The NASA ST rules are here: http://www.nasaproracing.com/rules/Super-Touring.pdf
The overall club rules are here: http://www.nasaproracing.com/rules/ccr.pdf
Worth noting is that the ST rules already have the following provisions:
Brunton Stalker (If aero mods, wing, or splitter, then -0.75 modification factor)
Brunton Stalker (If no aero mods, wing, or splitter, +0.75 modification factor)
Caterham & Lotus 7 (if aero mods, wing, or splitter, then -0.75 modification factor)
Caterham & Lotus 7 (if no aero mods, wing, or splitter, then +0.75 modification factor)
Having a traditional locost classed based on the cars above should be fairly simple. It should also be possible to have a middie classed for ST based on power to weight with appropriate modification factors.
The heart of the class spec is:
Super Touring 1 (ST1) = “adjusted” wt/hp ratio equal to, or greater than, 5.50:1
Super Touring 2 (ST2) = “adjusted” wt/hp ratio equal to, or greater than, 8.70:1
The modification factors are:
The “modification factor” listed after each item below is added or subtracted from the actual
measured wt/hp ratio to determine the “adjusted” wt./hp ratio that determines vehicle legality in
each ST class.
Body Type: 4-door Sedan or 5-door Wagon = +0.4
Transmission: Dog-ring/Straight-cut gears (non-synchromesh) = -0.2
Sequential/Tiptronic-like/paddle shift/semi-automatic = -0.2
Drivetrain: AWD = -0.5, FWD = +1.0
Tires: Non-DOT approved tires = -0.75 (VRL & GAC Hoosiers see App. A)
Size 275 to 250 (or 10.5” to 9.6” for non-DOT approved) = +0.4
Size 245 or smaller (or less than 9.6” for non-DOT approved) = +0.8
Competition Weight: Modification factors for weight (with driver) are listed in the ST rules.
Based on the ST rules package a bike engine build weighing in at 1100 lbs with driver could be at or very near the ST2 cap with 138 whp. A car with more power or less weight would probably need ballast to stay within the ST2 spec. It's worth noting that up to 250 lbs of ballast is permitted.
So that's the direction I plan to take my build when it finally gets rolling. I plan to build my car as a replica of a late 60's closed prototype (think along the lines of a GT40 or 906/908) using bike based power.
I think it would be pretty easy to work entirely within the ST rules and still develop a locost sub-class. From this point if we can get enough competitors to build cars to a sub-spec we agree on then moving to a nationally recognized class should be a fairly small step. Even if our effort to develop an effective sub-spec fails, we would all still have cars that could be actively raced in NASA's ST classes.