Fresh Air Exhaust sucks the exhaust out of the engine so there is no loss in engine performance. The following chart shows boat speed, with and without FAE. The typical boat loses one to two MPH of top end speed due to the small amount of drag from the part of the FAE in the water.
Also, fuel consumption is unchanged.
As the boat moves forward, the water flowing past FAE creates a venturi and the exhaust is literally Sucked out of the engine. The venturi suction reaches 50 mph. Watch the “FAE Sucks” video to see this demonstrated.
Boat engine manufacturers specify that the exhaust back pressure not exceed 2 psi as higher levels may impair engine performance. On typical boats FAE does not increase exhaust back pressure above 2 psi except at engine speeds above 3500 rpm. With FAE installed, the typical boat loses 1-1/2 to 2 mph of top end speed.
Our customers tell us that the boat’s wake is essentially unchanged for slalom, wakeboarding and wake surfing and that boat handling is also unchanged.
The FAE testing shown in the graphs and pictures above were performed on a 2001 Tige 20i with a Mercruiser 350 Mag engine, measured by GPS and electronic fuel monitor. This engine is typical though your results may vary.
There are about 1500 FAE installed, including several by boat manufacturers and there have been NO performance or warranty issues.