Section 3 — Muffler and Sound Reduction Devices

A. Only the 14 inch Flowmaster (part #53545-10) and the Schoenfeld (part # 14272735-78) mufflers will be permitted unless otherwise notified in writing prior to any event and subject to rule 15.3-B. The specified mufflers must remain unaltered from the manufacturer.
B. Several tracks have a locally enforced decibel rule, which preempt any particular muffler rule. In those instances the rules may be enforced by local government agencies. Track restriction decibel rules preempt utilizing the required mufflers in sub-section 15.3.A.
C. Titanium, carbon fiber and/or any other type of exotic material mufflers will not be permitted.
D. All mufflers must be securely mounted. Mufflers that are mounted with pop rivets and/or sheet metal screws will not be permitted.
E. Any muffler changes after the car has been through inspection will not be permitted. Mufflers used in qualifying must be used through the entire racing program. The only changes that will be permitted will be at the discretion of the World of Outlaws NOS Energy Drink Sprint Cars Series Director. Physical damage from a crash and/or other incident will permit a change, but then the car must be inspected again.
F. The mufflers must remain attached to the headers at all times. All muffler and header components must remain intact and operating. If the muffler becomes disconnected from the header and/or failures to operate it could result in disqualification from that race. If the muffler and/or header is damaged from and/or altered from track debris, a crash and/or a physical defect and/or no muffler components were lost and/or missing the penalty will be at the discretion of the World of Outlaws NOS Energy Drink Sprint Cars Series Officials.
G. Any muffler and/or header that has been altered in an attempt to gain a competitive advantage will not be permitted into competition and could result in disqualification.
H. All muffler rules and/or decibel (DBA) constraints are subject to state and local regulations as well as monitoring. World of Outlaws Series Sprint Car Officials will aid in enforcing the rules and regulations of those agencies.
I. When qualifying, any car determined to be in excess of the Decibel limit(s) set by either the track and/or any local agency, will receive only one (1) lap of qualifying at the end of time trials and the highest qualifying position the car may achieve is 50% plus one (1) of the field (50%+1).  If the car pulls off and no time is recorded, the car will be permitted one (1) lap at the end of time trials. If during that attempt the car remains louder than the limit it will result in an automatic disqualification.

2022 World of Outlaws NOS Energy Drink Sprint Car Series Muffler Rules