CONCORD, NC-  Please note the following clarification and/or changes to rule 618.6: 618.6   PRESSURE / VACUUM TESTING

Testing may be performed to insure extra air is not being pulled into the engine for a performance gain. Any means to bypass the intent of the class rules is illegal.  Both pressure and vacuum tests may be performed -- engine must hold 5 psi for 60 seconds and/or 5 HG of vacuum for 60 seconds.