B-mod 101?

[teamfour]

Can someone give me the basics on the rules and/or car eligibility for B-mod? The SCCA rules aren't very clear. I have an F-mod car converted to GSXR 600cc power and really don't want to run A-mod.

[lowside67]

Can someone give me the basics on the rules and/or car eligibility for B-mod? The SCCA rules aren't very clear. I have an F-mod car converted to GSXR 600cc power and really don't want to run A-mod.

As I read the rules, the only way you are legal to run B-mod is if your car is homologated as a "Formula Special" (FS) car. The description for B-mod starts off with "All Formula Cars or Sports Racers legal under the current year GCR, unless specifically classed elsewhere, with the following exceptions" As I understand it, your car isnt legal under the current GCR as it is not homologated for any class since it is no longer an F500 car. Otherwise, I think you will have to run in A-mod.

[teamfour]

Thanks Mark.

[Viperklr]

Lee,

I gotta agree with that interpretation.

What happens though if/when this new F500/600 thing goes through? Sounds like they are pushing to initally get FS homologation for these cars? If you went that route, could it then run B Mod? Maybe even down the road F mod will open up to these cars?

[Stan Clayton]

It is very easy to add FS to your current F5 homologation. Just download the appropriate homologation form from SCCA's website and send it in. Stan

[Rick Kirchner]

Does "legality" imply a homologation requirement? What about all those B-mods that were "F5000" because F5000 had virtually no rules? What would you homologate a F5000 to, or for that matter, any defunct class? did all the SVs running in FA suddenly have to come up with the paperwork?

I think "class legal" and homologated are two separate things.

[formulasuper]

Does "legality" imply a homologation requirement? What about all those B-mods that were "F5000" because F5000 had virtually no rules? What would you homologate a F5000 to, or for that matter, any defunct class? did all the SVs running in FA suddenly have to come up with the paperwork?

I think "class legal" and homologated are two separate things.

Yes, SV's do have to have FA homologation to run in Formula Atlantic. Homologation is just one requirement of many to be class legal in formula & sportsracer classes.

[teamfour]

Homologation is just one requirement of many to be class legal in formula & sportsracer classes.

Scott, you bring up the second half of my 101 question.

So I send in the homologation paperwork and get approved. But what about minimum weight, wheelbase, track, etc., requirements? There has to be more to this than homologation.

[lowside67]

Scott, you bring up the second half of my 101 question.

So I send in the homologation paperwork and get approved. But what about minimum weight, wheelbase, track, etc., requirements? There has to be more to this than homologation.

All the requirements with respect to what you are asking - minimum weight, wheelbase, etc. are all part of the road racing specifications for the "Formula Special" class. Go to SCCA's website and look it up under the road racing section.

-Mark

[teamfour]

Thanks again Mark. It looks like I am good for FS and subsequently B-mod if I can get the weight up to 1020 with driver.

[lowside67]

Thanks again Mark. It looks like I am good for FS and subsequently B-mod if I can get the weight up to 1020 with driver.

Just curious about your motivations behind all this. I suspect you know that at 1020lbs and no wings your car is likely not a front runner for SCCA purposes in BM. Why bother re-homologating as FS and going through all this instead of just running AM?

[teamfour]

When my car ran as FM, I would usually beat the BM class and set FTD at most local/regional events. You are probably right about the weight disadvantage in BM, but 1020 is the lowest weight you can run in the class. I guess my motivation is that I may not be too far behind in BM; I know for sure I will be WAY behind in AM. Another factor is that their are no AM cars in my area. So I could go out and run by myself and always win the class, but that is no fun. At least in BM I would have someone to run against locally.

[Stan Clayton]

Thanks again Mark. It looks like I am good for FS and subsequently B-mod if I can get the weight up to 1020 with driver.

I'm not sure where the 1020 lbs with driver comes from (maybe Solo rules?), but for FS the car without driver must weigh 750 lbs unless your homologation certificate states otherwise. Hint: request a lower weight (whatever your car actually weights ready to race, but with all the fuel pumped out of it) on the homologation forms.

[teamfour]

I'm not sure where the 1020 lbs with driver comes from (maybe Solo rules?),

From the SoloRule Book for BM:

C. Sports Racers and All Open Wheel Cars Including Formula
Atlantics
1. May use any automotive based 2-valve motor up to 1300cc,
any 2-stroke motor up to 900cc, any 4- or more valve motor
up to 1005cc. Minimum weight: 1020 pounds.

Thanks for the hint.

[teamfour]

At the risk of beating a dead horse, I wanted to give my final observation so others may learn.

The Solo rules deviate from the GCR in areas to allow older, non-competitive cars to continue to have a forum in which to compete. Thus I found my Catch-22.

Solo does not require FIA fuel cells, nor does it require larger main roll hoops as specified by the GCR. However, in order to homologate my car as an FS leading to solo BM, I must have the fuel cell and larger roll hoop even though they are not required in Solo. Got it?

A-mod it is.

[Craig Henry]

Teamfour,

The car doesn’t need homologation or logbook paperwork to compete. "Legal" to a GCR class (other than the solo II exceptions) but no paperwork required. Many solo only cars have been converted from one GCR class to another and not re-homologated.

Craig

[teamfour]

Thanks Craig, that makes sense.

[Rick Kirchner]

That's what i was getting at.

[B17overhead]

Your car as it is set up currently could actually be a competitive BM car at the slower events. With upgrades such as wings and forced induction or a 1025cc motor, it could potentially be Nationally competitive.

A 85 mph slalom in a solo BM car is very much like a 85 mph sweeping corner in road racing as far as aero is concerned. So at all faster events, aero really defines a BM car's performance.


1) Hologation is not required in any solo class except CM.
2) The basis for the most current solo BM wording is that fomula cars and sports racers all run equal weights for equal displacements.

It makes no difference where the car came from in road racing and what year GCR it originally ran under. Forget the designations for FS, FA, DSR, CSR, FB,, FC, ASR, FF2000, Even Solo DM and EM street derived cars can run in BM. Just match up the car's weight and displacement to the solo rule book BM rules.

Then, open wheel vs. closed wheel is what determines the aero rules that apply.

The cc break points in BM were meant to copy or encompass many existing GCR cc break points.

The weights also parallel the GCR to some extent, but because many diverse GCR classes are supposed to run with parity in BM solo, BM solo weights do not always follow the GCR.

3) You have the weight correct (1020 lbs w. driver) for a 600cc formula or sports racer since it falls under the 1025cc MC motor displacement limit.

Also, since it is an open wheel car, the current year GCR aero rules from FA apply.

If the car were a sports racer, the current year GCR aero rules for DSR would apply with the notable solo over-ride that total wing area (F+R) on the car must be under 8 foot square. Under-nose diffusers, splitters, rear diffusers, tunnels, or sloping bodywork does not enter into that 8 foot square calculation.

A 600cc engine is also under the displacement limit for forced induction on a 1020 lbs car in BM, so you have that option. (1025/1.4=732cc max)

4) No fuel cells are required in in any solo class.

5) Roll hoop tubing minimum size and and helmut height vs. roll hoop rules are different in solo. See the solo rule book modified class section and the appendix.



Chuck Voboril

[teamfour]

Chuck, thanks for taking time to explain all the particulars for me. You have helped me in the past and I appreciate the continued support.

[lancer360]

A 600cc engine is also under the displacement limit for forced induction on a 1020 lbs car in BM, so you have that option. (1025/1.4=732cc max)
Chuck Voboril

Hmmmm... Turbo Zink sounds good Lee!!!

[NickJ]

Bumping this back up as I have a few questions

Whats the current deal with Formula Cars in BM? Is it possible to keep up with Clemens with an F1000/FB? Seems as if these are easier to find than a Legrand

Can I narrow/shorten any car as I see fit to make it more Solo worthy or do I have to stick with the manufacturer dimensions? (I have absolutely no issue with cutting cars apart - which apparently is a no-no to some formula owners or so I've been told - sorry guys).


I understand the minimum weights and aero rules - just wondering if there is a way I can make an FB fast enough to compete with a 58" wide Legrand.

[PCalhoun]

duplicate post

[Jim Garry]

There's a new B Mod aero rule out for member feedback:

[FONT=ArialMT][FONT=ArialMT]- Per the MAC, the following rule change proposal is presented for member review and comment:[/FONT] [/FONT]

[FONT=ArialMT][FONT=ArialMT]- In Appendix A under MODIFIED CLASS B (BM) change subsection F to read as follows:[/FONT] [/FONT]

[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]F. Aerodynamic restrictions for Formula Atlantic (all open-wheel in BM) shall follow the current GCR with the following [/FONT][/FONT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]Solo allowances:[/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]1) Wings front and rear shall not exceed sports racer maximum aero height[/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]Front wings shall not exceed overall front width as measured at the tires, and width of rear wings shall not [/FONT][FONT=Arial-ItalicMT]exceed 43.33”. Vertical Gurney flaps on endplates are not included in these widths.[/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]3) Sidepod or other parts not considered chassis are not required to attach or stay above a line situated 1 cm [/FONT][FONT=Arial-ItalicMT]above the chassis bottom (this is an excetion to GCR 9.1.1.A.1.g.10).[/FONT] [/FONT]

[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]4) Ground sealing is permitted on cars 66” or wider at the rear tires and which also meet a weight of 1180#.[/FONT]

[/FONT][FONT=ArialMT][FONT=ArialMT]Also change the last sentence of subsection H to read: “All cars must prepare to Formula Atlantic aerodynamic rules [/FONT][/FONT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]as [/FONT][/FONT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]specified in F.” [/FONT][/FONT][FONT=ArialMT][FONT=ArialMT](ref #2660, 2706, 2719)[/FONT][/FONT]

[Jim Garry]

IMO, under current rules some formula cars might be competitive already. Ever since the HPT debacle all of those cars quit and so far haven't been back save for one in '09.

But if the above aero rules are approved, I think formula cars stand a reasonable chance of winning.

[PCalhoun]

Bumping this back up as I have a few questions

Whats the current deal with Formula Cars in BM? Is it possible to keep up with Clemens with an F1000/FB? Seems as if these are easier to find than a Legrand

Can I narrow/shorten any car as I see fit to make it more Solo worthy or do I have to stick with the manufacturer dimensions? (I have absolutely no issue with cutting cars apart - which apparently is a no-no to some formula owners or so I've been told - sorry guys).


I understand the minimum weights and aero rules - just wondering if there is a way I can make an FB fast enough to compete with a 58" wide Legrand.

Running to GCR F1000/FB spec you will be down horsepower and weigh 100# at minimum more than Clemens DSR based car.

However, if you build a car to GCR FS specs you can run at the same weight (900# w/ driver) and open up your engine specs, as specified in Solo B Mod rule H. That said I think it will be difficult to get an F1000 car down to 900# w/ driver, which is 100# less than their road racing weight.

I agree F1000 would be an awesome Solo car, unfortunately I think the short wheelbase LeGrand w/ a modern MC powerplant has moved the bar too high. Hence all the Atlantic cars that never show up anymore since Saunders arrival and now Clemons.

Come play w/ us in CM where FF1600s are plentiful.

2010 Solo Rulebook- B Mod, Pg 222:

[FONT=Arial][FONT=Arial][FONT=Arial]<<H. Formula S - Must weigh appropriate Solo DSR weight if engine size[/FONT]
[FONT=Arial]is within DSR class limitations. FS shall run to the appropriate Formula [/FONT][FONT=Arial]Atlantic rules if engine is larger than allowed in DSR. All cars [/FONT]][FONT=Arial]must prepare to Formula Atlantic aerodynamic rules.>>[/FONT][/FONT][/FONT]

[NickJ]

Come play w/ us in CM where FF1600s are plentiful.

Bbbbbbbut they look like bobsleds with wheels!

Thats what my GF told me when I showed her a pic of a DB1 - I'm not exactly in love with the looks either so thats why I'm in nerdy engineering mode with all these questions.

[NickJ]

Running to GCR F1000/FB spec you will be down horsepower and weigh 100# at minimum more than Clemens DSR based car.

I thought all the 1000cc BM cars had to run at 1020lbs? Or are you just saying that the car would be near impossible to get down to that weight and would more than likely weigh near 1100lbs?

[-pru-]

Bbbbbbbut they look like bobsleds with wheels!

As the owner of a DB-1 this made me laugh!

I would love to give the FB Photon a try in BM:

[PCalhoun]

Bbbbbbbut they look like bobsleds with wheels!

Thats what my GF told me when I showed her a pic of a DB1 - I'm not exactly in love with the looks either so thats why I'm in nerdy engineering mode with all these questions.

You must have shown her an FM SoloVee Because I've never heard anyone not think a DB1 was a sleek, sexy looking racecar. See our threads on SCCAForums regarding getting into CM.

[PCalhoun]

CORRECTION: I got ahold of Clemens and his min is 1020 for Solo NOT the 900 as specified in the GCR fo DSR. Damn that car has to have alot of ballast!

Here are the weights of the BM field at Nationals this year:

[FONT=Arial][FONT=Arial]BM 11 1974 LeGrand DSR 1020 1201 1199[/FONT][/FONT][FONT=Arial]

[FONT=Arial]BM 21 1976 LeGrand MK 18 1020 1036 1030[/FONT]

[FONT=Arial]BM 36 1979 LeGrand MK25 1285 1295 1298[/FONT]
[FONT=Arial]BM 38 2009 Zombie Woof III 1020 1103 1116[/FONT]
[FONT=Arial]BM 49 1976 LeGrand MK18 1020 1036 1037[/FONT]
[FONT=Arial]BM 99 1997 LeGrand Dragon 1020 1029 1022[/FONT]
[FONT=Arial]BM 121 1976 LeGrand MK 18 1020 1057 1057[/FONT]

[FONT=Arial]BM 149 1976 LeGrand MK18 1020 1034 1034[/FONT]
[FONT=Arial]BM 199 1997 LeGrand Dragon 1020 1029 1020[/FONT]

[FONT=Arial]You still would want to build to FS specs, as oppossed to F1000 as this would open up your motor potential for comparable power. Being that you have to weigh the same, I would say at Lincoln things would be much more competitive than at HPT, as Jim notes.[/FONT][/FONT]

[-pru-]

H.13. Minimum weight
Minimum weight is 1000 lbs.

[PCalhoun]

H.13. Minimum weight
Minimum weight is 1000 lbs.

Solo rules take precident, however, thus the difference (and confusion). It is 1020# for BM as outlined in C.1 on pg 222.

[Herman Pahls]

I find this discussion interesting since I have recently inquired about using my F-1000 as a BMod.
I appreciate Auto-X since that is what got me into roadracing but the lack of seat time and the fact that I live 3 hours from the nearest Auto-X events is my major issue. The drivers at the Nationals race a total of 6 minutes over 2 days not including time on a practice track one can apparently sign up for.
I know what I just said sounds like a downer but I am still interested in attending a National and might as well take a car. I am sure the comraderie and 1200 cars could be infectous.
Auto-X drivers are specialists at what they do and most of us road racers would be hard pressed to duplicate their times if able to drive their cars let alone our own cars that need to be set up.
Our F-1000's are within 20 pounds of minimum and one could have a motor built just for Auto-X or borrow one from your DSR friends.
For sportsracers if an engine is larger than 1000cc's ?? but under 1600cc's ?? the car needs to weigh 1180#'s ??.
Does anybody know if this would apply to the f-1000 if ballasted to 1180?
I would consider installing a Hayabusa (I already have one) if the rules allow in the f-1000 since I find more torque easier to drive.
Yes the smaller cars will have advantages but I am told the recent venue change to Lincoln, NE is faster and more open and would fit our cars better.
Before cutting up F-1000's to make them smaller a bunch of F-1000's should show up and see what we are missing.
I already learned that we most likely need to soften our wheel rates.
Gear the cars for approx. 110 MPH in 6th to allow 2nd and 3rd gear.
It sure seems that if a Geartronics could be set up to automatically shift up and down it would be helpful and no one will debate the legality.
Thanks Herman Oregon 541 404 6464 kpahls@frontier.com

[NickJ]

Peter thanks so much for indulging my curiosity with all the questions recently.


Next one - whats the difference between FS and FB engine specs? (I'm unfamiliar with the GCR and I'm horrible at reading PDF files on the computer)

[NickJ]

You must have shown her an FM SoloVee Because I've never heard anyone not think a DB1 was a sleek, sexy looking racecar.

We're both in our mid-20's so our point of reference for "sexy" is probably different than most racers

Put wings and sidepods on a DB1 and I'll agree with you - but I'll go with bobsled on wheels sans those items

[PCalhoun]

Next one - whats the difference between FS and FB engine specs? (I'm unfamiliar with the GCR and I'm horrible at reading PDF files on the computer)

In basic terms FS is a Regional Only 'catch-all' class for formula cars NOC. This would include motorcycle powered cars, or those w/ modified engines, a DSR spec motor for example. Where F1000/FB requires stock engine internals as outlined in H.4 on pg 279 of the GCR.

FB or DSR competitors would better be able to answer questions about the differences in engine preparation, but I suspect the power difference is substantial.

If you are serious about building a modified Solo car competing in BM, CM, or FM you will need to familiarize yourself w/ the GCR, which is available as a PDF download off scca.com. The 2011 edition should br available in January, as I know the BOD is meeting this w/e to finalize some things.

[NickJ]

I took a look at the GCR last night - FS has wide open engine rules, FB must retain stock internals.

Thanks guys.

[ffrgtm]

This thread really interests me as I'm trying to move up into bmod because I want to switch to a hand clutch to force me to learn lfb. I'm certainly not a top level driver so I'm not super concerned with being lincoln competitive, but will a more modern FB wheelbase (~100") and width be too much of a handicap to even consider it?

It seems like it's impossible to find a legrand, and I think I'm too tall for the photon.

[PMD]

I am new to this site, but here primarily to sort out the BM question. My kids and I have been racing F125 for years - until some (I will refrain from using the words I am thinking) at ASN decided that we are using the SCCA rulebook - EXCEPT for the parts that define F125. Since then, have not been able to bring myself to run a door slammer, so it was between soloV in FM (I am a VW guy - and have been for over 4 decades) and BM. Like everyone else, I though I would just score a old roller leGrand...yeah, right. Then I thought I might just as well build a similar gate friendly size BM (remember - accustomed to F125 lines) but a buddy sold me a 65F Crossle frame (slightly bent, no biggie), so I am thinking of using that to make a tunnel car.

Our venue is fairly large, a bit rough in places, so I guess my question (somewhat related to the OP topic) is how does it come down between the small F500 or old school DSR size planform vs. the potential aero from a current size big fat DSR play out.