The Turbosmart ALV40 (Anti-Lag Valve) is a fresh air anti-lag bypass valve for motorsport applications. Featuring a 40mm valve diameter and a purpose-designed actuator housing. Multiple fittings are also supplied for ease of fitment and fabrication. The ALV40 Fresh Air Valve allows for incoming charged fresh air from the turbo to be diverted safely into the exhaust manifold pre-turbine wheel with the throttle at low opening angles to allow for safer spooling of the turbocharger without the potentially damaging throttle-based late combustion event style anti-lag that can induce high engine stresses and break connecting rods. The ALV is a sealed twin-chamber design, with the top port being the primary control port. The spring is designed to open under vacuum conditions to allow the air to bypass into the exhaust manifold, the lower chamber for twin-port control methods, control the valve irrespective of manifold pressure, and the shaft seal allows for leakproof operation. Features Twin Chamber Control Suitable for Boost or Vacuum Clockable Actuator Housing Optional 1-5 port outlet flanges Nitronic 60 Valve Guide and; High Temp 347 Ss Body 17/7 PH Stainless Steel Springs Strap Type V-band clamps