Madness Is Giving A Tiny Six-Horsepower ‘70s EV A 155 HP Motorcycle Engine

Hayabusa Swapped Ev Mini Citicar First Drive! 20 31 Screenshot Copy
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The CitiCar was an electric car from the era when EVs just weren’t very good. Built in the 1970s, it had dismal range, single-digit horsepower, and a top speed of 38 mph at best. Vasily of Vasily Builds decided to change all that when he gave the ancient cheese wedge the beating heart of a Suzuki Hayabusa.

The Hayabusa’s inline-4, 1,340cc engine is a popular swap for all kinds of tiny cars in need of more power. That’s because it packs serious horsepower into a package small enough to fit inside a motorcycle frame. In the case of this build, Vasily sourced an example with 155 horsepower. As a guide, that’s roughly 26 times as much as the most powerful CitiCars at the end of production (those beasts made six horsepower), or 62 times more than the initial models (a peppy 2.5 horses). Oh, and the engine has a stratospheric 11,500 RPM redline to boot.

Of course, dropping a Hayabusa engine into an ancient EV isn’t a straight swap. Vasily had to completely rework the chassis of the CitiCar and install everything necessary to support the new internal combustion drivetrain. As you might expect, it’s been a long-running series on Vasily’s channel, given the amount of work involved.

The basic idea was to mount the Hayabusa engine in the rear on a steel subframe hooked into the bulkhead of the CitiCar. Vasily started with an off-the-shelf subframe from Protolite Racing (below). Designed for adapting off-road buggy builds to motorcycle drivetrains, the setup includes a double H-arm suspension setup along with a special gearbox that accepts the bike’s chain drive and sends it to both rear wheels. The subframe was revised and tweaked multiple times until Vasily got it just right, and is tied into the original chassis along with a roll cage to add strength to the chassis overall.

2017 Suzuki Hayabusa
Suzuki
Screenshot 2024 03 14 At 8.53.48 am
Protolite Racing

Other work involved fitting a gas tank, Miata disc brakes, and a cooling system for the engine. Vasily also went to the trouble of installing custom front suspension to match the independent setup at the rear, choosing a double-wishbone design and coilovers in the hope of giving the CitiCar the handling to match its Hayabusa powerplant. It also got a trick new set of 13 x 8 wheels running Hoosier rubber.

Hayabusa Swapping My Tiny Electric Car Part 5! 0 1 Screenshot
The rear end at an earlier point in the build. 

As you might expect, the first drive wasn’t free of issues. The engine was down on power with two cylinders not firing, and the gearing wasn’t ideal, either. A bad bushing in the rear had suspension components rubbing on the wheel rim, and heat from the engine was radiating into the cabin.

With the most pressing of those problems fixed, it’s clear the once-gutless CitiCar has become a monster. The soaring roar from the superbike engine is matched by the rapid pace of the scenery flicking by the windows. Making a hard pull down a wet road, Vasily can be seen making rapid corrections to the steering wheel to keep the thing pointing in one direction—no surprise given the short wheelbase and the high power-to-weight ratio. The original CitiCar weighed just 1,300 pounds, and this one isn’t a whole lot heavier. “It’s all over the place!” he exclaims, as it squats hard under acceleration and with every rapid gear change.

It’s quick, but it’s also definitely the kind of vehicle you don’t want to crash. It’s so small inside that the crumple zones are whichever bits of your face hit the windshield. There are some compromises too, like the filler neck for the gas tank sitting under the driver’s seat. This tends to fill the cabin with fumes after refilling.

Hayabusa Swapped Ev Mini Citicar First Drive
Oversteer can be snappy thanks to the short wheelbase. It’s not a drifter.

You could go a completely different route to building a fast CitiCar today. With some battery modules and a motor out of a small EV, you could make it quick without all the hassle of internal combustion. And yet, it would somehow lack something compared to Vasily’s effort, which is clearly so much better for the screaming wail of the Hayabusa engine in the back.

All I’ll say is that this project is valid. And necessary. This CitiCar may not be tame. It may not be useful for anything. But it’s rad as hell and shouts like the dickens. Let’s have more of this sort of thing!

Image credits: Vasily Builds via YouTube screenshot

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33 thoughts on “Madness Is Giving A Tiny Six-Horsepower ‘70s EV A 155 HP Motorcycle Engine

  1. I laughed as soon as I saw the headline. I remember these cars because they were sold a few blocks from me when I was in 5th grade. They are made out of almost nothing. You’re not likely to survive a crash.

  2. Id love one of these engines swapped in my 1700lb Insight, but I dont wanna mess with chain drive and I dont know of a transmission with a clutch that can handle 12krpm and bolt up.

    1. K20 swap that shit. You won’t be disappointed. You’ll run 1/4 mile times somewhere in the 13s if you can get the tires to hook up, and when you drive it normally without stomping the accelerator all the time, you’ll get about 45-50 mpg.

        1. I’m curious as to its gear ratios. It would be a terrible waste if it only topped out at like 80-90 mph. With such a high-revving engine, fuel economy would be poor for what the car is. Its bad aero will certainly not help things.

          I’d totally paint this thing up like the red Makigaki Mai Mai from Cyberpunk 2077, and even give it a custom headlight and asymmetrical taillight job to look the part.

  3. Thank dog he included a roll cage. Something this small is more like a quad or Kart than a car. Hellacious fun on a track and a death trap on the road.

    1. Back in the early 90s a UK quad builder made a roadracing quad using a Krauser Grand Prix sidecar engine, which is even crazier. Also in the oughts a guy in New Zealand made a jumbo sized quad from a Subaru WRX drive train.

  4. When I first saw this I thought “So it’s just throwing a plastic body on a Legends racer.” It’s not, but that sounds like an easier and safer solution. I have a friend who owns a CitiCar himself…and he’s planning on a more sedate ICE conversion. I wonder if he’ll follow through once he sees this.

  5. Interesting that his channel popped up on my Youtube feed for the first time just last night for a video where he swapped a Yamaha Banshee inline twin 2-stroke engine into a KX250 dirtbike in 24 hours.

  6. With the modifications to the front end the anthropomorphic face looks like it is permanently frozen with the expression of what it must have felt like to have a motorcycle engine shoved where the battery don’t shine.

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