diffuser and wing clarifications in January Fastrack

[Mike Devins]

and also in the january fastrack on page 20 (underlined portion is struck - formatting would not copy


1. Change section 9.1.1.H.3.E, p. 243, to read as follows: A diffuser is permitted behind the front of the rear tires. The maximum width of the diffuser is 95cm[The diffuser may be divided internally into multiple sections. The radius of transitions between the diffuser sides and adjacent horizontal structures may be up to 25mm. The width of the diffuser, as measured between its sides and above any radiused transitions, may not exceed 95cm in any lateral section. Strakes within the diffuser are allowed.

2. Clarify line “K” of the F1000 Dimensions Table, p. 245, to read as follows:
K. Maximum front wing width (includes endplates)………


I know that per my conversations with Dave Gomberg the mearsurement is meant to be taken inside of the diffuser although I can still see how this could be interpreted either way. Maybe the word between is the hook.

[martyb]

and also in the january fastrack on page 20

2. Clarify line “K” of the F1000 Dimensions Table, p. 245, to read as follows:
K. Maximum front wing width (includes endplates)………

I wonder how wide our front Stohr F1000 wing is, as I would assume that those cute little winglets at the bottom of the endplate would have to be included in that dimension ......

Marty

[Mike Devins]

According to Phil Creighton it includes "all of the wizzy bits" except bolt heads.

[Rennie Clayton]

1. Change section 9.1.1.H.3.E, p. 243, to read as follows: A diffuser is permitted behind the front of the rear tires. The maximum width of the diffuser is 95cm[The diffuser may be divided internally into multiple sections. The radius of transitions between the diffuser sides and adjacent horizontal structures may be up to 25mm. The width of the diffuser, as measured between its sides and above any radiused transitions, may not exceed 95cm in any lateral section. Strakes within the diffuser are allowed.

WTF does this accomplish?

[Mike Devins]

Rennie,

Since i was the one who stirred this pot I will give you the history.

In FC there is no rule as to how wide the diffuser can be because it is controlled by the max width rule. When the FB rules were drafted they simply added the Max 95cm rule for the diffuser. The issue was the definition of a diffuser since the GCR does not include one in the Glossary, I had a customer request that I build him a diffuser to max allowed by the rules so I needed to be able to understand where the 95cm would be measured.

So I started making calls and had as many different answers as I made calls. Some thought that the 95 included the horizontal flanges at the bottom of the diffuser which would be the same as in FC. Some thought that the outside of the vertical walls others the inside.

I called Jeremy at the SCCA and his answer to me was "that is a good question".

So what is accomplished, I hope, is that I can now build a diffuser that is 95cm at the widest point measured at the inside of the diffuser and not have to have not have to worry that my customer would be protested.

The horizontal flanges that are outside of the diffuser vent will be controlled by the maxfloor width rule for the floor.

Hope that helps and have a Merry Christmas.

[Mike Devins]

BTW the first diffuser will be done sometime next week.

[Rennie Clayton]

Rennie,

Since i was the one who stirred this pot I will give you the history.

In FC there is no rule as to how wide the diffuser can be because it is controlled by the max width rule. When the FB rules were drafted they simply added the Max 95cm rule for the diffuser. The issue was the definition of a diffuser since the GCR does not include one in the Glossary, I had a customer request that I build him a diffuser to max allowed by the rules so I needed to be able to understand where the 95cm would be measured.

So I started making calls and had as many different answers as I made calls. Some thought that the 95 included the horizontal flanges at the bottom of the diffuser which would be the same as in FC. Some thought that the outside of the vertical walls others the inside.

I called Jeremy at the SCCA and his answer to me was "that is a good question".

So what is accomplished, I hope, is that I can now build a diffuser that is 95cm at the widest point measured at the inside of the diffuser and not have to have not have to worry that my customer would be protested.

The horizontal flanges that are outside of the diffuser vent will be controlled by the maxfloor width rule for the floor.

Hope that helps and have a Merry Christmas.

Well, at least now we know it was a well-intentioned individual seeking clarification of the rules. Unfortunately, this "clarification" is about a useful as tits on a boar since it can't really be objectively verified against the presumed intent in any way, shape or form.

So since each section can be 95cm wide, as long as you make it in multiple sections you can have just about whatever the hell you want via this rule. Sweeeeeeet.


Cheers,
Rennie

[Jnovak]

1. Change section 9.1.1.H.3.E, p. 243, to read as follows: A diffuser is permitted behind the front of the rear tires. The maximum width of the diffuser is 95cm[The diffuser may be divided internally into multiple sections. The radius of transitions between the diffuser sides and adjacent horizontal structures may be up to 25mm. The width of the diffuser, as measured between its sides and above any radiused transitions, may not exceed 95cm in any lateral section. Strakes within the diffuser are allowed.

I think the wording is actually pretty good.

1. While it does not clearly say "inside" or "total" dimension, it is very clear that it says "between" which in my opinion means inside. However a clarification to add the word "inside" would not hurt.

2. It also says that the width of the difusser may not exceed 95CM between the sides. This clearly means ANY sides of the difusser. So you simply cannot have say 3 sections that are each 40CM wide for a total of 120CM width & then say that the difusser is only 40CM wide unless you wanted to try to say that the outer sections were not difussers. So the distance between ANY SIDES is what counts & that cannot be greater than 95CM.

Thanks ... Jay Novak

[martyb]

It appears that the rules clarification has outlawed the factory front wing that every Stohr F1000 was delivered with. Don has already written the CRB complaining about this; have the rest of the Stohr owners done so yet?

Marty

[Jeff Read]

Marty ,Time to get out the Sawzall

[R. Pare]

The front wing width in every class that I know of has always included the end plates, but not the bolt heads. Unfortunately, that has never been specificly stated in the rules, even though we've made many attempts in the past to get it rectified. Seems that the ramifications of not getting that clarification has now come home to roost!

[RussMcB]

Haven't wing width limitations always included end plates?

Oops. I see Richard beat me to it.

It's a good clarification. Otherwise people could go nuts and effectively create downforce with pieces wider than the legal limit.

[martyb]

Haven't wing width limitations always included end plates?

Oops. I see Richard beat me to it.

It's a good clarification. Otherwise people could go nuts and effectively create downforce with pieces wider than the legal limit.

I have no objection to the clarification, but it is a shame that it outlawed the car that is the highest percentage participant in this class. I know that we don't really want to have to buy a new wing to be legal again!

Marty

[RussMcB]

I know that we don't really want to have to buy a new wing to be legal again!

You can't just replace the end plates? Or trim that bottom part?

If you have to replace the whole wing, I can understand how you'd be unhappy with SCCA (and Stohr designers).

[WFelch]

It is the opinion of Stohr Cars that the rules clarification as posted in the Fast Track is actually a rule change. The 2007 GCR does not include wing end plates in the dimensional rule for the front wing. The standard front wing delivered with every production car with out end plates is 133.5cm in width, and is therefore legal even after the clarification. In the short term, anyone worried about being protested can run without end plates, or cut the end plates off short. For the future, we have written a letter to the SCCA regarding this matter.

For our customers interested in flat end plates we have them available.
We are sorry for any inconvenience.

Wayne Felch
Stohr Cars

[R. Pare]

As the dimension for wing width has "been known" for 25 years or so to mean that it includes the end plates, i think you will find this to be declared a "rule clarification", rather than a rule change.

Nicy try, though.

[Mike Devins]

I do not disagree that the assumption has always been that the endplates and "wizzy bits" are included but in the FC rules it is specifically stated "including endplates" so why was it not stated that way for FC since the FB rules were basically a "copy and modify" of the FC rules.

[Dave Gomberg]

I do not disagree that the assumption has always been that the endplates and "wizzy bits" are included but in the FC rules it is specifically stated "including endplates" so why was it not stated that way for FC since the FB rules were basically a "copy and modify" of the FC rules.

Mike:

The FB and FC tables were different in this regard from the beginning - and still are. The corresponding FC table entry is not for the width of the front wing, but of the nose, where "nose" is only defined by the drawing below. In the drawing, dimension K actually refers to the front wing, so if anything, the FC table entry is quite flawed. I guess we should address it as well. At this point, it is hard to know how these weirdnesses came to be.

Dave

[Mike Devins]

Sorry Dave that is what for working from memory instead re-reading the rules. The reference to "includes endplates" was actually in the FB rules for the rear "aerofoil"

[S Lathrop]

Mike and Dave:

Is not the drawing in the FC and FB rules the same? The drawing does show end plates. If you look closely, I think the dimension lines are even with the outer edges of the wings and the end plates. At least it appears that way to me.

It seems to me that there should never have been a question about the end plates.

Or it may be that old age has reduced my ability to look at rules imaginatively.

[Mike Devins]

Steve,

The situation is that at least one manufacturer read the rules, made an honest mistake and did not include the endplates in the dimension. i know from the conversations I had relating to the diffuser portion of the clarification that the club does not intend use these clarifications to cost its members money. I hope for Wayne and his customers sake that they can find some middle ground here as well.

[S Lathrop]

I have spent more time reading the rules and looking at the diagram.

You can reasonably argue that the outside of the front endplates are part of the body work ahead of the front tires. In that case there is no limit on the width. I don't buy that argument because the endplates are an integral part of the functioning of the front wing and therefore are part of the front wing. But it is reasonable.

Even with the "clarification" there is no limit on the body work ahead of the front tires. If I fashioned fairings forward of the front tires similar to what sprots racing cars have for front fenders but kept the height below the top of the front rim (F500 type nose) I would be legal. I don't see anything wrong with supporting this structure by the front wing.

It seems to me that Stohr only got the shape wrong.

I thing the "clarification" still does not have it right. It should be that nothing forward of the front tires may exceed 135 cm

As pointed out, the Stohrs only have to run thinner end plates as the wing is well within the limits. There are more cars that meet the rules than don't. But SCCA has rewritten rules to accomodate Lola and Swift so why not Stohr?

[Mike Devins]

Stohr is not the only one who interpereted the wing rule that way. I know of at least 10 other wings that will need to be altered or they can not run end plates.

It is in the CRB's hands now so send in your comments soon.

[RussMcB]

Please excuse my ignorance, but what really is involved in making the Stohr cars comply? Is it more than a 10 minute, inexpensive task?

On edit: Never mind. I guess it's not as simple as bolting on different end plates or modifying them.

[S Lathrop]

Anyone who is building a F1000 and is coming from a SCCA winged formula car back ground (FC, FSV, FA) knows what the rules have been. Those running spec formula cars don't have the worry because the rules are written to fit the car. Someone from a different back ground might stumble on the rules interpertation.

Those who wrote the rules were not explicit enough to avoid this problem.

I am surprised that anyone got caught out on this rule because of all the histroy involved. But if you focus is only what is written and illustrated in FB section of the GCR you might have made a mistake.

My FB front wings can be trimmed to fit what ever the rules end up. Personally I prefer that the FB and FC rules are the same.

[Jnovak]

Based on Wayne Felch's response I suspect that the Stohrs will just have to replace the end plate or trim them.

Thanks ... Jay

[Billy Wight]

Anyone who is building a F1000 and is coming from a SCCA winged formula car back ground (FC, FSV, FA) knows what the rules have been.

I am surprised that anyone got caught out on this rule because of all the histroy involved. But if you focus is only what is written and illustrated in FB section of the GCR you might have made a mistake.

It shouldn't matter what the rules have been for other classes, it should only matter what the rules are for the FB class. Isn't the racecar engineer's job to exploit the rules as much as possible in order to get a competitive advantage??? I understand the points made in regards to what other class rules are and what the intent of the rule may have been, but if the FB rules didn't specifically state that the width included the endplates then I would be making my wings at full width then bolting on the endplates on.

[S Lathrop]

It shouldn't matter what the rules have been for other classes, it should only matter what the rules are for the FB class. Isn't the racecar engineer's job to exploit the rules as much as possible in order to get a competitive advantage???

It sure is easy to get caught out. When the picture is the same and most of the words are the same, I wrongly guessed that the interpertation would be the same. Have I missed something here? Didn't the clarification say that the old interpertation was correct?

I thought I gave you an interpertation that would allow tire fairings to any width. Those fairings just can't be "end plates". There is no minimum width for the body work ahead of the front tires.

[Matt Conrad]

We used the existing FC rule as our guide when we evaluated wing configurations for the FB car. It was always our understanding that the front and rear wing dimensions for FB were going to be the same as FC and included the endplates.....even though for some reason it was not stated in the initial rules regarding the front wing.

The way it is worded in the FC rules is that it refers to the "Nose" and the drawing shows the nose width as the entire front wing assembly. I'm pretty sure the rule writers intended the rules to be that the entire front wing "assembly" needed to be under 135cm and the clarification seems to reflect that.

Matt Conrad
Phoenix Race Works, LLC

[Billy Wight]

It sure is easy to get caught out. When the picture is the same and most of the words are the same, I wrongly guessed that the interpertation would be the same. Have I missed something here? Didn't the clarification say that the old interpertation was correct?

I was just pointing out that since it wasn't explicitly stated that the wing dimension included endplates, it was reasonable to make the wing the full width and bolt on the endplates. Now that there is a clarification (which really should have been there in the first place) it makes sense that this would not be allowed. It's just unfortunate that a lot of cars have to change their endplates now to be legal.

[S Lathrop]

Just for discussion, how wide can you make a "sprots car" nose?

As I read the rules, there is no limit on the width ahead of the front tires.

Billy;

Read the first paragraph of the rules for F1000. That is the gotcha clause.

[iamuwere]

interestingly, there is no definition of a sports nose in the rule book and Jeremy could only give me a definition of "you know what a sports car nose looks like"

[S Lathrop]

What Jeremy should have said was "it is not a wing". The early March and Ralt Formula Atlantica and FSV used 'sprots car noses".

[Jeff Read]

Here is a pic of a Sports car nose on a March 76B. Excuse the quality of the pic as I took this when I was 6 or 7 years old..