Mazda has a history of interesting engine technologies, from yesterday's rotary engine to tomorrow's compression ignition engine, and new patents show it still may have some internal combustion tricks up its sleeve. The one on display in these patents isn't especially new in concept, though. A sequential twin-turbocharger setup is something Mazda itself used on the third-generation RX-7. But it's something we haven't seen much of lately. It looks like it could have some possible advantages over older sequential systems, and it has some potential advantages for enthusiasts.
First a quick and dirty primer for what makes a sequential twin-turbo system distinct from other twin-turbo systems. In many twin-turbo engines, there are simply two turbos that work together as one bigger turbo. They're the same size, and they spool up at the same time. With a sequential setup, at low rpm, a smaller turbocharger is spooled up first at low-rpm for quicker throttle response, and as the rpm and exhaust pressure increases, a valve opens up that allows a larger turbocharger to also spool up and provide high-rpm boost.
Rounding out a series of announcements today is the Macro Twin-Lite MT-26EX-RT, a dual Speedlite rig for macro photographers. The detachable twin lights can be rotated 60 degrees and provide a maximum guide number of 26m at ISO 100 (the existing MT-24EX is rated to 22m). It supports Canon's radio-based wireless control system in addition to the traditional optical setup. Flash power can be adjusted all the way down to 1/512 and recycle times range from 3.3 seconds in "quick" mode to 5 sec for a full recharge.
The Canon Macro Twin-Lite MT-26EX-RT Flash will be available in November for $990.
Mazda has already announced plans for an efficient Homogeneous Charge Compression Ignition (HCCI) engine but a new patent application suggests the company could also be working on something far more interesting.
Unearthed by Road and Track, the patent application covers a high-tech engine that uses an electric supercharger and two turbochargers. The supercharger would be used to provide low-end power while the exhaust driven turbochargers are being spooled up.
Practical Motoring has more on the rumored twin-turbo 4.0L V8 engine that could power the next-generation of Lexus F models:
…an anonymous source with knowledge of the upcoming North American Lexus LS model range confirmed to [Practical Motoring] that Lexus will be introducing a 4.0-litre twin-turbocharged petrol V8 engine. The source also claims there is ‘a good chance' that same engine will be placed into an LC F and, it would only be logical, that it will also be placed into the upcoming GS F.