Rally Racing Anti-Lag is different from tradiitional misfire anti-lag in that it keeps your turbo spooled up while your foot is off this throttle.  Turbosmart's fresh air ALV40 (Anti-Lag Valve) is designed for motorsport applications, featuring a 40mm valve diameter and a purpose designed actuator housing.  The 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.  This allows 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 very hard on connecting rods and valves.  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 for the air to bypass into the exhaust manifold, the lower chamber for twin port control methods, to control the valve irrespective of manifold pressure and shaft seal allows for leak proof operation.  Multiple fittings are also supplied for ease of fitment and fabrication.