P2 Spec Line Cars - 1005cc Engine FPIR Change Request
#34947 from Eric OBrien · Not recommended · Minutes (2023-12 Fastrack)
Thank you for your letter. The Club Racing Board does not recommend this change. The SCCA Power Factor formula and the
collection of on-track data for use with a Balance of Performance (BoP) standard have allowed the CRB to fine-tune performance
levels in the P2 class in recent years. While this system is not perfect, it has helped to maintain parity between the types of cars
from which data has been collected. The current rules have resulted in a good balance among the cars that participate in U.S.
Majors Tour events and at the Runoffs level. The request to eliminate flat plate intake restrictors on 1005 cc and smaller engines
for all Spec Line Cars to improve their top-speed performance relative to other cars would require the CRB to disregard the SCCA
Power Factor formula and the BoP standard, which focuses on balancing performance at speeds where aerodynamic loads have
not yet begun to dominate acceleration rate — namely in the 60-100 mph range. Because aerodynamics can be changed on a
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chassis from track to track and, indeed, from session to session, balancing performance in higher speed ranges would result in
data that varies with the aerodynamic tune of a chassis. When the data varies, the primary performance measurement that the
CRB has successfully used in the performance-parity process loses its ability to make accurate comparisons between cars. The
BoP standard is used in P2 to equalize, as closely as possible, acceleration rate between 60 and 100 mph, and the current
restrictors provide that balance for cars in the P2 class, including for Spec Line Cars with engine sizes 1005 cc and less. In order to
make adjustments to the restrictor size and/or weight of a specific car/engine combination, the CRB needs to have on-track data
to be able to make accurate comparisons. If a competitor believes a particular car/engine combination is out of line with the
class BoP standard, it is incumbent upon the competitor to contact the CRB in advance of entering and competing in a U.S.
Majors Tour or Hoosier Super Tour event to allow the CRB an opportunity to gather the relevant data and make appropriate
adjustments if warranted.