If you've watched any form of drag racing where turbochargers are involved, you've heard talk of two different types of engine equipment: two-step rev limiters, and anti-lag. Both are responsible for some massive exhaust flames erupting from a car that's revving at the starting line. But what's the difference between the two? How do they work? And what do they do to help your racing launch and drag strip ET? As always, Jason Fenske of YouTube's Engineering Explained is here to demystify the technology that helps racers win. With his trusty whiteboard illustrations, Fenske helps us understand the difference between a two-step rev limiter, anti-lag, and the launch control systems that some manufacturers now include from the factory on their high-performance cars. Basically, it all boils down to ignition control. An aftermarket two-step rev limiter lets you set one (lower) limiter for launch, and a higher limit for when you're upshifting as you accelerate awa...