Turbocharged Honda Grom Drag Bike Has Eight Times More Power Than Its Stock Iteration

The specimen shown in these photos is a perfect example, and it certainly looks a lot cleaner than most. Not only does it punch well above its weight with things like NOS and turbo technology, but it can also turn plenty of heads with that mesmerizing livery and aggressive stance. As you might’ve guessed, this modded Grom wasn’t pieced together by some regular Joe in their backyard shed.

On the contrary, it hails from one of the most prolific custom bike specialists that Britan has to offer, the revered Guy “Skid” Willison of 5Four Motorcycles. He boasts decades of experience in his line of work and numerous appearances on British television, as part of the cast for shows like Find It, Fix It, Flog It and The Motorbike Show. In essence, this man lives and breathes motorcycles.

Zooming in on his Grom build, it came about as a collaboration with Honda for the fabled Wheels and Waves festival in France. Skid had a mere five weeks to get the bike ready for the event, but he didn’t let the pressing deadline result in any sort of corner-cutting. A helping hand came from one Jordan Bowen, a friend who’d been racing Groms on the drag strip for about 10 years.

With the Grom delivered to the 5Four HQ and all the design ideas sketched out on paper, Guy and Jordan wasted no time digging in. First things first, they fashioned a long swingarm using parts of the original module and plenty of reinforcements along the way. The structural work was just getting started, though, and the aforementioned item can hardly be called a swingarm nowadays.

That’s because the motorcycle’s rear suspension was taken out of the equation, replaced by a solid supporting rod for added stiffness. As the swingarm won’t be doing much swinging from now on, it became the perfect place to mount a pair of billet aluminum foot pegs. On their quest for purposeful weight reduction, the project’s authors went so far as to delete the rear brake.

At the front, all the factory running gear appears to have been retained, but Guy did lower the forks by about two inches (50 mm) in order to achieve the correct posture. With the chassis taken care of, the Brits turned their attention to the Grom’s unassuming single-cylinder engine. In stock form, the air-cooled 124cc thumper can spawn approximately 10 hp at 7,000 rpm.

This is far from what you would need to go fast in a quarter-mile sprint, of course, but our protagonists came up with the perfect solution to fix that. Skid and his accomplice installed a premium Garrett turbocharger to really spice things up, and all the associated plumbing was fabricated in-house out of titanium. As you would expect, the engine internals were beefed up to handle the additional grunt.

Also aided by a nitrous setup, the bike’s single is now capable of producing up to 85 ponies when pushed to its limit. That’s a colossal jump from the mill’s original power output, even if the resulting figure may not sound particularly impressive when taken out of context. The engine-related work is pretty wild, for sure, but our protagonists weren’t done with the transformation process just yet.

Their next port of call was the bodywork, removing all the stock bits aside from the fuel tank and front fender. Bespoke side covers and a snazzy front fairing were then thrown into the mix, along with a new handmade seat featuring black leather upholstery and diamond pattern stitching. The cockpit was stripped of its unessential bits and fitted with a new handlebar, but the factory dash is still in play.

For the icing on the cake, a wild color scheme was needed to really underline the specimen’s nature. As suggested by a representative at Honda, Skid teamed up with a custom shoe designer and influencer known as MattB, who’d previously worked with celebrities like Ariana Grande and Ed Sheeran. He’s the one who came up with the rad design for the splash graphics, which we honestly can’t seem to get enough of.

The paint job was ultimately carried out by Arnie over at Pro Kustom, another one of 5Four’s trusted collaborators. For visual continuity, the graphics make their way onto the seat upholstery in the coolest possible way. Now, Guy Willison might’ve been the one to orchestrate this breathtaking makeover, but it really was a team effort at the end of the day!