The little Smart Fortwo doesn’t have the best reputation here in America. Many people thought the car was just too slow and fuel efficient enough. One man spent a year building what is arguably America’s coolest Smart. This 2008 Smart Fortwo has the heart of a Suzuki Hayabusa and its performance will scare even the most fearless daredevils.

This Smart Fortwo is currently listed on Facebook Marketplace in one of those ads where the seller doesn’t give an exact price. It’s annoying, but the car in the ad caught my attention immediately. I know that car!

This car was purchased new in 2008 and in 2009 Michigan-based builder Matt Boesch transformed the little car into an absolute monster. It was also meant to boost an entire business, but then life got in the way. That might never have happened, but this car did it, and you can enjoy its incredible sub-5 second acceleration time to 60 mph if you dare.

The Build

I don’t have to tell our readers that Smarts are not exactly known for their speed.

The Smart Fortwo officially landed in the US in 2008. Distribution was handled by Penske Automotive Group, which made some unfortunate decisions to streamline and cut costs with its new Smart USA. In Europe, Smart built faster tuned Brabus cars and more fuel-efficient diesel cars. Smart Fortwo Brabus cars were known for their oomph, while the diesels got an honest 70 mpg in normal driving.

Unfortunately, Smart USA chose to give us a powertrain that is neither particularly fast nor particularly fuel-efficient. The company’s “one size fits all” solution was to give us a 999cc Mitsubishi three-cylinder naturally aspirated engine with 70 horsepower and 90 lb-ft of torque. Frankly, this engine is fine. These engines are known for their durability—better than the old Mercedes Suprex engines used to be in Smarts—and they can get over 40 mpg with a good driver behind the wheel. The EPA rated the Smart Fortwo at 41 mpg on the highway, which was the highest rating a vehicle without a diesel engine or hybrid system could get at the time. And as for performance? A 2008 Smart Fortwo could accelerate to 60 mph in 11 or 12 seconds, depending on conditions.

Unfortunately, Smart USA misjudged the market. While people in New York City, Chicago, and San Francisco found Smarts attractive for their ability to park anywhere, everyone else expected a little better gas mileage or at least more speed. But for most of Smart USA’s time, we got neither.

Some people have taken matters into their own hands and imported Fortwo diesel engines from Canada. I have one of these cars!

Those who were less concerned about fuel economy and wanted more speed quickly developed a whole world of tuning for these cars. Before long, manufacturers and tuners started selling turbo kits, ECU tunes, bolt-on performance parts and more. It seemed like almost everyone had a Doug Thorley exhaust, a Sprint Booster pedal remapping remixer and a cold air intake, while more daring people were installing metal slugs in their engine bays.

One of those manufacturers was Matt Boesch, who ran a small tuning shop called Genius Parts. Boesch brought years of experience from restoration shops and building race cars to the Smart world. For years, Boesch’s parts, including hand-crafted metal mirrors, shift paddles, armrests, and exhausts, were considered some of the best modifications in the Smart world. My own cars have had parts welded together by Boesch.

In 2009, Boesch decided to take on an ambitious project. One of the ultimate conversions in the global Smart world is swapping the motorcycle engine. Putting the engine from a liter bike in the back of a Smart made the car far more badass than any turbo kit ever could. There are plenty of videos of “Smartukis” and Smart Hayabusas doing all kinds of drifts, donuts and straight-line drags.

Boesch and his friend Nick from Troy Laser were obsessed with the desire to have their own Smart Hayabusa and started the SmartBusa project in March of that year.

The project began with gathering parts. They had a new 2008 Smart Fortwo on hand, then grabbed the 1298cc inline-four from a 2005 Suzuki GSX1300R Hayabusa. Stock, this engine produced 175 hp and 102 lb-ft of torque, about 2.5 times the power of a Smart, and that’s without any additional tuning. This engine cost $2,700 on eBay, complete with just 5,000 miles on the clock and an intact wiring harness.

Boesch wanted to offer this conversion as a turnkey solution to future customers, so his priority was to make the car suitable for everyday use. This meant adding reverse to the car. To do this, Boesch grabbed a Powertec/Quaife differential for $3,200. This differential not only gives the car reverse, but is also a limited-slip differential. One odd quirk of using this differential is that the driver could put the vehicle in reverse and drive through any gear that would otherwise be forward, which I would not recommend.

Boesch started by removing the factory engine and transmission from the Smart. From there, Boesch went in a different direction than most conversions. If you look at most Smart Hayabusa conversions online, they tend to have wide bodies, wide wheels, custom subframes, and other expensive custom features. Boesch figured he could use as much of the original vehicle as possible to keep costs down for this potential turnkey conversion deal.

His build would use the original subframe, wheels, brakes and suspension, but have a custom frame for the motorcycle engine that bolts into the original subframe. Boesch eventually figured out that he would have to make custom engine mounts as well, but he was able to reuse so much of the factory structure that the Suzuki engine would even use one of the factory engine mounts. Getting back to the whole everyday car part, Boesch even thought about NVH and the engine has rubber isolators so it doesn’t rip out your fills with vibration.

I’ll get ahead of myself here and note that Boesch gave the vehicle a stainless steel exhaust, a custom throttle and clutch pedal arrangement and decided to build a soundproof box for the motorcycle engine. On August 11, 2009, all the crazy work paid off and the SmartBusa started and ran for the first time. The project wasn’t finished yet, but Boesch proved it was more than possible!

He even announced pricing for a turnkey kit. For $17,500, you get everything you need to convert your Smart to Hayabusa power. Add another $1,000 plus shipping and Boesch said he would install it for you.

Unfortunately, in February 2010, almost a year after the project began, Boesch had to put the brakes on. The car ran, drove, and was insanely fast, but the owner of the vehicle gave up. Boesch was convinced that he had built the fastest Smart in America, with an acceleration time to 60 mph of perhaps only 4.2 seconds and a top speed limited by the gear ratio of 125 mph. He even achieved the goal of keeping the car somewhat usable on a daily basis, with a functioning heater and intact electronics.

Finally, the car lost several hundred pounds thanks to the motorcycle engine, which is significantly lighter than the old Mitsubishi hulk, and the Getrag transmission. Unfortunately, that meant the rear was high. Combine that with the incredible power, standard track and standard tires, and you get a particularly nimble Smart. Boesch reported that the car felt like it wanted to swap ends under hard acceleration:

(I)t is quite unstable and even a little scary when accelerating and at high speeds. What I will strongly recommend to the owner of this car and also future builds is a heavy duty suspension and wider wheels and tires. These things are needed to keep up with the extra power.

This was the end of the whole project. The car was gone and Boesch had the unexpected surprise of an imminent wedding ahead of him. Unfortunately, he had to give up the idea of ​​converting Smarts into Hayabusas.

The car today

Since then, Boesch’s SmartBusa has remained in the wild. Nick eventually sold the vehicle and it seems to me that it comes up for sale every few years. The car is hard to miss because of its SmartBusa badge and the huge insulated box with an engine in the back.

A year later I saw it for sale in Michigan for about $6,000 and I should have bought it then. I mean, Boesch spent almost that much on parts alone, not including the labor to put it all together. But I missed that then.

This time it’s for sale in the far east of Vincentown, New Jersey. The current owner doesn’t seem to be from the Smart world, but the SmartBusa looks just as good today as it did back in 2010. Unfortunately, it’s not as cheap this time. The seller says he wants “around $150” for it, but then offers a list of trade-ins that include Porsches, Polaris Slingshots, Nissan Skylines, and other vehicles worth far more than “around $150.” So who knows what this car will actually bring home.

The seller says the vehicle comes with upgraded wheels and tires to keep the performance somewhat up to scratch. The wheels here are Genius Darwins, which are actually just rebadged TSWs. These wheels aren’t as wide, so I would expect the previous stability issues to be present. This lack of stability is also probably why this car has had what seems like a billion owners since it was completed.

Boesch is still doing what he loves most. His shop is now called B2 Fabrication and he does everything from custom exhaust systems to overland conversions of the Porsche 911. Boesch’s conversions were even such a big deal the New York Times wrote about her.

Still, this is probably the coolest Smart in America. Although the lack of a wide body apparently makes this car intimidating to drive, I love that it’s an absolute sleeper. If you saw it on the street, you’d probably mistake it for another Smart. Then the crazy owner could open it up and outrun some real sports cars, as long as they keep the blue side up anyway.