89 Rx7 Gtu-s Rx7 on 2040-cars

Auto blog

Mazda engineer wants new rotary to be turbocharged

Hope springs eternal for Mazda to revive the high-revving Wankel engine for a new sports car, and the company keeps feeding that thirst with hints that it could happen. To make the possibility even more tantalizing, Mazda drivetrain and powertrain assistant manager Tetsushi Marutani tells Motoring that he wants the updated mill to pack a turbocharger. "Personally, I think that a rotary with some turbo or compressor would be good," Marutani said to Motoring. "Because a rotary, in my opinion, they require more [torque at] low speed, low down torque. So if we have some small compressor or turbo it would help." Mazda hasn't sold a rotary-powered model since the RX-8 and hasn't had a turbocharged one since the third-generation RX-7. However, the recent RX-Vision concept (above) at least hinted at a possible Wankel revival, and Mazda officials confirmed that its engineers continued to develop the engine since the RX-8's demise. The RX-Vision used a next-gen rotary called the Skyactiv-R, but Mazda didn't officially confirm any details about it. Rumors suggested the engine had a two-rotor layout with a total displacement of 1.6 liters. A two-stage electric turbo and hybrid powertrain would allegedly boost the total output of around 450 horsepower. The electric assistance could also counter the Wankel's lack of torque at low revs and poor fuel economy. Those rumored specs sound fantastic, but we still take the rotary's return with a grain of salt. Mazda CEO Masamichi Kogai is adamant that it's not worth the company's limited resources to develop a niche sports coupe instead of better selling vehicles. Related Video:

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.

2014 Mazda6 recalled due to fuel overfill fire risk

Mazda is recalling 19,000 Mazda6 sedans from model year 2014, over concerns that the fuel tanks can be filled up too much. What is it with Mazda and fuel tanks?
The big concern is, obviously, spillage when filling up. There's also a risk that a radical temperature swing could cause the fuel volume to expand, causing a full tank to spill over without the driver knowing about it. According to the National Highway Traffic Safety Administration bulletin, if the fuel spills over, it could end up in something called the charcoal canister, which helps with the car's emissions. If it fills up the canister, it could leak out onto the road. None of this is really desirable.
The affected vehicles were all built between October 25, 2012 and May 9, 2013. It's unclear if there have been any fires due to this problem. Dealers should have been notified by now, while owners should begin receiving official recall notifications very soon.