2009 Cx-7 Grand Touring 4dr Suv on 2040-cars

Auto blog

This is what a 1,200-hp twin-turbo 4-rotor looks like in a Miata

We've seen the diminutive Mazda MX-5 Miata swallow plenty of big engines, but New Zealand drifting ace "Mad Mike" Whiddett is roaring into where-no-man-has-gone-before territory. Wanting to replace his 515-horsepower "MADBUL" RX-7 and its twin-turbocharged, three-rotor 20B engine, his new ride is an NC-series Miata with four rotors and twin Garrett turbochargers courtesy of Pulse Performance Race Engineering. It is called "RADBUL," and expected power at standard boost is 1,200 hp, but the builders at Pulse Performance think it will get up to 1,500 hp at full boost. And yes, that exhaust exits through the hood. Four-rotor engines are actually popular - builds are detailed on forums like this one from 2007 and this one from 2008, this UK company or this Canadian company will sell you one complete - but they're usually being prepped for an RX-7. Mad Mike's choice of a Miata for this enterprise makes this about as extreme as you can get, short of throwing it into a Mazda R360. You can watch Mad Mike tell the story of the build in the video, and check out the first and second installments about the build on the Red Bull site.

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:

Patent application suggests Mazda rotary return

A recent patent application by Mazda reveals that the Japanese automaker is still working on the rotary engine. This could in fact be the Skyactiv-R engine found in the RX-Vision concept from the 2015 Tokyo Motor Show. As with anything Wankel-related, nothing is certain until Mazda makes a production commitment. But this filing suggests that serious development is happening in Hiroshima. The 2011 Mazda RX-8 was the last rotary-powered car you could buy in America. Slow sales, poor fuel economy, and tighter emissions standards prevented Mazda from committing to a follow-up. But the fundamental principles of the rotary - compact size and light weight - perfectly fit Mazda's Skyactiv ethos. (For an explanation of how rotaries work, click here.) In this new engine the intake port sits at the bottom of the engine with the exhaust port on top instead of the other way around. That allows for lower mounting, which improves a car's center of gravity. This rotary is also turbocharged. Putting the turbo up high helps ensure it doesn't get in the way of any body or chassis crossmembers. The implication of those claims is that somebody is thinking about how to put this engine in a car. There are other benefits as well. The short path from the exhaust port to the turbo ensures minimal turbo lag. It also allows for a close-mounted catalyst on top of the enigne, which will help emissions. Another innovation in this new engine is a triangle-shaped rotor that covers part of the exhaust port. This allows for different exhaust flow characteristics. The filing claims that that two of the four orientations allow for less airflow resistance in the exhaust port. As in previous Mazda rotaries, there are two spark plugs to manage ignition timing and combustion. But unlike in the 16X concept, Mazda's last public display of such an engine, the new rotary uses port fuel injection. Keep in mind this is only a patent application. A Mazda spokesperson refused to comment on future product, but commented "As we stated at the Tokyo motor show, Mazda is doing all that it can to bring a rotary to the market." In the meantime, keep your RX-7 prayer candles lit and hope for the return of the rotary before the end of the decade. You can bide your time by reading the entire application here. Related Video: Related Gallery Mazda RX-Vision Concept: Tokyo 2015 View 11 Photos News Source: USPTO via autoevolution Rumormill Mazda Performance rotary mazda rx7