Folks,
If you read the AMA rules book, and the rules as posted on the Brodak site, you should not have a problem with any of the events. The Nitro-muffler rule is a bit confusing, but under the AMA rules almost any muffler or tuned pipe may only use 10% fuel. Open face is unlimited, but Brodak has always asked for 10% as a local policy. Sportsman and 15 are not AMA events. I follow NCS recommend rules, but as unofficial events the rules can be different from one contest to the other. For example, I allow muffler pressure in the unofficial events. The AMA rules and most unofficial carrier events around the country do not allow muffler pressure in profile.
My goal is always to get people to fly and have fun.