the pod opening that sweeps down and back and then goes down to meet the top of the floor. the floor extends past that lower edge of the pod by about 1.5" like a splitter, so no radius, but the upper part of the pod overhangs the floor and therefor would be seen if looking from under the car. i am fully prepared to make the floor extend further forward as we have no reason to cheat and nothing to gain with the current design, just curious how others interpret this rule as far as bodywork over hanging the floors at a point above the floor. i just whipped up some crude cad renderings of what i am talking about.

[R. Pare]

Jesse:

As the rules are written, that sort of overhang could/would be considered illegal, since the rules states "for the full width of the bodywork" and there is nothing in the rule that exempts overhangs once above a certain distance from the reference surface.

A simple rule fix would be to add in something like "bodywork that is more than 6 inches above the reference surface is exempt from the 1" allowance" or something along that line.

[Rick Ross]

As the rules are written, that sort of overhang could/would be considered illegal, since the rules states "for the full width of the bodywork" and there is nothing in the rule that exempts overhangs once above a certain distance from the reference surface.

If that is the case, it appears that the Firman sidepods may also not be in compliance with the rules. On the other hand, I have not seen a Firman in a while.....perhaps they have already been modified.

[urbanimports02]

just got off the phone with jon lewis, and he spoke with the scca, and yes my floors would be illegal as the rules intent, and i believe it also may be written somewhere is that anything visable from under the car other then suspension, tires etc is considered the lower surface, so yes IF the rule said something like more then 6" above reference plane is exempt i would be fine, but it does not. this does make the firman illegal as the radius at the leading edge is greater then 25mm and therefor a straight edge on the bottom of the car to the forward most part of the side pod would be higher then 25mm. by this interpretation, i believe most of the new stohrs would also be illegal at the rear tire flicks as the tire flicks forward of the rear tire are wider then the floor below. i have not looked closely at this area on there cars, and they may have purposely widened the floors below the flicks to make it legal, so not outright saying theres is illegal, just bringing up more examples. we all have to be responsible for these little grey areas(or some not so grey) so that we are running legal to the letter of the rule. archers car will be made compliant to every rule i can think of before next race, and if anything else is brought to my attention, i will fix that too as we have no intention of cheating. our cylinder head is not milled, our cams are not degreed in, and our combustion chambers are unmodified, we are here to compete with out flirting with any rules. looking forward to a fun weekend at miller and hope everyone leaves there cheater motors at home!!!

[Wright D]

It looks like I interpreted the rules the same way the FB community does. Thanks everyone for all your input.

[Rick Ross]

Jesse,

Fixing your car is the easy part. The hard part will occur when some of your competitors show up at Miller with non-compliant cars.....

[F1000champ]

The most intellegent way to approch this is build your car to be completely compliant. Winning if your cheating isn't really winning, and I as one would find very little satisfaction if I won knowing that my car was not legal.

Let the cards fall on those that don't follow the rules.

This class allows for lot's of innovation and there are always to experiment with new designs. You don't have to cheat and those that do should suffer severe consequences.

Maybe the policing of rules is not as strick as it should be in club racing. But, it should be. It should be up to the series to properly tech all cars to make sure they are in compliance, not the competitors to have to protest.

Protests should be left to on track incidents.

[Mike Devins]

Hey Jon, looks like it is time to do thorough review of the Stohr, it would really hurt to get DQ'd by yourself in your own series.

[urbanimports02]

mike, does this mean you have an idea of something that may be non compliant on jons car? if so, spill the beans. i think this thread could be productive in cleaning up some of the cars that may be illegal without owners knowing. i think if we all come to agreement as to what is and is not compliant on the various cars, then owners and manufactures can correct these items without the need for a protest. i know that after a quick glance of the front splitter piece on the stohr i have in the shop, it is illegal as to what dustin was speaking of earlier, as in the splitter does not actually shadow the above cockpit completely out to its widest point making most stohrs illegal, but a simple fix is to simply widen that piece. as to other guys cheating when we show up to miller, well do what you need to, what ever makes you sleep easier, we are going to make an effort to clean this thing up to the best of our ability.

[Mike Devins]

Sorry Jesse,

Did not mean to infer anything about the Stohr, I was trying to be funny. I know that someone mentioned earlier that the rear tire fairings may cause an issue but I do not really have any knowledge.

really just was sitting hear thinking that how uncomfortable it would be to run a series, rent a car and have it DQ'd.

If we had been sitting around the fire with beer it on doubt would have been funny, was not meant to be a shot.

Since we are in the middle of building a car here now I really appreciate this thread, makes you go back and really "read" the rules for what is and is not allowed.

[Northwind]

I can just hear the resin stir sticks hitting the sides of the cups now. I'm glad this thread came to light. A healthy discussion it has been.

[F1000champ]

Mike,

It's funny you should say that. I have checked over all the dimensions of our car and the car fits within the shadow box as seen from underneath. We were very conscience of that when we designed our barge boards, etc. There was a little trimming we did to ensure its compliance.

However, even though we currently have a 1st Gen Stohr as our promotional car, we will not be running it in 2012, as I see that to be a conflict of interest. I don't think it right to run a series and also have a car/team in the game. I've seen that done before in series we have participated and whether or not its right, the perception can be negative if the owner of the series is cashing in on the financial prizes. There is another team here in Florida that is looking to campaign the car we currently have for the 2012 season.

I know your comment was made in fun. But you're right, it would be very embarrasing to run a series and have a car that was illegal. Believe me, you won't find that in our series.

Jesse, I like your approach to correct any potential illegalities prior to competition. I hope other's have this same attack.

[JohnPaul]

This curvature at the leading edge of the floor is a potent down force generater, as it allows for more high speed air to flow under the car and out the diffuser. This increases the down force dramatically, with virtually no drag penalty. In affect, theses cars have an augmented Atlantic style tunnel inlet that not only physically violates the letter of the 1" deviation rule, but also violates the intention of the 1" deviation rule.

OR--- Am I simply miss interpreting the rule and missing out on a aero advantage?

as I understand that this curvature is illegal by the book, my question is why is it illegal? What is the logic behind this rule? Seems from your description above it is a "potent" down force generator with virtually no drag low cost way to improve these cars. Just wondering why someone somewhere would have the burning desire to make what seems to be a cheap effective and simple mod illegal. Sometimes I feel logic and common sense plays no part in these rules. What am I missing here?

[Northwind]

I'm taking a guess here but I think it is more about saftey. These cars have the ability to develop into a faster package with a bit of time. This rule set is probably to help slow that development and keep it safe. Sure we could make this class really fast with a wide open rule set. But just wait until someone really wads one of these cars up with it's current package. Luckily it hasn't happened yet. It's going to be a mess when it happens.

[F1000champ]

Curvature on the lower edge of the sidepods is acceptible, as long as any portion that forms the shadow box is no more then 25mm higher than the flat reference plane established by the entrant. There can be any size curvature of the lower edge of the sidepods, if such height is within the shadow box created by a structure that is no higher than 25mm from the reference plane (ie: floor).

Anything that can be seen from underneath the car looking up (by a plane purpendicular (sp) to the reference plane) other than suspension, tires, mirrors) between the rear of the front tire and the front of the rear tire cannot be more than 25mm higher than the reference plane.

This is the meaning of the rule by SCCA and will be spelled out more clearly in our official rules.

[JohnPaul]

I'm taking a guess here but I think it is more about saftey. These cars have the ability to develop into a faster package with a bit of time. This rule set is probably to help slow that development and keep it safe. Sure we could make this class really fast with a wide open rule set. But just wait until someone really wads one of these cars up with it's current package. Luckily it hasn't happened yet. It's going to be a mess when it happens.

I don't think that is it as I don't see the cars being faster because of it. It's about downforce and I'd think having more downforce would be make them safer. That's what I mean, where is the logic?

[F1000champ]

I couldn't tell you what the original logic was by the guys who wrote the rules, only that the rules are the rules.

Because we are working to keep our rules as close as possible to those for club racing, we are also following these rules, with the only difference is that we are going to spell them out in more clear and precise terminology, so their can be no question.

Enforcement of them is the key though. The club tech guys have cars in so many classes to examine that I'm sure it's hard to know everything about everyone without taking hours of time to properly tech them. So, you'll probably always see a more lax approach and it will be more up to the competitors to protest.

We have the luxury of having only one class and one set of rules so it makes our job a lot easier. Therefore, cars going through pre-event tech will be thoughly examined and if a car is found not to be compliant, the entrant will be ordered to make it so prior to qualifying. The car will have to be presented to tech again prior to qualifying in order to pass. Pretty simple really.

I'm not sure how many of you have gone through tech in Indycar or IMSA, etc., but its very extensive and its not a debate. Its either legal or not. No question. Its quite a bit different from what I've seen in the few club events that I've attended.

The key is, make sure your car is legal and you won't have any problems.