Mazda has an undeniable history of developing quirky engines. They pioneered the Wankel rotary engine for road use, and are currently working on a compression-ignition-with-spark-plugs combo motor, and their latest exploit has two turbos, and a supercharger. Because torque, basically.
Mazda just filed a patent showing an engine in this layout, indicative that they’re still exploring weird engines for road use. Surprisingly, they’re not the only company to have done something like this; Volvo explored a similar triple-boost setup on a 2.0L four-cylinder a few years ago that ended up making a whopping 450hp. Interestingly, the patent application does appear to show either an I4 or I6 configuration in a rear-wheel drive application, so it’s possible that this engine could maybe, if we’re lucky, end up in a Miata someday.
The other noteworthy thing about this motor is that it doesn’t use a conventional belt-driven supercharger like most of these cars do; instead, it’s powered electrically, guaranteeing virtually no lag as the electric motor can spin it up much faster than a conventional mechanical link. The application notes that the supercharger would provide low end-torque while the turbochargers spin up, providing a similar effect to sequential turbos while still getting maximum power from both.
Mazda is yet again proving itself one of the most adventurous carmakers in this area, and certainly among non-supercar makers. Hopefully, we’ll see this in a car pretty soon, but it’s unlikely it’ll be before the HCCI unit makes it into production in 2019.