ok searched and didn't find anything realy pertanant, when you upgrade your exhaust do you runn richer than stock or leaner? i am pretty sure on a piston engine you runn leaner but a rotarty is seldom like a piston engine. going to get my cat back done soon and don't want to run to lean since my timing's advanced...
any help would be appreciated

james

 

Leaner - same as a piston engine.&nbsp The engine is still an air pump.&nbsp The more efficient you make the engine and free up flow, the faster it'll ingest air.



-Ted

 

the cat back alone won't make much difference. it also won't add much power though.