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"Prototype" vs. "Non-production" clarification


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In the rules, the definition of a "prototype" is very vague, and could have significant overlap with "Non-Production vehicles", which have vastly different mod factors.


Obviously, a LMP3, wolf, stohr, elan DP08, etc are prototypes


Obviously, a production corvette with tube frame conversions would be considered a non-production vehicle.


But what about everything else in between that has not been specifically called out in the list of mad factor vehicles?


For example: 

factory five 818R

or an Ariel Atom

Or an old sports racer 2000 (in the 80's this was a prototype car, but it is nowhere near the aero sophistication of the modern prototypes)

Or, a custom tube frame car with custom fiberglass bodywork that I build in my garage?


At what point does a custom built car go from being non-production to being a prototype? Does it have to do with the appearance? Aero features? number of seats? roof or no roof? etc.



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  • 4 weeks later...

I've been wondering the exact same thing. I have a Factory Five  818R in the NW, and there are 3 others racing there. Three race in our SPM class (equivalent to NASA non-production) and one races in the sports racer endurance class. I'd like to race in NASA NorCal in 2019 but not if my 818R has the sports racer modifier.  I've also considered building a car for the Thill25 that would be a custom tribute of a early 60's LeMans 2 seat racing coupe. Again it would be a fun car in E0 from the ST3 base classing, but wouldn't stand a chance in ESR or in ST3 with the prototype modifier. 

I agree, there needs to be a better definition of what is a prototype and what is non production. 

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I guess that a prototype is going to be produced in bigger numbers some day, while a non-production model is never going to be? For example, if we're to compare to aircraft, the Lockheed JSF demonstrator was a prototype because it's being produced as the F-35, while the X-15, a pure record/scientific plane, was a non-production plane.

Now I know it's blurred in terms of cars, especially if we're talking about customs...

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You are misunderstanding what we are referring too.  We are referring to "prototype" in the racing sense, not the engineering R&D sense.

Key examples:

Prototype: LMP1, LMP2, LMP3, IMSA DPi, SCCA P1 cars, SCCA P2 cars, etc.

Non-Production cars: Nascar style tube frame car, TransAm TA2 cars, SCCA GTL cars, etc. (These all "look" like cars, but have custom steel tube frames)


What I am asking for clarification on, is how to judge if any given custom steel tube frame (or carbon / aluminum monocoque) car with custom composite bodywork is a "prototype" or is just a "non-production" car.

This method of judgement / differentiation could then also be easily applied to existing cars in the grey area (factory 5 818R).

Hopeing Greg G. will weigh in...

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  • National Staff

Start with the rule:

"Sports racers, “Prototypes”, and monocoque chassis purpose-built race cars are permitted in ST1 and ST2 using the specific Modification Factor listed for these chassis in 6.5.2."

So, unless listed, ANY sports racer or Prototype or monocoque chassis falls under this rule--regardless of how old it is or whether there are better Aero versions of sports racers now than 20 years ago. 

In regard to the 818R.  Here is a photo of the street car (which would be Non-Production also based on the eligibility rules).  Below is a photo of the race version.  Looks like windshield removed, splitter, canards, and wing added, and "cage" added.  All of those are typical things done to street cars to make them race cars.   Nothing I see there would make it a Sports racer or prototype.   Maybe someone else can prove otherwise--always willing to listen to opposing ideas.

In terms of the rule itself, If it look like a duck, and quacks like a duck, it just might be a duck--unless someone proves its something else (as in the above).   However, for the most part, you did a good job of listing a bunch of vehicles that would all be listed as Prototypes.....


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