Alternate Class for Sevens

[slngsht]

 

Interesting discussion. What this photo does not show is the 330 pound steel plate that is bolted to the bottom of this car to bring the weight up to 1775 pounds. That's 350 pounds over D mod minimum weight.

 

Also, the transmission was broken so the whole event was run in high gear, starts and all. The protested car was second in D Mod, and second in E mod, with no changes except driver.

 

This car has been in develoment for 35 years.

 

One more thing. The motor is stock except for the after market cams.

 

Del Long

 

 

 

Del, welcome to usa7s (although this is an odd thread for a welcome http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif )

 

 

 

Since the protestor, protestee, contestant, and bystanders are all here now http://www.usa7s.com/aspnetforum/images/emoticons/grouphug.gif , let's focus on the task at hand.

 

 

 

I'd love to hear your take on what to do with "stock" Sevens for a competitive place to run.

[locostv8]

Sorry bout the size but at a reasonable size the dimensions couldn't be read.

 

 

 

...

 

However I disagree with your logic that all sevens ar mods of a Ford.

 

 

 

To follow that logic then all 911s would be mods of the first Porsche. Not distinct modles....

 

Michael D.

 

 

 

Actualy the original was more like the Meyers Manx to the VW.

 

 

 

   I could be wrong but after reading this thread, and the proposed "new rules" it seems to me that some of you are looking to get Locost or home-built cars out of your class.

 

 

 

Am I mistaken?

 

 

 

....It can not be said of the locost cars because there is no production standard or list of required components.....

 

Michael D.

 

 

 

Branded Sevens are defined by the manufacturer and are therefor included as Sevens. The only Sevens on the road that are not clearly defined are Locosts and other one ofs that people put together.

 

 

 

It would seem to me that a simple spec would be to take the specs from a Lotus & or a Caterham Seven and make them the minimal dimensions. I believe they are the same.

 

 

 

Lrger and heavier would be acceptable.

 

 

 

I agree with Chet. As long as the Locost fits within the specs IE is not smaller than the Lotus Series 1 then it should be every bit as elegable to run as a 7.

 

http://www.usa7s.com/forum/uploads/20061102_001014_sevencut.gif

 

http://www.usa7s.com/forum/uploads/20061102_001052_sevenm.jpglocostv82006-11-02 00:13:49

[slngsht]

Sorry about the forum software cutting off the graphic... To view the full graphic, right click on the image, click here: >http://www.usa7s.com/forum/uploads/20061102_001052_sevenm.jpg

 

 

[slngsht]

Chetco and LocostV8,

 

I have limited knowledge of Locosts...

 

Can you guys give a brief description of:

 

1. What a "book chassis" is?

 

2. The common variations of a book chassis? I have seen references to the +4, or the 442.

 

3. Who are the main vendors who make standard book chassis? I think Coveland does. Others? Do they really follow the book?

 

 

 

I think there has to be room here to separate locosts that are built to some specification, from locost that are really engineered on their own.

[Locostdude]

One of the most complete online sites available for Locost chassis information is

 

The McSorley Home page has 3d drawings and much more.

 

***************************************************

 

As to defining a "Standard" seven for a new autocross class, I don't know for sure.

 

I don't know what the goal is.

 

Do you want a class for un-modified factory built Caterham 7's? Or do you want class for limited modified seven like cars?

 

The SCCA Modified Advisory Committee (MAC) went through a long laborious process trying to come up with a set of rules that would bring parity to different types of cars, from unibody, to body on frame, and include the Lotus 7 type cars.

 

At least your task is limited to only Lotus 7, tube frame, and body type cars.

 

The MAC eventually defined what were competition producing items: Minimum weight, low center of gravity, wheel base, track, and horse power (engine size) were some of the items. The Lotus 7 was one of the obvious leaders in every one of those categories, so many of the minimum dimensions chosen for D/E mod were based on the Lotus 7. The minimum allowed floor pan dimensions are those of the Lotus 7. The floor pan minimums limit the length and width of the smallest car you can build (for D/E Mod).

 

Do you want to allow "in excess" cars?

 

Do you want weight breaks for different engine displacements?

 

Do you want to regonize the different performance potentials of OHV, OHC, DOHC engines?

 

What tires will be allowed, race, street, high perfromance DOT R tires?

 

If this is an SCCA class all cars will need to meet the minimum safety requirements of section 3.3 of the SCCA rule book. (roll bars, seat belts, etc)

 

Good luck, the SCCA has been working this problem (the Lotus 7) for ever. It all started when the Lotus 7 was approved as a "Production" car. Probably a bad idea.

 

 

 

Del Long

[locostv8]

http://mcsorley.net/locost/#Building%20a%20Sevenesque%20Sports%20Car

 

http://locost7.info/mirror/mirror.php

 

 

 

Actualy the "BOOK" chassis is closer to the original than the chassis produced by some of the vendors, Robinhood in particular. Again the "7" is by it's origins a Hill climb Special built on the components taken from production cars(race car built to racecar specifications of 50 years ago, MOD) with most being built from kits as one offs.

 

 

 

What the Dude said.locostv82006-11-02 07:12:51

[slngsht]

 

Do you want a class for un-modified factory built Caterham 7's? Or do you want class for limited modified seven like cars?

 

 

 

Del, Great observation. THIS is the first question we all need to agree on. I'm pretty sure that on this question everyone is not on the same page.

[yellowss7]

Is it safe to assume that in regional events, the DMod class is not a highly populated one? For competition purposes it is great to have someone to compete against. While I have not run across any of the "Super Modified" 7's, I still believe that Tires and Driver skill make the most difference. A slick shod 135hp seven with a competent driver will beat a street tire shod, 200 hp seven. IMHO   And putting both on Slicks, or Street tires, I still think driver skill will determine the winner. Or is that over simplifying it?

 

 

 

Granted I have never competed at the national level. Seperating 7's by tire type at the local level, would possibly end up with one in each class.   

 

 

 

Ergo, to compete you need to be on the same tires as your competitors, and then you need skill to win. Tomyellowss72006-11-02 07:30:03

[Locostdude]

We, IOWA REGION SCCA, are very fortunate to have 3-4 D/E Mod cars with at least 2 drivers each that compete at most local events. Really keeps you on your toes trying to keep up, BUT, leads to continual improvement programs on each of the cars.

 

Del Long

[slngsht]

Is it safe to assume that in regional events, the DMod class is not a highly populated one? For competition purposes it is great to have someone to compete against. While I have not run across any of the "Super Modified" 7's, I still believe that Tires and Driver skill make the most difference. A slick shod 135hp seven with a competent driver will beat a street tire shod, 200 hp seven. IMHO   And putting both on Slicks, or Street tires, I still think driver skill will determine the winner. Or is that over simplifying it?

 

 

 

Granted I have never competed at the national level. Seperating 7's by tire type at the local level, would possibly end up with one in each class.   

 

 

 

Ergo, to compete you need to be on the same tires as your competitors, and then you need skill to win. Tom

 

 

 

K. I'll chime in as another non-competing autocrosser. Del, Michael D, or any of the others who run the nationals have more valuable input than me.

 

 

 

I think in a broad sense you are right that the 2 biggest factors are tires and driver skill. Those amount to 1 (or many cases more) seconds in run times.

 

 

 

However, margins of victory are much smaller. When a tenth of a second seperates the first few positions, can we say for sure that the giant spoiler on one car didn't make a difference? And if we honestly believe it didn't, why was it installed? Just food for thought.

 

 

 

As Del pointed out, his car and probably many others in DMod are results of many years of optimizing, changing, etc... At that level, every improvement is there for a reason. Common sense tells me a Caterham in stock trim that was purchased 10 years ago, and is setup properly, will still be slower than a winged car optimized for autox, given equal drivers, tires, power to weight ratio.

[Locostdude]

I'll add one more thought then I'll go back to lurk mode.

 

This years SCCA National was an anomoly, I think that's how you spell it, in that it was the first time we've all run on that asphalt surface. We, the SPRINTO team, made a good guess by thinking there wouldn't be as much grip as there was on the old concrete surface we've run on for the last few years. We correctly guessed extra weight would probably help our tires get up to temperature faster. The 350 pounds the car was over minimum in D Mod trim made a big difference in grip.

 

The front and rear spoilers were BIG psycological advantage.

 

If you can't out run them, distract them.

 

 

 

Back to lurk mode.

 

Del Long

[Al N.]

Del-I hope you won't be too much of a lurker, as I think your experience would be invaluable to any attempts at codification/standardization of a class. At the very least, check your Private Messages to see if anyone has reached out to you directly. Thanks again for visiting.-Al

[Locostdude]

I'm in enough trouble already, from people thinking I wrote the D/E Mod rules to fit my car, which I did not do. I just try to keep up the the latest revision.

 

 

 

Del Long

[SD-Jacks]

The recent protest in DM at nationals this year have underscored the need of new class for Sevens or another class that accepts Sevens. I am starting this thread as a place for those of us that are interested to discuss our options.

 

 

 

Please chime in.

 

 

 

MichaelD

 

 

 

This thread was started as a search for new class for Sevens. A new class would have rules and likely conflicts. A remedy will be needed to resolve conflicts.

 

The SCCA has set up rules in an attempt to create a level playing field. Unfortunately, no ‘scruttineering’ is done (as it is in SCCA Club Racing), and the only challenges allowed are through protests. Competitors will differ in their personal interpretation of the rules.

 

 

 

Because protest is the only enforcement tool SCCA offers, the D-Mod rules have been contested several times. A few years ago, Del Long protested a fellow D-Mod competitor. That competitor was disqualified and the next year returned with corrective changes—and has run uncontested since then. This protest, although, clarifying one point, left other areas of prep unanswered.

 

 

 

Differences of opinioin, will naturally occur, and as long as SCCA only offers a “protest” as the remedy to rule interpretation, it takes on an element of being personal. The impound and mandatory scrutiny that occurs in SCCA Club Racing..to confirm rule compliance, engine displacement, etc would be less contentious,less personal, more equitable, and likely to encourage compliance.

 

 

[Locostdude]

 

Differences of opinioin, will naturally occur, and as long as SCCA only offers a “protest” as the remedy to rule interpretation, it takes on an element of being personal. The impound and mandatory scrutiny that occurs in SCCA Club Racing..to confirm rule compliance, engine displacement, etc would be less contentious,less personal, more equitable, and likely to encourage compliance.

 

 

http://www.usa7s.com/aspnetforum/images/emoticons/coolgleamA.gif Good point. One thing that might work, for both D/E Mod, and the "new 7" class would be a compliance comittee made up of fellow competitors. They could review all the cars in impound, make suggestions, and ask questions.

 

Del Long   http://www.usa7s.com/aspnetforum/images/emoticons/coolgleamA.gif

[BrianGT]

I don't see the point of creating a new class in the hopes to have a class that the "standard" 7 can be competitive in. I think that it would be better to just have the DM rules redefined, and separate from the prepared rules. With any class beyond the stock classes, there will always be possibility of someone building a purpose built autoX car, taking advantage of all of the allowances allowed by the rule set. I don't see how it would be possible to define a rule set that would allow sevens/locosts/caterhams, and not allow a purpose built car. If you truly want a competitive car and don't want to hack up your seven, leave the seven at home, and drive a competitive stock class car.

 

 

 

As for tires, if you create a new class and restrict it to DOT legal tires, then the tire choice is quite limited in the smaller sizes. The DOT legal tires like v710s favor large cars with large diameter tires when it comes to sizing. There are no wide v710s (>225 width) that have a diameter less than 24.6". If you allow real slicks, then there are plenty of tires choices out there for the sevens.

 

 

 

I don't intend or expect the locost that I am building to ever be competitive in DM on a pax basis/class winning basis, but this won't stop me from building it, autocrossing it and having a good time.

 

 

 

--

 

Brian

[MichaelD]

Brian,

 

 

 

I tend to agree with you.

 

 

 

I started this thread here and on the DMEM site in an attempt to find out:

 

 

 

1. Why Sevens are primairly stuck in DM

 

 

 

2. How they got there.

 

 

 

3. Was there enough interest in a new Sevens class.

 

 

 

I have learned alot about all three points.

 

 

 

Sevens are the SCCA's bastard child because in the beginning they were just to fast for other classes and it is to hard to establish a standard for the car. There are way to many variables between different types of Sevens to create a standard for a "Stock Seven". Rules and excuses have always been established to keep various cars out of other classes. The Sven just happens to be one of them. It would seem to me that there is way to little interest for the SCCA to ever allow Sevens in another class yet alone create a class for Sevens.

 

 

 

Michael D.

[MichaelD]

Steve,

 

 

 

The biggest time difference in tires seems to be with Hoosier slicks. Most cars at Nationals run 13x10 Hoosiers.

 

 

 

This year it was much cooler than usual and the surface was sandy. Many drivers felt that narrower slicks or possibly the DOT radials may have supplied more traction. That discussion is still ongoing.

 

 

 

My bet is that in cooler weather (45 - 65 degrees) the 13x 7s or 8s will be faster while the 13x10s will still be faster in warm weather. That's where my money will go this year.

 

 

 

Then practice, practice, practice.

 

 

 

Have a great off season.

 

 

 

Michael D.

 

 

 

 

[manik]

Since the real differentiation between a 'Seven' and a 'Regular' car is the power-to-weight ratio, wouldn't it make sense to have a weight classification, and then subcategories based on engine displacement?

 

 

 

All this talk of windshields, fenders, wings, tires, etc., really doesn't have too much bearing on performance between Sevens (Westfield, Caterham, Birkin, or Locost). Trying to define a 'stock' Seven sounds impossible, so why not classify them under weight, then power (or vice-versa)? Stipulate that all cars must run street tires, or under the assumption that the lightest cars are track-specific cars to begin with and allow slicks in their category?

 

 

 

The biggest obstacle, from my point of view, is getting any participants to force the SCCA to create a special class.

 

 

 

NASA already has a Se7ens Challenge, no?

 

 

 

And yes, I realize NASA racing is not autocross! http://www.usa7s.com/aspnetforum/images/emoticons/smile5.gif

 

 

 

 

 

tm

 

 

 

manik2006-11-10 15:03:13

[Boxologist]

http://www.motorsportsne.com/

 

 

 

has a list of classes by power to weight ratio.