The all-new addition to the Turbosmart line-up is the fresh air ALV40 (Anti-Lag 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 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 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.
What is an Anti-Lag?
The concept of anti-lag is to reduce or eliminate turbocharger lag. Turbocharger lag is generally considered the time it takes for your engine to produce boost. Note, we say time – Not RPM. Anti-Lag is in an improvement in response, it will not make a large turbo create boost earlier in the RPM range on a dyno (as an example), but a well setup system will ensure you maintain boost between gear changes and dynamic (On / Off) throttle situations as seen in motorsports such as drifting, rallying and such.
How does Anti-Lag work?
There are a couple of Anti-Lag strategies based on your engine, vehicle and ECU. The Turbosmart ‘Fresh Air’ ALV40 is the basis of a full bypass system where the valve actually opens when the throttle is closed & allows compressed air from the turbocharger to be directed into the exhaust manifold prior to the turbocharger – effectively ‘around’ the engine. This compressed air requires an ECU strategy of additional fuel & adjusted ignition timing to effectively ignite and control a burn, in the manifold right before the turbo. This burn creates energy, which can maintain turbine speed, also known as boost.
Is this all I need to get going?
Not really. This valve is specifically designed to do this job, however in order to actuate the valve you will need to operate it via either boost or vacuum. Either of which will require a charge canister in order to hold the boost or vacuum, ready for use. Although there are many ways to do this (we recommend talking to your tuner, before you decide) a common way to activate the charge canister is via a check valve / system of some kind. Then, once your canister is charged you can use a 4-Port electronic solenoid to control the two sides of the ALV40 actuator.
Is this just an External Wastegate?
No. The Turbosmart GenV External wastage architecture did make this product a reality – However there is a small, but important difference between a wastegate and an ALV40: True Twin Port Control. The valve may be capable of handling exhaust gas temperatures, however in an Anti-Lag application you are actually passing much cooler, compressed air (rather than exhaust) As normal External wastegates do have exhaust gas which is much hotter, they run a relatively large tolerance on the valve guide. While this is a design feature and very necessary on an external wastegate, we can engineer in a much tighter seal on an Anti-Lag valve and this ensures much more accurate & higher levels of valve control.
Is this the same as throttle kick Anti-Lag?
Not at all, no. There are a couple of key differences and yes, you require more hardware to do it. Throttle Kick style Anti-Lag has been a feature on most aftermarket ECU’s for some time. Fresh Air Anti-Lag however has several distinct benefits. The first is significantly lower EGT’s during Anti-Lag operation and that means greater reliability of your turbocharger, manifold and accessories. The other benefit is around vacuum boosted brake systems. Vehicle’s fitted with these types of braking systems (most cars) will lose braking assist when kick-type Anti-Lag is activated as the engine does not run in vacuum. A Fresh Air Anti-Lag system however does have vacuum and maintains all vacuum bases & boosted accessories when in operation.