I just ran my exaust right out the side. I could have put the engine inverted, but I like to show off the Saito. The engine looks as great as the Plane in my opinion, and I didn't want to cover it all up. I hated to cut on the nice cowl, but I was pleased with the final result. Also I can easily get to the exaust without removing the cowl if it was to come loose. I used a silicone exaust extension on mine to help get the exuast away from the Plane which is not shown in the photo.