Anti-lag really only works in operating modes where the driver doesn't request maximum torque. That is, during the shift or during part throttle. That's when there's an excess of air flow that can be burned with fuel to run the turbine.vwchuck wrote: ↑Wed May 16, 2018 9:25 amTo build boost out of the powerband you add fuel and retard the timing. Then the burn happens in the exhaust system and increases your back pressure to spin the turbo faster almost instantly. This is also know as the anti-lag system in most aftermarket EMS's..
When the driver is requesting maximum torque, there's no such obvious source of excess air. For every oxygen 2 molecule that is burned in the exhaust manifold, there's one less oxygen 2 molecule burned in the combustion chamber and thus less torque applied to the crankshaft. That's the issue I'm struggling with.
Since fuel can't burn without oxygen, just adding fuel to an already rich misture isn't going to cause more reaction. It can slow down the burn, but retarding ignition timing may be a more efficient way to slow down the burn? Or may not.
One logical reason why excess fuel might work is that it may efficiently use heat of the combustion to vaporize and expand, converting heat into pressure, thereby cause the turbine run like a steam engine. But I haven't worked out the physics of that.