This picture shows how the total exhaust measurement is made. The measurement is taken from the front of the header flange to the first weld on the expansion chamber of the pipe. Changes to the exhaust length are made by using different sizes of flexible steel pipe (referred to as “flex”) between the header and the actual pipe. A longer exhaust length gives you better bottom end power and a shorter length gives you more top end. Changing your exhaust length is akin to changing your gearing. The interplay between exhaust length and gearing is crucial, and adjusting your exhaust length can be helpful if you find yourself “between teeth” on your gearing. In general, for Senior, start at whatever minimum length is allowed by your rules. For Junior (where there are 3 different levels of restriction) you will use a longer flex the more restricted your header is. Recommended flex lengths can be found in the X30 Junior tuning page.

One of the many good things about the X30 is that, unlike some other motors, there is no performance difference between exhaust pipes. It’s nice knowing you don’t need to test multiple pipes in order to find something special. That said, new pipes make more power than used pipes. As pipes get used, they get gummed up with carbon and performance drops off. Your best bet is to have a practice pipe and a race pipe.