Application of E-Production Racing Rules to the EPMiata.Com Race Car.

Production Car Racing in SCCA What it is

If you'll allow me to oversimplify, SCCA™ race cars can be broken into production vehicles, spec racers, and formula cars. Of these three classes, production cars are those that have been mass produced (ie, that you could at one point buy at a dealership.) Of these cars, there are three categories: Improved Touring (IT), Production, and Grand Touring (GT). These three classes have progressively more liberal rules on performance and handling modifications and progressively more stringent rules on safety.

Production Cars are broken down into limited prep (or level 2) and full prep (or level 1). I will attempt to avoid all of the many political debates that we could quickly fall into by again oversimplifying. Generally, a platform (make, model, and year of production car) that is introduced into the Production category is introduced as limited prep. This allows the rulemakers to introduce the car with a very limited set of competition allowances that will ensure that the car isn't suddenly dominating its class. Once competition allowances have been granted, it is much more uncommon for them to be removed. SCCA tends to like to "sneak up" on the combination that allows a car to be competitive. (And, as they will quickly tell you, they do not guarantee that any car will be competitive.)

This isn't to say that a car at limited prep will ever become full prep. Even if it is dog-slow, SCCA is not going to grant full-prep status to a vehicle that is the only one of it's kind being raced in the program. So, if you're driving an '77 Yugo Boom, no amount of petitioning is going to get them to grant you enough allowances to be nationally competitive when you're the only one that is racing that car. Similarly, if the car comes from the factory with enough performance capability to be very competitive with a limited amount of preparation, then no additional competition allowances will be granted. SCCA's center of gravity, if you will, is limited prep. They are "committed" for the future of Production Car racing to the Level 2 Formula (whatever that means.)

I'm not aware of an exact definition that differentiates limited and full prep on a broad basis. That is done at the individual vehicle level across a broad range of criteria. Examples of the criteria that SCCA specifies for Production Car Racing:

Engine Size and Configuration
Horsepower Potential
Driveline Components
Brakes
Car Weight
Suspension Configuration
Wheels
Body Style

The EP Miata is one such example of a car that is specified at two levels of preparation in the same class. So, if you want to race a 1995 Mazda Miata in the Production category, you are limited to E-Production. (F-Production is available to the earlier 1.6l Miata too, just to make sure you're confused.) Within E-Production, we had a choice to make with our '95 Miata. One version is a combination of full and limited (level 1 and level 2) preparation and the other is strictly level 1 (limited) preparation. Why would anyone go strictly level 2 when they could go with the combination of level 1/2? Because the Level 1 EPMiatas are granted certain compensations for being limited prep (namely, about 150 pounds less wieght) and your situation might limit you to a situation more consistent with the allowances given by the Level 1 EPMiata. However, it is our feeling that we can take the weight penalty that comes with Level 1/2 along with the increase competition allowances and be more competitive.

Here is a quick breakdown of the two lines within the E-Production Rules that apply to our car. I've left out some of the "duh" ones (like engine material: aluminum).

Vehicle	Mazda Miata 90-97 1.8l	Mazda Miata 94-97
Prep Level	1/2	2
Weight (lbs)	Carb: 2175 FI: 2225	2075 2101* 2153**
Bore x Stroke (mm)	83 x 85	83 x 85
Displacement	1840	1840
Valves	Intake: 33.1 Exhaust: 28.2	Intake: 33.1 Exhaust: 28.2
Carb # and Type	2x Automotive Sidedraft w/32mm Choke and IR Manifold, or Fuel Injection	Fuel Injection
Track (F/R)	58.4 / 59.4	58.4 / 59.4
Brakes Std (F/R)	235mm Vented Disc / 231mm Solid Disc	235mm Vented Disc / 231mm Solid Disc
Brakes Alt (F/R)	254mm Vented Disc / 251mm Solid Disc	254mm Vented Disc / 251mm Solid Disc
Notes	Compression Ratio Limited to 12.0:1. Valve Lift .500" Max. Drivetrain Level 2 Prep Only. Listed spec line weight does not change with alternate or stock transmission. Level 1 Dry Sump, Connecting Rods, Intake Manifold Porting, Crankshafts, Rocker Arms, and Cam Followers. OEM Hard Top Allowed.	Compression Ratio Limited to 12.0:1. Valve Lift .500" Max. Level 1 Dry Sump, Connecting Rods, Intake Manifold Porting, Crankshafts, Rocker Arms, and Cam Followers. OEM Hard Top Allowed.