The Fiat 124 Spider is the Mazda Miata’s oft-forgotten Italian sibling. Even though it shared a platform with the ND Miata, it had a different engine, an older transmission, and a quirkier design that never fully resonated with enthusiasts.
With only a few thousand units sold over a three-year production run, the 124 Spider was discontinued in 2019. That said, it did still have a bit of a cult following—it was essentially just an ND Miata underneath, after all.
One of those followers goes by @kynetic24 on Instagram. They have a custom-built 124 Spider track car that looks completely unhinged in the best possible way. It’s the car Fiat probably should have built from the beginning.
Photo by: @kynetic24 / Instagram
The track-prepped Spider wears a full hardtop conversion, a widebody kit, flared fenders, front and rear splitters, tow hooks, and a massive rear wing. But the real surprise is under the hood. We reached out to the owner to learn how this wild project came together.
“I think anyone who starts a track car project eventually falls down a rabbit hole of constant critique and never-ending refinement in pursuit of the ultimate track weapon,” they told Motor1 via email. “I loved how nimble and capable the platform was from the start—it just lacked high-end power.”
The owner admits that they chased the idea for years, with one of the biggest challenges being the lack of aftermarket support for the 124 Spider’s unique 1.4-liter engine in the US. From the factory, that motor produced just 160 horsepower.
When the aftermarket came up short, they landed on, frankly, a much better solution: a Honda K24 swap.
“I didn’t really explore other engine options,” the owner tells us. “The moment I learned a K24 swap was even remotely possible, I just went for it. The engine revs high, makes a ton of noise, is readily available, relatively inexpensive—and it’s a Honda.”
Naturally, the swap wasn’t as simple as dropping the engine in and calling it a day. They say the biggest hurdle was the extensive chassis work required to get the engine mounted low enough. “The steering rack, electronics, and just about everything else had to be reworked and re-engineered,” they explain.
The K24 is paired with 275-mm-wide track tires on 17-inch wheels, along with front and rear splitters and a large rear wing to generate some extra downforce. It also still uses the stock six-speed manual that came with the car when new, ripped from the NC Miata. With all the pieces in place, the transformation was dramatic.
‘The moment I learned a K24 swap was even remotely possible, I just went for it.’
“With the stock 1.4-liter setup, I was making roughly 140 wheel horsepower at 7,000 rpm and about 210 lb-ft of torque at 4,000 rpm,” the owner tells us. “That meant full torque was available the moment I exited a corner, but power dropped off sharply after 5,000 rpm. It made the car explosive out of corners and very competitive in tight, technical sections, but it didn’t have the legs for long straights.”
“With the K24 swap, the car now makes around 270 wheel horsepower at 8,000 rpm, with most of the power coming on above 6,000 rpm. With minor engine mods, I can rev it past 9,000 rpm. The vibrations, noise, and overall feedback are a sensory overload compared to the factory setup. It demands more skill to drive fast, and the feedback is dramatically amplified. I love it—and I’m looking forward to more proper testing.”
Photo by: @kynetic24 / Instagram
Even so, this owner isn’t done chasing lap times. While most of the major upgrades—engine, aerodynamics, wheels, and tires—are already complete, they say the final step will likely be a supercharger.
“Given the NC gearbox’s ability to handle higher power, and the smoother power delivery of a supercharged K24 compared to a turbo, the goal is a reliable, consistent track weapon that’s affordable to maintain.”
Although there’s no price tag on the build, they admit getting the car to this point was “not so affordable.” Still, there’s an upside: in a sea of modified Miatas, there probably aren’t many Fiat 124 Spiders showing up at your local track day—especially not ones that look like this.
