My mechanic said that black smoke on boost is completely normal even with aftermarket ecu and tune, is this right? Sounds way off to be. Sure it's common because people don't tune their cars but from my understanding if you're popping flames or blowing a lot of black smoke, you're running way to rich? He was saying actually that you want to run very rich when boosting. Though a tuner told me you shouldn't have black smoke on acceleration only on deceleration. My spark plugs only last a few thousand km I noticed before my car started running rough, but now runs fine when putting new plugs in.
Most cars that I've seen boost hard have never had black smoke on acceleration.