The Mazda MX-5 has never been synonymous with pure speed, but cram an LS7 V8 in there, and then the little roadster will become very fast. The owner of a fourth-generation Miata in the retractable hardtop Fastback specification documented its build on YouTube, culminating in a video shot on the highway with the RF at full tilt. While a standard car will do around 140 mph (225 km/h), this little beast managed to hit 187.4 mph (301.6 km/h).
If you’re wondering how powerful the eight-cylinder engine is, a dyno test from a year ago showed a colossal 514 hp and 675 Nm (498 lb-ft) of torque. That’s quite the bump over an ND1 or ND2 Miata, which comes in at no more than 181 hp and 151 lb-ft (205 Nm) for the facelifted version launched with the 2019MY.
Squeezing in a big V8 certainly added weight over the 2.0-liter four-cylinder engine while impacting the factory car’s ideal 50:50 distribution, but it still has to be a car incredibly light by today’s standards. Even in the slightly heavier RF flavor, the hardtop Miata weighs around 1,100 kg (2,452 lb for the US model) in stock form.
The first attempt to cross the 300 km/h mark did not go exactly as planned. As the pint-sized roadster zoomed towards top speed, the upper windscreen trim flew off at 178 mph (286 km/h). Let’s just say the little Mazda wasn’t built for that kind of speed. Since the analog speedometer only goes to 150 mph (240 km/h), a professional data logger (Racelogic VBOX Sport) had to be used to accurately measure vehicle speed.
According to the owner, his beefy Miata could have gone even faster because the “speed was steadily increasing”, but there just wasn’t enough straight road on the famous German autobahn. Even though it hit “only” 187.4 mph (301.6 km/h), it may be the fastest road-legal MX-5 in the world.
