We published a brandy-new philosophy mid-2011; that's what you see in the opening paragraphs of the STCS (compare it to the January 2011 GCR version). Apparently, it's lacking in this area. This is obviously a topic that deserves clarification of intent, or at a minimum maybe even a complete re-think to the intent itself.
Take some time to put something together and send it in.
GA
For quick reference, here it is:
9.1.4.A. Purpose and Philosophy
The intent of the Super Touring category is to allow competition of production-based vehicles, at a higher level of preparation, using DOT-approved tires. Vehicles used in this category must be identifiable with the vehicles offered for sale to the public and available through the manufacturer’s distribution channels in the US. No chassis or engines older than 1985 will be eligible, except that model runs that began before 1985 are eligible (e.g., if a model was produced in 1983-1988, the 1983 and 1984 cars are eligible). The SCCA does not guarantee the competitiveness of any car.
Super Touring Over (STO) vehicles are high-performance GT and exotics over 3.2 liters. STO vehicles are explicitly approved for competition; to be eligible for STO competition, a chassis and maximum engine displacement must be listed as a specially-approved combination in the STO "Approved Cars and Engines" table.
Super Touring Under (STU) vehicles are mid-level multi-purpose performance cars of 3.2 liters and under. Case-by-case approval of engines over 3.2 liters from "Pony Cars" or "American Iron" with stock camshaft lift at a heavier weight will be considered. No engines over 4 liters shall be allowed under any circumstances. Spec lines are not required for STU eligibility; unless otherwise specified, any vehicle meeting the model year and engine displacement limits is eligible for this class.
World Challenge vehicles compliant to a SCCA Pro VTS may be approved on a case-by-case basis for STU. See the STU "Approved World Challenge Cars" table.
Super Touring Light (STL) is a small-bore "tuner" class with engine displacements of 2.0 liters and under. STL encompasses a lower level of allowed modifications compared to STU and STO. As with STU, spec lines are not required for STL eligibility; unless otherwise specified, any vehicle meeting the model year and engine displacement limits is eligible for this class.
Alternate allowances may be approved on a case-by-case basis for individual vehicles that do not meet these parameters; see "Alternate Vehicle Allowances" tables. Engines components from these approved vehicle allowances may not be installed in other chassis without specific line-item approval (e.g., the STU 3.8L Mustang engine may not be installed into a Ford Focus).
Vehicle modifications are limited to those listed herein. Unless a particular modification or part is approved in these rules, the vehicle and all of its relevant parts and assemblies shall be stock for the correct make and model of car. Some amount of latitude will be considered to facilitate engine installations, however if extensive modifications are required it is recommended to seek clarification from the Club Racing Board. Replacement parts may be obtained from sources other than the manufacturer provided they are the exact equivalent of the original parts. The intent of this rule is to allow the competitor to obtain replacement parts from standard industry outlets, e.g., auto-parts distributors, rather than from the manufacturer. It is not intended to allow parts that do not meet all dimensional and material specifications of new parts from the manufacturer, unless otherwise allowed in the Super Touring category or class rules.
Each class will have a baseline target power-to-weight ratio. Weights may be adjusted or cars may be subject to changes in intake restrictors to meet these targets. Cars may be required to carry data acquisition equipment for review of performance.
