Spec E30

Spec E30 is a class of racing cars used in National Auto Sport Association (NASA) road racing events.
Concept.
The goal for Spec E30 is to create high levels of competition among similarly prepared BMW E30 3 Series cars at a reasonable cost. It is intended to encourage low-cost, entry-level, production car based competition. It has been called "the next "big thing"" in club-level racing by "Grassroots Motorsports Magazine".
Cars.
The series consists of U.S.-spec BMW E30 325i coupes and sedans, sold between 1987 and 1991. All cars in the series use the BMW M20B25 engine. Convertibles built to series specs and with log books issued prior to November 1, 2011 are still allowed to compete, but this model has been sunsetted out of the series.
As a "specified" class, the rules allow for a limited number of modifications, predominantly involving required suspension parts.
Required components include:
Allowed modifications include rebuilding of the original BMW motor, but it must follow factory specifications. And even then, there is now a reward weight system that is used based on the actual output from a sanctioned dynometer (maximum class allowed is 162.9). As well, a model dyno plot is used to compare all competitors engine output for distinct anomalies.