F-1000 Rear Diffusers
In response to questions about the rear diffuser rule in F-1000, and how it is interpreted in FC, Dave Gomberg examined each FC on pre-grid yesterday. Every single one of them started the diffuser at the leading edge of the rear tire. Not one exploited the 1" rule. Therefore, I suspect that the diffuser rule in F-1000 will stand as written.
Stan
Stan Clayton
Stohr Cars
Sounds good. Looking at some pics I don't believe mine starts early...
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
sad and curious news
Stan-
what does looking at existing FC diffusers have to do with anything that's relevant to F-1000 rules??? I thought someone pointed out on this forum that F-1000 wasn't FV or FF or FC or FM or .............. the 1" flat bottom rule in the current draft F-1000 rules is a paraphased version of Richard's suggestions; it's the only objectively verifiable part of the draft bottomside aerodynamics rules package!! does everyone understand flat and level are two distinct/different words???
are the obvious objective verifiability problems (that have been repeated pointed out) with the "diffuser" and "venturi tunnel" language in the current draft going to be addressed or not?? if not, I guess we're all left to wonder who was too smart, or too proud, or working an agenda at cross purposes to objectively verifiable rules, or .......................
as an aside, I find it sad that something so technically simple has been allowed to fester so long and is now being handled by a press agent within the contex of the joy, excitement, celebration of the RunOffs........................................... ......
Art
artesmith@earthlink.net
Last edited by Art Smith; 10.10.06 at 2:08 PM.
Point of History
The rules for the pro F2000 and the rules for similar cars in Europe called for a 1 cm deviation not 1 inch. When I designed the Citations I always built to the pro rules as did every one else.
I did run a 6mm (.6 cm), one inch wide rub strip the full length of the side pod outer edge. That is only legal in SCCA. But some person could interpert the rub strips as forming a tunel or venturi and that would be illegal.
I suggest that now that the Stohr is out, the rules committee sits down and rewrite the rules to make sure that the Stohr and a current FC are legal in the proposed F1000.
I just checked my three diffusors:
1) Pennon Polecat for RF98 and up - upward slope starts at the front of the rear tires
2) Stock RF99 - upward slope starts at the front of the rear tires
3) Stock RF96 - upward slope starts about an inch forward of the front of the rear tires
So I guess I was wrong on a previous post...
A quick glance at the Stohr makes me wonder about the sidepod height rule. The floor under the sidepod extends outwards past the sidepod at the maximum sidepod width location. I don't believe that was our intent - you'd have to ask Sean O or Mike B.
But Steve is right - perhaps someone should start identifying rules issues.
Originally Posted by Art Smith
Because if all of the current FC cars exploited the 1" rule then the F1000 rules may have been changed to accomodate conversions.
Who cares if the bottom of the car is level? I like having the ability to adjust rake. As long as its flat than the angle of that flat bottom should be up to the racer.
I really don't think talking about diffusers, F1000, or anything else takes away from the runoffs... are you just trying to ruffle feathers?
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Rob,
Am I missing something? The Stohr sidepod is well over 20 cm high -- more like 30-40.
I don't know that we need to "rewrite" the rules. OTOH, bona fide issues (like the foot placement rules) will be happily addressed.
Steve, from a casual glace at the Stohr, I would be confident it could pass the most stringent flat bottom test applicaable to a race car. It appears to have been molded on a piece of glass.
Art, I know that 'diffuser' and 'venturi section' are not defined in the GCR glossary, but each term has appeared in relevant class sections of the GCR for more than 30 years, and anyone who cares to knows what they mean. You may not like that, but that's the way it is.
Stan
Stan Clayton
Stohr Cars
Stan, most of the time I generally agree with your posts. On this topic, though, I'm not sure why we wouldn't want to avoid terms in the GCR that are open to different interpretation. I'm probably oversimplifying the issue, but can't the definitions be put into the GCR? If a clear definition cannot be determined for putting into the GCR, then how should we expect all tech inspectors to clearly know what is or isn't a venturi or diffuser?
If you leave them open to interpretation, then you are almost forcing manufacturers to push the envelope past what most of us would consider legal.
IMO, if you can define it, please put it in the GCR. If you can't define it, maybe there shouldn't be references to it.
I don't feel overly strongly about this, but I do understand the reasons people are requesting clear definitions for terms referenced in our rules.
Racer Russ
Palm Coast, FL
What Rob is refering to is the section of the floor that appears to extend beyond the sidepods. In our discussions we thought that requiring a min sidepod height across all floors would prevent people from building huge uncovered floors to produce downforce... that a min sidepod height would cause drag which minimized the gain...
I have to also agree w/ Russ here- if what Art, Richard, etc are all having issues with is the lack of clear definations than lets provide one. Just saying its the way we have done it in the past is really not a great justification. I'm not really sure why its so hard- the bottom of the car had to be flat! You are free to do what you want past the rear tires and before the fronts! Stohr seems to have it figured out based on the reports from Kansas...
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Yes - thank you Sean. That is what I meant.
So is the next step to build a car with sidepods the same width as a DB1 but have a floor across the max width of the body? Can I use the stock RF99 sidepods and extend the floor to the allowed maximum width?
Our intent in the rules package was to prevent this. In my opinion, we need a rule providing a maximum distance between the edge of the sidepod and the edge of the floor.
This, of course, is what Steve is alluding to...
Rules Intent
F1000 was a class started to allow outdated FC cars to be converted to MC power. Period. Anybody that says different is off their rocker. The original intent of the rules was for this purpose, but during the process of getting the rules into an official form, some things got changed (some for the good....and some for the bad).
If there are ambiguous areas of the rules guys we need to fix it. Maybe not this second...but let's not let things go for years when there are a hundred cars and changing would be difficult.
As far as Lee's design goes....I think there are some areas where he has pushed the limit on the rules to try to maximize downforce....but that's the way it goes. Truthfully, the car hasn't seen the track yet so the jury's out on whether some of the ideas will work or not. Time will tell.
My only hope is that the rules will be maintained in a form that will allow the converted FC cars to be competitive....otherwise the original intent of the class has been lost before the class even gets started....and that would be bad.
FYI......I'm hoping to have some images pulled from SolidWorks today and I'll try to get them posted here, on the SR forum, and on our website. They won't be perfect, but at least you'll see what we're working on.
Matt Conrad
Phoenix Race Cars, Inc.
Floor vs. Sidepod
It is my understanding is that it was the intent of the rules to keep people from running minimal sidepods and running a max-width floor....it just didn't get put into writing exactly that way. The way it is written now....do you even have to have sidepods???
For what its worth....my 1990 Van Diemen FC had minimal sidepods and a wider aluminum floor (I think it probably stuck out 6" on each side).
Matt Conrad
Phoenix Race Cars, Inc.
Stan
Stan:
I take it that the unsculpted section of the side pod extends to the full width of the bottom. It appears that not only do we have to worry about the shape of the bottom of the car but we will have to figure out how to measure the height of a surface perpendicular to the bottom at the outer limit of the bottom.
In any event I apologize, and stand rebuked and chastised for ever doubting that those who wrote the rules could not build the car to fit the rules.
In any event, if this class catches on, I think we will see more original formula car engineering as F1000 develops than we have seen in years. Will this class get its inspiration from F1, F3, Indy cars, be a continuation of FC, or become something entirely unique? It should be great fun to watch and participate.
I am probably missing something, but I can't find a spot in the rules where it specifies that the minimum sidepod height must be maintained to the maximum width of the car.
Cheers,
Rennie
Rennie,
You're right. It doesn't. But that was our intent.
Rob:
I'm not questioning your statement of intent, but I just went back and looked at all of the previous drafts (going back to the very first submission from the ad hoc to the F/SRAC) and there was never any indication of this in the "Proposal" (which was never made public) nor the "Specification" (which was the basis of the rules we are discussing now). We need to get a quick take on what those with an interest in this issue would like to see.
I also took a quick look through the existing FF/FC rules and I did not find a requirement like this in them.
Dave
Last edited by Dave Gomberg; 10.12.06 at 12:39 AM.
Thanks Dave,
You're right. It was never written. But we definitely discussed it in one of our many conference calls. We probably didn't add the the spec simply because it is not written in FC rules.
Regards,
Rob
Side pod width and height
When the committee adapted the drawing for the car dimensions, they inadvertantly adapted the precidents that are implied by the previous use of the drawing.
Specifically: the drawing shows the side and front crush structures. The minimum height of the side crush structure was specified in the rules. That is the minimum height of the crush structures. Note where the structure is on the drawing. If the rules specify a minimum height, such a rule is only meaninful if it is at a specific point and precident is that it is at the outer edge of the body. I don't think that any other formula car class allows the undertrays to extend beyond the outer edge of the sides pods.
Also think of the possible safety issue of wide undertrays when cars start wheeling each other.
If these details are not specified in the rules, then they certainly will be decided by some steward some where in SCCA and he might take the time to see what the precidents were or pull the decission from some very dark place. When these issues get to the stewards they and only they will decide what the rule means. All this chatter over this forum is meaningless when the stewards take on a problem. The stewards do not have to defer to the competition board. They are the ultimate rules arbitrators.
Because I have lived with every detail of these rules since I started building cars over 30 years ago, and because I have been in many protests over rules interpertation, I and others have begged you (the rules writers) to write rules that only required measuring instruments to determine whether a car is legal or not.
When I looked at the rules: body work so wide and so high, I interpert that to mean the outer edge of the car between the front and rear tires will be at least 20 cm high. If you want the rules to mean something else then spell it out. You may not like my interpertation but you best make sure that a steward is not in a position to agree with my interpertation.
Some people here may think Richard is over the top but this has been his argument all along.
No body on this forum appears to have asked the question of why were the FC cars not taking advantage of the underbody rules for SCCA club racing. The answer is that every one wanted their car eligable to run in the pro F2000 races and as long as no potential winner took advantage the lax club rules most of the cars stayed pro legal.
Now that F1000 has adopted some of the rules of existing classes, the history and precidents of those classes may prevail when there is a doubt about the interpertation of the rules.
I can guarentee you that this side pod issue will get to the protest stage because a competitive advantage will accrue to the car that has a maximum width undertray without being 20 cm tall at that width. We will also have to decide if the 20 cm is a minimum across the entire width or can I put a 20 cm tall end fence at the outer edge of the undertray. Will a rear wheel deflector or a radiator chimney pass as meeting the minimum body height requirements? For argument's sake how about a DB6 based car with a full width undertray and a wing mounted midway between the front and the rear wheels, half way up the body and an end fence that when combined with the undertray is 20 cm tall? Say the wing has a radiator inside like a Corsair fighter plane.
Last edited by S Lathrop; 10.12.06 at 9:07 PM.
diffuser staring point
OBTW, don't forget that different manufacturers make different sized tires, and that one could attach the diffuser to be perfectly legal on Avons and then find it to be well out of spec on a set of worn goodyears, so in practice one would have to start the diffuser break a bit aft of the leading edge of a typical tire.
Not true. Only the dimensions listed in the accompanying table are applicable.
In matters of the rules of competition the stewards DO have to defer to the CRB. Furthermore, the CRB can and does issue "on the spot" CE&O TB's any time the Stewards advise us that what is written is not what we intended. It happened as recently as yesterday.The stewards do not have to defer to the competition board. They are the ultimate rules arbitrators.
Then you would be wrong, Steve. The GCR specifically excludes the undertray from the definition of bodywork. If the undertray extends laterally beyond the sidepod then it is not counted in the 20 cm rule. That said, I like your idea of limiting how far beyond the bodywork the undertray may extend. I don't see this directly addressed in the GCR, tho the C/DSR section specifies that the bodywork must reach to at least a line connecting the centerlines of the front and rear tires. Adapting that, we could pick say, 6" (half the width of a converted FA's rear tire width). FWIW, there is an FC here with its ally undertray sticking at least 4" outside the sidepods (fugly, IMO); and Jim Downing's Ralt RT-41 CSR's sidepods fully exploit the half width rule (very attractively, IMO).When I looked at the rules: body work so wide and so high, I interpert that to mean the outer edge of the car between the front and rear tires will be at least 20 cm high.
Stan Clayton
Stohr Cars
Stan
If the side pod do not have to be 20 cm high at the outer limit to the body, what does the rule require? Why have the rule.
What happens when some one "wheels" a car with a wide undertray? If there is some amount of body work out to the edge of the undertray then there is a chance that the body will push the cars apart before the wheels become interlocked. This is one of the virtures of wide side pods.
Will accidents be more exciting when they start with one car getting a tire on top of some ones side pod at speed?
Most formula cars I am familiar with have the side pod even with the outer edge of the car at some point. In some rules it was common to specify a distance over which the outer surface fo the side pod had to extend.
It is one thing to be reluctant to specify driver safety standards, I think it is something else to allow construction practices that might worsen the safety of cars contacting each other. Drivers will touch other cars in competition. Without the body work defining the outer edge of a car between the tires, a driver can easily miss judge the position of a competitors car.
My money says that the Stohr defines the F1000 rules and what we see is legal. Just measure the Stohr and then write that into the rules. That is how it worked with Swift in FF and Lola before that.
That is an interesting thought- we never eevn considered the safety aspect of a large, uncovered sidepod floor. You are absolutely correct- the driver next to the "offending" car would not be able to see the floor extending beyond the bodywork as it would only be an inch off the ground. What happens when you contact the floor... loss of traction? Cut tire? Tire to tire contact? As someone who has had tire contact and launch I'd like to see this uncovered floor bit ruled out!
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Perhaps I am not understanding the thought process. If the driver doesn't see body work, that would mean he would feel it safe to tuck his tires in that space even though it is inside the width of the outer points of the tires? See what I am saying? The width of that floor is inside the max width of the tires as defined by the max. width requirement. Therefore the driver would be tucking his tires into the max width of the vehicle and putting both cars at risk if there was tire to tire contact. I am sure it happens, but I wouldn't think a driver would/should necessarily try that move and then blame the design of the other car as making it dangerous. Perhaps I am misunderstanding.
Ken
Ken
Floor/Sidepods
I don't think the issue is if a driver purposly puts a tire, between his opponents tire, but if he does there is nothing to impead the progress of the tire inwards and resulting an a larger tire to tire contact patch. I'd personally like to see it kept simple and safe... Decide how wide you want the floor and force the sidepod to be as wide and have a min certain height for a certain percentage (Or Min) of the distance between the real wheels. When Driving, I'd like to be able to see the full car, and not worry that the car ends under the line of sight offered by my mirrors. In addition. I waould guess, forced sidepods also offer increased side crush protection.
Last edited by racer27; 10.13.06 at 12:15 PM.
AMBROSE BULDO - Abuldo at AOL.com
CURRENT: Mid Life Crisis Racing Chump/Lemons Sometime Driver (Dodge Neon)
CURRENT: iKart Evo Rotax 125 Kart
GONE: CITATION 87/93 FC - Loved that car
GONE: VD RF-85FF , 1981 FIAT Spider Turbo
Floor vs. Sidepod
So if the floor is specifically excluded as bodywork....then is there a maximum floor width besides what is defined as the maximum car width? In theory, wouldn't it be possible to build a max car width floor?
By the way, our car does use a small protrusion of the floor in front of the sidepod and along the side....we'll change it if we have to I guess.
I agree with Stan that maybe it would be a good idea to look at defining the maximum width that the floor could extend past the widest part of the sidepod.
Matt Conrad
Phoenix Race Cars, Inc.
Last edited by Matt Conrad; 10.13.06 at 12:40 PM.
Again, I am probably overlooking something, but in the midst of all this, I don't hear any complaints about the fact that there is no minimum sidepod width.
Having no sidepods is just fine, but if we have a sidepod that comes out most of the way, with 6" of undertray lip, then that's unsafe? Say what?
Cheers,
Rennie
Undertray vs. side pod width
Renne: Try rephrasing your question.
I think that someone was questioning what would happen when one car "wheeled" another car. Have you never seen the marks on a side pod left by another cars tires?
No other formula car class, that I am aware of, allows the undertray to extend beyond the widest point of the side pod.
The question was what would happen to the car doing the touching. Would the tire be cut down by the edge of the undertray or would the toucher ride up on top of the undertray? Currently little happens. With wider side pods the cars might be safer if the undertray did not extend beyond the widest point of the side pod.
As Stan has correctly pointed out, the undertray is only limited by the maximum over width of the car. The undertray can extend to the outside edge of the tires or beyond.
I will bet that there is a lot of free down froce available by extending the undertray to the full width of the rear tire and forward about 6 to 12 inches.
Steve,
I'm not questioning the effects of "wheeling" another car. I used to drive Sprint cars on dirt, believe me I'm intimately familiar with the effects of interlocking wheels. What I am questioning, however, is why all the hubbub about the safety of undertrays extending beyond sidepods, when there is no minimum sidepod width or crush specification. In practice, an unreinforced undertray is going to snap off like a Ruffles potato chip when a tyre runs up on it. Reinforced undertrays, well... your guess is as good as mine, and will vary by the design.
See, the problem with the current discussion is that it's all a staw man. Even assuming that the undertray is prohibited from extending past the plan view profile of the sidepods (a good idea, in my opinion), there is nothing to prevent an enterprising competitor from incorporating a set of "blanking" shrouds for the purpose of legality. Hell, right now you can just put a single 20cm high strip of sheet aluminum at the outboard edge of the undertray and you're legal for sidepod height - and if you keep the undertray width to the sidepod max width, you wouldn't even be breaking any rules about extending past the plan view profile of the sidepods. Put a roof on that, and you've even maintained a constant 20cm height for the full width of the sidepod.
A tyre ramming into the side of that kind of sidepod is going to crumple it like a tissue, and you're left with the same situation - rotating tyre on top of the undertray. Bottom line - we haven't got a standard for how crush resistant a sidepod has to be in order to create the kind of safety we're looking for.
Cheers,
Rennie
I saw a '95 Citation at the runoffs today. Think it was yellow and red, finished 5th in FC I believe. The diffuser on it stuck out wider than it's sidepods. Think it's been like that since the '94 runoffs.
I imagine that's the same car I recalled seeing the other day, and mentioned in an earlier post. If I were guessing, I'd say he extended the floorpan to the maximum 95cm width.
Actually, the FA FF and FC rules do not address the issue as far as I saw, tho the F500 rules do. I have to dash to the track now, but I encourage interested readers to take a look at the F500 bodywork rules. We may be able to profitably borrow some of their language.
BTW, Steve, I am a "public person" and you can insult me all you like, but your gratuitous slap to the face of the initiators of the F-1000 concept is over the top. Bill Maisey first proposed the class in Dec 2004, and the first set of rules was drafted and published in January 2005. Furthermore, the Stohr design was not started until 9 weeks ago, and not seen by anyone outside their little enclave in Portland until late last week (and not by myself until last Sunday). To say that we simply measured their car and defined the rules is pure, unadulterated B.S., and I think you owe them an apology.
Stan
Stan Clayton
Stohr Cars
Froggy: You are right. However the FFs are not that way. The extension is about 1 inch. It came about because I was trying to minimize the frontal area of the car as much as possible. Were I to do it again I would widden the side pod to the maximum to improve the air flow through the radiators. The first of the five cars I build in '94 was Oseth's Ford and all the other cars were done the same. I haven't gotten around to fixing that problem.
5th place ain't bad for a 64 year old man in a 12 year old car, starting from the rear of the pack. That pair still and will for ever hold the Mid Ohio FC runoffs track record.
The question before this forum is whether this is a good practice. Should we stop the practice before it starts or are the rules set now that Lee Stohr has presented his car?
Rennie: My question is still what does the 20 cm rule mean? Or better yet why is the rule even there? The rule is not sufficiently defined to mean any thing that I can see. But in a protest before some steward if might have a meaning that nobody intended. Your sprint car had nerf bars for protection. You of all people should see the problem here.
Floor vs. Sidepod
Just because Lee has presented his car doesn't mean anything as far as the rules go. The car he has built is only his interpretation of the rules and it was constructed prior to the rules being fully set. I personally don't see anything in the rules that says it is illegal, but that does not mean that the rules can't be clarified to address the intent of those that wrote them.Should we stop the practice before it starts or are the rules set now that Lee Stohr has presented his car?
I have spoken to members of the original rules committee and they said the INTENT of this rule was to allow cars with wider sidepods, but to set a minimum sidepod height so that all cars would have to run them (and have the added drag associated with them). I also believe the intent of the rulemakers was to prohibit the use of floors outside of the sidepod footprint....but it wasn't specifically stated. I know some of you are following this....am I wrong?
Again, our F1000 design also has the floor sticking out past the sidepod profile so I believe this issue probably needs to be clarified before too long and anybody that feels strongly one way or another should send a letter to the CRB. Sorry for the crude sketch, but here's another example of a design we looked at....does this meet the rules?
Matt Conrad
Phoenix Race Cars,Inc.
Enough is Enough
I wasn't ever going to bother commenting ever again on what is going on here, but after staying away for a week, coming back, and seeing this sort of crap, as well as the current state of the rules, well, enough is enough.
Stan: You better get used to getting upbraided publicly if you continue to show such a total lack of capability in reading comprehension.
There is a big difference between Steve's suggestion that you now just go measure what Stohr built according to what he thought the rules would be and then setting the rules according to those measurements, and accusing someone of having set the rules just so that Stohr could build what he did - that accusation is flat out NOT what was written.
If you cannot comprehend such a simple suggestion, how can anyone ever expect you to correctly comprehend the ramifications of technical specifications?
If this is truely your level of technical and reading competancy, please resign NOW from the CRB before you do any more harm.
Please guys... can't we kee this civil? I know we ALL want what is best for the club and the class even if we see what is best in differing ways....
The bickering, etc is just counter-productive.
Matt, I think your design would pass what we had discussed. Does it push the envelope? A bit, but it still keeps tires off undertrays and that is the most important bit. The only problem I see is your design progressing to an even more narrow wide part (?), or even a winglet as Steve suggested. How to write that into the rules I'll leave to the experts. Any suggestions Richard?
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Side Pods
Matt's got the idea.
With the bodies being wider, the chances of contact with the side of a car is more likely.
You might want to spec a minimum surface area at the outer edge say 10 cm. Some specification that assures a benign surface when contacted by a tire.
Steve,
To determine what the 20cm rule means, we first have to define what a sidepod is, and we have to establish whether the rule requires a finite point measurement, or a planar measurement.
If we define the sidepod as the bodywork which sits atop and is separate from the undertray, then logically the 20cm rule does not apply to the undertray. Hence, any sections of the undertray that protrude beyond the plan view boundaries of the sidepod are not required to be 20cm tall, because they do not fall under the purview of the sidepod height minimum.
If we define the sidepod to include the undertray, then the 20cm rule does, in fact apply to the undertray. The only determination left to make then is the type of measurement, i.e., planar or finite point.
If it's a planar measurement, then everybody is in trouble. I've seen plenty of FC sidepods that taper vertically in the rear to blend with the undertray. I think every FC in existence has sidepods which taper laterally to blend with the sides of the body, leaving square feet of undertray exposed and below a 20cm plane.
I would submit that the generally accepted interpretation is that sidepods are separate from the undertray for measurement purposes, and that it is a finite point measurement. If that were not the case, then most every car would be illegal. Now, the fact that most FC sidepod implementations have slab sides and roofs means that it's either a purposeful interpretation on the part of the designer that these sort of features are required, or it displays a complete lack of imagination on the part of the designer, or there was a business decision involved such as cost of construction, etc.
Steve, you haven't come right out and said that the Stohr is illegal according to the rules, but the tone of your posts (i.e., measure the Stohr and re-set the rules) indicates that you do feel that it's illegal. Can you outline the specifics of why you feel that to be the case?
Cheers,
Rennie
Stan
Lets back the rhetoric down. I did not intend to demean the work and effort of the rules committee.
Many people, on and off that committee, have put a lot of work and effort into this project so far. I thinK a good set of rules for F1000 is worth the effort.
What I really want to see is a set of rules that are tightly crafted so the limits are well defined; rules that are easily understood by builders, competitors and officials alike; and a set of rules that assure safe, fun, and exciting cars.
I have been burned many times over the last 30 years because this part of SCCA racing was not done well. I would like to be a player in this class as a vendor of parts, services and maybe even cars. This is the passion I am bringing to this discussion.
If after a quick glance at a poor quality picture of Lee's car I have questions about the rules and the car in the picture, then something is wrong with the rules. If it takes a more knowledgeable person than myself to understand the rules then maybe there is a problem.
Accept what I say as being in good faith and lets get on with making this the great class it can be.
Rennie: See what I mean about tightly crafted, easy to understand rules? When I built DaveW's car 12 years ago, I always thought that the undertray was limited by the body work rules. It was under the body work. Further more I would assume that top surface of the undertray was considered to be body work. When I see a rule specifying a minimum height of the side pod, I assume it was to be at the outer edge of the body. Notice that even members of the committee had to rethink this question.
Requiring that the minimum height of the side pod be at the outer edge of the body may be an excellent device to equalize the performance of a converted FC and the Stohr.
Last edited by S Lathrop; 10.14.06 at 3:52 PM.
IMHO, below should be legal... clearly the floorpan extends beyond the sidepod but only along the length of the car, not extending beyond the width of the sidepod.
Sean O'Connell
1996 RF96 FC
1996 RF96 FB
2004 Mygale SJ04 Zetec
Steve,
The rules, in my opinion, are intended to establish the boundaries within which the designer is permitted to play. While I wholeheartedly agree with you that these boundaries should be easy to understand and verify, I completely disagree that they should be tightly specified. I have no desire to see this morph into a semi-spec class whereby a competitor can construct the same basic car as everybody else just by reading off the specs in the rules. Your opinions may vary, but that's mine.
For what it's worth, requiring the minimum height of the side pod to be at the outer edge of the body won't really accomplish anything. Why, you ask? Take a length of aluminum strap, rivet it laterally to the top of Lee's sidepod, and cut it off at the maximum width. Voila, you now have your sidepod height at the outer edge of the body, all nice and legal-like.
Honestly, this whole "the sidepod must be 20cm tall" issue is about as enforceable as "no venturi sections in the underbody". What is a sidepod anyway? Or is this one of those "we'll know it when we see it" kind of things? I'm surprise and shocked, frankly, that Richard hasn't taken up this issue, since it's a glaring one that's been staring everybody in the face for 40+ years. I don't see this so much as an issue of technical competency, but rather one of a fresh perspective on rules that established players take for granted.
For instance, when I read the sidepod minimum height rule, I do not interpret that to mean that the undertray is part of the sidepod height measurement. I also do not interpret that to mean that every part of the top surface (as viewed from above) must be at or above 20cm. When you go to a theme park, and the ride says your kid must be a minimum of this height to ride, does that mean that if your kids shoulders are below this height that he can't ride? For that matter, the rules do not locate a reference point from which the measurement is to be taken.
Anyway, here is my recommendation: define a volume for the sidepod which must be covered when viewed from above and from the sides. Of course, the catch is that you will likely need to make this volume small enough to fit within the envelope of existing FC sidepod designs...
Sean,
So what you're saying is that the undertray should not be wider than the widest point of the sidepod, as opposed to not being permitted to extend past the plan view silhouette of the sidepod. What about the case I outlined above where you install a piece of strap aluminum whose sole purpose is to extend the width of the sidepods?
Cheers,
Rennie
Sean:
I really see no good way out of this mess, considering the conflicting desires posted so far. This is going to be a looooong post, so bear with me!
The first thing I thought when I saw the bodywork width rule was that the width of the undertray wasn't included, therefore allowing narrow sidepod skins (subject to the "bodywork" width and height rules) but with thin undertrays allowed out to the maximum overall width (NOT subject to the bodywork width and height rules - the bodywork rules specificly state "bodywork" and do not include the undertray , as it is now not considered to be "bodywork" as per the Glossary definition). This was so obvious as to be rediculous.
As stated many times before " intent" is BS - if it isn't written in the GCR, it really doesn't exist as a rule. "Intent" may serve as a good rules debate tactic sometimes, but really has no legal bearing.
( As an aside, the inclusion of the Glossary as an "official" reference is reletively new - prior to a few years ago, it actually COULD NOT be used in determining legality! Both Steve and I are guilty of having missed this change until recently, and I WILL thank Stan for getting me to notice this when at some post a few months ago he pointed out the glossary definition of "bodywork".)
However, the definitions given of the three items that can have bearing on the rule you want all pose differing problems.
For instance, the floorpan is described as the panel that "separates the interior from the undersides and acts as support for the seat(s)". To most of us, this would be interpreted as being the traditional alu skin bonded to the bottom of the frame rails.
The Undertray(Belly Pan) is described as an attachment to the undersides to smooth airflow. Traditionally, this has meant a separate panel, different in function of that of the floorpan, and includes the bottom portion of the sidepod.
The Body is described as being "all parts licked by the airstream and above the floorpan/bellypan."
So, the first problem becomes just what you want to consider the top skin of an undertray and/or floorpan, IF that top skin is "above the floorpan/bellypan"?
If BOTH a floor pan and an undertray are utilised, then the arguement would be that the top skin of the undertray IF it is above the floorpan is automatically considered bodywork, and subject to the bodywork rules - the rules don't state that the offending part has to be above both the floorpan and undertray, just that it be above either of them.
But, to confuse the issue further, if the "undertray" is in fact also the "floorpan", and if the undertray has bonded to its top skin ( AND that top skin is no higher than the portion that is under the frame rails) some vertical panels that form part of the sidepod shaping, is that going to be considered "undertray" or "bodywork"? After all, how can it be considered to be "above" the undertray, if indeed it is an integral part of the undertray? How can something be above itself?
I would venture that what we want is this at a minimum: Anything that is above the floorpan and/or undertray, primarily horizontal, top skin, should be considered to be bodywork and subject to the bodywork rules, and should be declared as such in the rules package. After all, everybody here seems to want the rules to be such that "if it doesn't say you can't, then you can", if the previous debate over the stressed floorpan is any valid indication!
PS : Which side of the floorpan are we referencing to: the top surface or the bottom surface?
The next problem to confuse you is this:
If only an "undertray" is utilised, ( and actually even if a "floorpan" is utilised, come to think of it) AND it steps down at the outer edges ( but not below the reference plane) what width rule is that area subject to if the undertray below the floorpan surface is not considered to be "bodywork"?
I could add more scenarios, but I think you should be getting my drift. The only way out of this problem is to declare the undertray to either be bodywork, and therefore subject to all of those rules, or to state a maximum undertray width in addition to the bodywork width rules.
(As a real off-to-the-side aside, the FF/FC rules now have this same problem - the undertray can now legally go out to the maximum allowed car width ( and in FC, it is even worse, since they declared that "measurements indicated at the rear are for the rear", etc - there are NO references to the max width at the center of the car! Also, the fact that there is no reference to the maximum allowed front width means that I can legally have a ten foot wide front track if I wish!) This sort of idiocy in rules writing is what is getting me totally pissed off - you guys deserve better.)
OK. Back to the subject at hand.
So let's say that we all agree to limit the max width of the undertray and/or floorpan to the same as the max bodywork. What do you want to do now about limiting how far the undertray/floorpan can extend past the bodywork?
Quite frankly, I don't think there is a darned thing you can do that won't make one of the existing designs illegal. Possibly, about all you can do is to try to minimise the consequences - ie - the tire-cutting hazards that some are concerned with - by stating that, for an area starting at xxx inches from the trailing edge of the front tire to xxx inches from the leading edge of the rear tires, the outer edge of the undertray and bodywork directly above it shall either be flush ( a "shadow" rule as it used to be called), or, if not flush, the undertray cannot stick out more than xxx inches from the vertical wall formed by the bodywork above that point.
The problem with that, however, is that most existing cars will be illegal at some point along their sides between the tire edges.
So, what to do?
My suggestion: FORGET IT! You ain't gonna come up with anything that won't make most cars illegal as they currently sit, and FORCING a major body reshaping on converted cars goes directly against what this class is supposedly all about, and heaven forbid that the Gloria and Speads could be forced to change their designs to fit our rules.
As far as what sort of hazard an exposed undertray edge poses to a competitors tire : I think Rennie is mostly correct that, since these parts are not allowed to be made from carbon fibre ( which loves to cut stuff!), but primarily out of 'glass and kevlar, they will fold without much resistance if contacted by a tire.
However, since stronger and stiffer materials such as steel or alu strips bonded in for edge integrity cannot be ruled out, even that assumption ( the easy folding) cannot be applied as actual fact - in fact, if the undertray goes out to full width and is shaped correctly, the loads on it will require support stays or wires, and the addition of some sort of cohesive material reinforcement at the outboard attachment points to keep the anchors from pulling through.
So, if the concern is that a sharp edge to the undertray can pose an unacceptable hazard, then eliminating the use of sharp edges would seem logical.
But what does that mean as concerns any existing cars? I confess that I don't have a definitive answer, but I think that it would probably be safe to say that a LOT of cars have sharp edges somewhere along their sides. Again, are we going to force changes that may or may not really be necessary for FC width sidepods? Also, what's going to be the definition of a "sharp edge"?
And if you think you are going to just simply require that the minimum height of the outer edge of the sidepod, including the undertray, is to be 20 cm tall, then all I need to do to satisfy that requirement is to attach a thin fence along the edge.
Short answer after a long post: At the moment I cann't think of any way to satisfy all the concerns without somebody being forced to make major changes. So forget even trying and live with the consequences - you guys wanted the wide bodywork allowance, so don't start bitching now that you finally are understanding some of the problem associated with it!
Last edited by R. Pare; 10.14.06 at 8:32 PM.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote