A project like the one that brought us here will raise lots of questions. And here’s the best one: why wouldn’t you put a rotary engine into a trike? Wankel motors are amazingly small for their output and deliver the kind of soundtrack that can crash any car meet. Well, as far as this machine is concerned, the avid builders over at Grind Hard Plumbing have been doing what their label says (minus the plumbing) for the past 18 months or so. And their RX-7 rotary drift trike is now complete!
The backbone of the contraption is a custom tubular frame, but, if that’s not already obvious by now, we’re more interested in its motivation. How much horsepower does the rotary drift trike make? We’ll get there soon.
With one less wheel, no body to support, and a single seat (among others), this machine is obviously much lighter than the already scale-friendly Mazda RX-7 that the iconic 13B twin-rotor engine is used to power—hey, another YouTuber put a 13B in a boat!
As such, the 1.3L Wankel is present here in naturally aspirated form, with a carburetor, which means you can expect anywhere between 100 and 200 horsepower.
The actual number depends not just on the configuration, but also the state of the engine—truth be told, Wankels are not without their drawbacks. And while the high emissions or oil consumption that forced Mazda to retire the motor a decade ago don’t matter here, the state of the Apex seals that ensure the hardware delivers proper power does.
Regardless, the 13B sends its power to the rear wheels of the trike via the factory Mazda manual, whose central, between-the-rider’s-legs position makes us think of a tractor (perhaps this Lamborghini 2241R?).
The Mazda RX-7-powered trike is a collection of parts
As Edwin Olding, who runs Grind Hard Plumbing Co together with Ethan Schlussler, explains, this drift trike is a collection of parts.
For one, the fork comes from a Honda motorcycle, while the rear suspension and differential were borrowed from an Audi A6. However, since this is a slip angle machine, the diff was diligently welded by Olding.
For the final phase of the build, the guys painted the trike, giving it a bit of an Iron Man suit look with the red chassis and gold gearbox—we never pegged Robert Downey Jr’s Tony Stark character for a rotary guy. But perhaps an RX-7 would be a nice addition to his supercar garage that’s been mostly represented by an Audi R8 and a second-gen Acura NSX.
It might be used for towing, too
With the contraption now finished, you can take a closer look at its details in the first video below—the boys promise to put the vehicle to sideways work for their next clip.
Meanwhile, though, we’ve added a second vid from one year ago, which shows a less complete iteration of the trike doing its drifting thing in the dirt, as you’d expect with those 15-inch off-road-ready rear tires. And yes, we too wish this thing would destroy some street tires, as drifting is (mostly) an asphalt discipline…
Now, as we mentioned when discussing the micro jet boat build you’ll see in the background of the first clip, Gring Hard Plumbing is the type of YouTube channel that engaged with its audience. As such, fans took to the comments section of the vid to suggest some drift trike tweaks of their own.
These range from a pair of rods replacing the tricky-looking steering cables and a fork split accommodating a larger front wheel, to lights that would help make this build street-legal and a tow hitch. And the builders already seem to have agreed to that last bit!