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Mazda files patents for a sequential twin-turbo setup

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. That's basically how the Mazda design shown above functions. A big flap blocks off the larger turbocharger exhaust inlet, channeling all the exhaust to the smaller turbo. When more exhaust is available at high rpm, it looks like that flap opens up to spool up the big turbo, too. What's interesting here is that the way the turbochargers are packaged takes up less space than past systems. It looks like both turbos are contained in one unit that shares the same exhaust outlet, meaning the exhaust manifold could be kept simple and compact. In fact, the piping for compressed intake air could also be shared, reducing the amount of piping, which would further decrease the amount of materials and possible failure points. There are a number advantages of making this system smaller. The potential applications of the system are much greater, since it could fit in smaller cars with smaller engine bays. Making the system smaller also means that there won't be as much weight, which is important from both fuel economy and performance standpoints. Finally, the smaller setup likely uses fewer materials, which could make the system cheaper and thus easier to offer on a wider range of vehicles, or at least more profitable for Mazda.

Autoblog Podcast #396

Episode #396 of the Autoblog Podcast is here, and this week, Dan Roth, Steven Ewing, and Chris Paukert talk about the 2016 Mazda MX-5 Miata, the 2016 Jaguar XE, and the 2015 Lexus RC. We start with what's in the garage and finish up with some of your questions, and for those of you who hung with us live on our UStream channel, thanks for taking the time. Check out the rundown below with times for topics, and you can follow along down below with our Q&A. Thanks for listening!
Autoblog Podcast #396:
Topics:

Bauer Catfish is a Miata-based trackstar in the making [w/videos]

We're not trying to make a joke here. The creation you see above really is called the Bauer Catfish, and while the name is about as attractive as your average bottom feeder, the car itself is built on a sexy notion. Take the mechanical bits of one 1990-2005 Mazda MX-5 Miata, add in a tube chassis for as little weight as possible, complete with some custom body work and go forth. Bauer says the finished product weighs in at just 1,550 pounds, and the company will be happy to pull the stock four-cylinder to drop in a healthy General Motors LS V8.
The pre-production prototype shown above competed in last year's 25 Hours of Thunderhill, finished the race and earned a spot on the podium in the "anything goes for sports racers" ESR class. Very cool.
If you're looking for a dedicated track car, it may not get any better than this for the money. Expect to pay around $13,900 depending on options, plus the cost of your donor Miata. That's a good sight cheaper than a used Chevy Corvette Z06 and likely to be quite a bit more fun. After you're done watching it in action in the brief videos below, check it out over at Bauer Ltd.