Maybe I shouldn't call it a championship yet, as I'm not sure we're quite ready for that, but here are the Trans-Am themed rules that I've divised (with some help of the other GRM B-Spec racers).
First of all, an explanation: The goal here is to make cars that are a reasonable facisimile of the "Golden Era" Trans-Am cars. That is to say, we're trying to get performance as close as possible, but not worrying too much as we want some adjustability and freedom in set up and tuning, and Forza 4's car selection is very "best-of-the-breed" biased, resulting in many cars exceeding the displacement limits that they historically competed in.
Turn up the volume, it's the start of the Trans-Am rules on GRM!!!
Thanks Bob, first up, eligible models:
Other cars will be considered based on feedback from participants and an evaluation race evening in the provisional classes (in game, if you aren't bothering to play online, I'm not too bothered to listen to your opinions as you are clearly not the participating audience, no offense implied).
Over 2.0 Liter Class (500 PI MAX, B Class)
1965 Ford Mustang GT, 1968 Dodge Dart HEMI Super Stock, 1968 Shelby GT-500KR, 1968 Pontiac Firebird, 1968 Plymouth Barracuda Formula-S, 1969 Chevrolet Corvair Monza, 1969 Chevrolet Camaro SS, 1969 Chevrolet Camaro Z/28, 1970 Chevrolet Camaro Z/28, 1970 Dodge Challenger R/T, 1970 Mercury Cougar Eliminator, 1970 Ford Mustang BOSS 429, 1971 Plymouth 'Cuda 426 HEMI, 1971 AMC Javelin AMX, 1971 Ford Mustang Mach 1, 1971 BMW 3.0 CSL, 1973 Firebird Trans-Am SD-455, 1973 Porsche 911 Carrera RS.
Provisional O2 Class (500 PI Max, B Class)
None
Under 2.0 Liter Class (425 PI MAX, C Class)
1965 Alfa Romeo GTA Stradale, 1966 Lotus Cortina, 1969 Nissan Fairlady Z 432, 1969 Toyota 2000GT, 1970 Porsche 914/6, 1971 Nissan Skyline 2000GTR, 1971 Lotus Elan Sprint, 1973 Ford Pinto, 1973 Datsun 510, 1973 BMW 2002 Turbo*
*requires that you engine swap the E30 M3 motor, then swap back to the base engine, this removes the turbocharger, then tune normally.
Provisional U2 Class (425 PI MAX, C Class)
Normal