RENNtech Carbon Fiber Bubble Top Airbox for V8 (M113 Engines)RENNtech Carbon Fiber Bubble Top Air Box for M113 Mercedes Engines Our full carbon fiber airbox is more than just an impressive under the hood showpiece. By allowing a greater volume of intake charge air; our carbon airbox upgrade allows for greater horsepower and torque across the entire RPM range. The result is an additional 10 HP and 10 Lb ft with increased throttle response and improved drivability. Note: This upgrade requires a core exchange for