For owners of Dodge Rams who are looking for a big – and we mean big – upgrade over their B-series Cummins' stock Holset turbo unit, ATS brings this super-cool sequential turbo system to market. The first-stage turbo is the first to get the incoming air, while the second-stage turbo gets first dibs on the exhaust stream (this is because it has more work to do). The combination of two turbos in series provides the potential for serious boost levels – some diesel guys like to boost their engines into the triple-digit PSI levels – but of course this isn't cheap or simple. That just makes it all the more attractive to enthusiasts, right? You gotta love a turbo system that's adjustable down to 40 PSI. There's another picture after the jump.