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PostPosted: February 19, 2015, 5:46 pm 
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A new Yahoo group has been formed to discuss the development of an alternative class to SCCA D Mod or E Mod... If you're interested in a class that doesn't allow any aero additions and requires two side-by-side adult size seats, and which may even allow bike engine cars then please join the group. The discussion so far is that all cars must have current registration and insurance (be truly streetable).

Nothing is decided yet, including the name of the class.

A class that is for street cars that don't fit well into any SCCA class is the thought... Including Ar-i-el Atoms, various kit cars, Midlana, any one-off car, and of course any locost that isn't already optimized for D or E Mod.

Please go to this site to join the discussion.
Here are the details on SLModified:
Group home page: https://groups.yahoo.com/group/SLModified

Dean


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PostPosted: February 19, 2015, 6:48 pm 
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Not sure if a class just for Nationals will ever work but I am interested.

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PostPosted: February 19, 2015, 7:41 pm 
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Hi Paul - National only class was Glen's initial thought... He has since posted a message saying that he and his son Scott talked about things and he is now thinking otherwise.

With at least some regions already having a class the accommodates most all street cars, maybe we can just promote that as a more consistently followed plan. From my point of view, it's just one more thing that I could do with the car I plan to build, so regional only, national only, or both, I'm interested.

Lots to talk about.

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PostPosted: February 20, 2015, 12:10 pm 
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I'm interested, haven't joined the Yahoo group

My local region is once again discussing how to let me run Blood Sweat and Beers. They don't think it's remotely reasonable to lump me into A Mod just because I'm running a bike engine.

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PostPosted: February 20, 2015, 12:28 pm 
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Honestly, I don't see much point in going to a national level competition in a car that will only be laughably uncompetitive in this class, as opposed to showing up and being a insanely uncompetitive in DM. If I'm going to take a car to the compete for a National Championship, I'm going to build as competitive of a dedicated race car as I can, to the fullest extent possible for the rule set of whatever class I have chosen to compete in...In this case, even if that means adding the minimum necessary to meet the 'street legal' requirements. That is the nature of competing at the highest level of any given sport. Even if that's not the intent now, any success with this class will inevitably lead to that. By nature, I wouldn't expect many people will not be content for very long to just run a totally and completely uncompetitive car just for the fun of it, in whatever under-prepped car they happen to already own, at a National Championship level...Which is what it sounds to me is the intent of this class, from all of the information available so far. In my opinion, this class makes much more sense to convince your local/regional club to run, since they are free to create special classes for people who simply want to dabble in the sport with their wildly under-prepped street cars...Like an index class for all cars in race tire classes that are running street tires.

Speaking of which, saying it's for street cars but then not requiring 'street' tires seems contradictory to me. Put a 140-200 treadwear minimum limit on the tires, and this class just got a whole lot more interesting to me, even if my build would still be substantially underpowered. Maybe...MAYBE allow streetable DOT-R's, but preferably true street tires. I think that this would have more success to make it to DM/EM, what ST is to SP.

The 1.8x forced induction multiplier also sounds a bit much to me. Has any forced induction 1.4L dominated DM, even before the recently added restrictions to them? And this proposal would make the same little turbo engines run as equals against naturally aspirated engines that have the potential to make even more power in this class than in DM due to the similarly expanded displacement break point? That doesn't make much sense to me.

Also, has anybody ever tried prepping an At-om to the fullest extent of the DM/EM rules yet, now that the 'kit car' allowance has been added, to know that it's not actually capable of being competitive in DM?

Taking it a step further, for a genuine 'street kit car' type of class, I would probably rather see this set up more like the NASA Super Touring type rules that use a formula based approach to equalizing cars of wildly differing build types.



TooBusy, why AM?...Don't DM/EM cars prepped in excess of DM/EM rules (BEC's) go to BM, or has that changed in the last few years? Not that you'll be competitive there either, but it's at least a little bit better. As long as your local membership doesn't disapprove, and the car isn't on par with national caliber DM performance, the club could still just class you in DM anyways.

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Last edited by Driven5 on February 20, 2015, 1:48 pm, edited 1 time in total.

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PostPosted: February 20, 2015, 1:45 pm 
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Driven5 wrote:
TooBusy, why AM?...Don't DM/EM cars prepped in excess of DM/EM rules (BEC's) go to BM, or has that changed in the last few years? Not that you'll be competitive there either, but it's at least a little bit better. As long as your local membership doesn't disapprove, and the car isn't on par with national caliber DM performance, the club could still just class you in DM anyways.


That's the discussion we're having. Once upon a time BEC's automatically got lumped into BM as a minimum. "The 2015 rules" disallow BEC's. , so they're planning to toss me into AM unlimited class. I could put a 300hp "car" engine in and run EM. :BH:

Just complete and total BS from the SCCA.

The new rule set sure in making it tough to sell Blood Sweat and Beers. I should have listed this little beast before Christmas.

I'm about to say phuck it and put a 1.3l Toyota motor out of a Starlet in place of the R1 and save my motor for a Formula 1000 car.

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OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216


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PostPosted: February 20, 2015, 1:48 pm 
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Justin - If we get enough interest, then we can begin to write rules. I would agree to true street tires, myself. I think others may too, but they're already used to running slicks in DM or EM, so that will require a change in their "normal".

I'm missing something somewhere... I haven't heard any talk of a 1.8 FI multiplier. Is this something from the DMOD-EMOD yahoo group that I missed? I've seen talk of a 33mm or even a 31mm orifice, but maybe I missed something about a new multiplier. For SLM or whatever it will be called, I'd like to see no mention of displacement limits and therefore no displacement multiplier for forced induction.

What I'm thinking would work is a calculation of minimum weight (with driver) based upon displacement (maybe about 750 pounds per liter (a different number for rotary, different yet for electric), and the use of forced induction (maybe a multiplier for this weight calculation of 1.25..?). The numbers should lead to a minimum weight just high enough to remove advantages of using a bike engine. The point being achieving competition that is equal as possible for bike engine or automotive engine. Dealing with differences in "stock" aero may dictate adding in another factor in the calculation of minimum weight. Maybe the multiplier for a car that has some stock aero (or even added aero devices) is 1.1 or 1.15..? Adding 10% to 15% to their weight should tend to equalize things.

This will be the opposite of a spec class. The calculation of minimum weight could be the one equalizing measure. It would never be perfect, but hopefully it could be workable.

The more I think of it, a minimum ride height of 4" and requiring true street tires does appeal to me.

Dean


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PostPosted: February 20, 2015, 2:04 pm 
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TooBusy wrote:
The 2015 rules" disallow BEC's.
There it is...I can't for the life of me figure out why the SCCA is so afraid of trying to reasonably class BEC's.


DeanD3W wrote:
I'm missing something somewhere...
Read the comments from "Glen" in the SLModified group regarding his discussion with "Scott". That's the most information I saw on what the actual intent is for this class, and it sounds a bit to much like for me to see the value in it.

I'm glad to see you on a similar page to me regarding a formulaic approach, but rather than a pounds per liter based calculation...Why not start the calculation from a much more universally applicable pounds per (peak whp + peak wtq)/2? There just needs to be some dyno testing guidelines. After that, pretty much everything else that needs to be dealt with can be based on simple modification factors to that base (power+torque)/2 to weight ratio.

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Last edited by Driven5 on February 20, 2015, 2:35 pm, edited 2 times in total.

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PostPosted: February 20, 2015, 2:22 pm 
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Are dyno results consistent enough to use for minimum weight calculations? If so, great, but I think they vary widely.

Thank you for not clobbering my "maybe 750 pounds per liter" statement... That'd be a bit heavy for a V8 powered car, I suppose. Maybe 2000 pounds for a 5 liter engine, 1500 for a 2 liter, and 1200 pounds for a 1 liter... Something like that. If someone shows up in a little 600cc bike engine street car (stranger things have happened) then I hope they can be part of the class... Maybe at a minimum weight with driver of 850 pounds.

Getting the numbers right won't be so easy, but the benefit of the work could be class with a lot of interesting cars participating.

I like your interest in true street tires because it should lower costs (I hope) or at least remove one more barrier to participation. I'd like to see no restrictions on tire size though.

Dean


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PostPosted: February 20, 2015, 2:35 pm 
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I would recommend a good read through the NASA Super Touring rules to get a better idea of what I would want to see in a misfit toy catch-all class like this. I think it could be more simplified than that for the purposes of this class, and I to like the (power+torque)/2 better than just power based calculation, but it gives a lot of ideas on how a variety of competitive issues like tires and transmissions could be dealt with. Engine displacements are just as easy to cheat as dyno results, if not easier.

The elephant in the room is always going to be how it will even be possible to define and uphold any type of genuine 'street car' status in the class though.

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PostPosted: February 20, 2015, 3:38 pm 
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applicable pounds per (peak whp + peak wtq)/2


My local club is doing something like that too. I guess it bothers me that people want to take measures to make pushrod engines uncompetitive. They fill the engine full of camshafts and valves and then complain because someone just put bigger holes in the block instead of making it complicated.

Let people run simple reliable motors, displacement doesn't have anything to do with the racing. measure the power and be done with it.

What about electric motors? These parts are becoming available and for a short format like an autocross they must be attractive.

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PostPosted: February 20, 2015, 4:35 pm 
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Now a street tire Mod class is something I would really be interested in. Street tires are very good much easier to drive closed to the limit. They are cheaper, last longer and can be user relatively well in the wet. I would definitely prefer the class to run on street tires.

I prefer racing my Rx8 on street tires even though it is not as quick I just love the way the car moves on street tires. Racing Scrap Metal on Street tires would be a blast.

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PostPosted: February 20, 2015, 6:58 pm 
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horizenjob wrote:
Let people run simple reliable motors, displacement doesn't have anything to do with the racing. measure the power and be done with it.
I agree that displacement results in a poor method for determining weights. If anything, cumulative valve area would probably be a better predictor of performance potential, and is one that I might also consider as an option worth investigating. I believe this has something to do with where the 1.4x OHV displacement advantage came from in EM, even if it was never applied to 2V OHC EM engine or at all DM. A quick check on 2V vs 4V Ford Modular engine valve areas yields a 1.38:1 to 1.39:1 valve are ratio depending whether you're looking at just intake, just exhaust, or both.

But displacement does still have something to do with the power to weight ratio too. A straight pounds per hp limit distinctly favors high torque (large displacement) engines. Think about it, which would be faster between two cars of equal power to weight ratio? The one that spikes to peak hp at one narrow point on the curve, or the one that has a nearly peak plateau in the 'curve' over half of its rpm range. That's why I specifically would be interested in seeing how a measure like the unconventional (hp+tq)/2 concept might be used rather than just power.

Another potential option could be specifying a single inlet restriction size based on vehicle weight, but I don't think many people would care for that if they are actually driving 'street' cars.

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PostPosted: February 20, 2015, 7:47 pm 
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seeing how a measure like the unconventional (hp+tq)/2 concept might be used rather than just power.


It means that the cam is selected for this (out of hundreds available ) and then instead of a carb you use an EFI that you adjust for this and then put in some big valve springs. The pushrod V8's don't have any lack of parts available to them but it seems a pity to just have to toss an extra couple thousand dollars of parts into something that could be the most affordable build.

I don't know how to even everything out so everyone gets to have fun, that's the hard part...

On the modern engines first thing to do will be to disconnect the VVT stuff.

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PostPosted: February 20, 2015, 8:09 pm 
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horizenjob wrote:
I don't know how to even everything out so everyone gets to have fun, that's the hard part...
I'm not sure I follow. This is exactly what my suggestion is attempting to address...I don't think pushrod engines should be regulated into an over-competitive position any more than they should be regulated into an under-competitive, regardless of how cheap they are to make perform.

I don't think that factoring the torque (and/or maybe the rpm at which the peak horsepower is made?) into a potentially more accurate representative performance calculation would result in any degree of unfair burden on pushrod V8 engines either. I dare say it would be even more of a pity for people to have to spend thousands of dollars completely changing out their existing non-pushrod-V8 drivetrain to a pushrod V8 in order to be competitive, especially considering the loosely defined intent of such a class so far.

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