In the heart of Ghana, where passion for cars is slowly becoming a cultural expression, the 1StubbornF90 is now that has risen above the noise. Known widely by its terrifying street name “Bonsam Mpo Suro” (Even the Devil is Afraid), this is no ordinary BMW M5. It’s a brutally engineered, fire-breathing monster with the soul of a fighter jet and the grace of a luxury saloon. And at the helm of this madness is a scientist named Kojo, whose vision, determination, and bank account brought Ghana’s fastest sedan to life.
From the factory, the F90 M5 comes with a formidable 600 horsepower and 750NM of torque. But Kojo was never one for stock settings. Today, this beast boasts a conservative tune good for up to 1400hp and 1200NM, and it’s not just talk; the platform is proven, and the parts list reads like a motorsport fantasy catalog. Sleeved Cylinders allow for higher boost and durability. Forged Pistons & Rods for extreme combustion strength. A Micro-Polished Crankshaft for smoother, more efficient revving. A Billet Intake Manifold with Port Injection, adding fueling capacity and strength.
Methanol Injection, the first mod ever used to lower combustion temps and prevent timing pull, especially under Ghana’s harsh weather. Hybrid Turbos are built for rapid spool and insane top-end power. Custom Spool HPFP & Injectors ensuring fuel delivery matches power output. 2x OEM LPFPs for a stable low-pressure fuel supply. A Custom Exhaust engineered for max flow and sound.
This setup was painstakingly researched and wasn’t slapped on overnight. It took test after test, datalog after datalog, each run contributing valuable feedback which was sent to RK Autowerks in Texas. To ensure the build’s integrity, Kojo flew the entire engine out to RK Autowerks in Texas. This wasn’t just some local tune and slap-on job, this was a scientific rebuild, literally. The engine was boxed, flown overseas, torn down, rebuilt, reinforced, and tuned with precision. The cost? North of $35,000 – $45,000 for the engine build and tune alone when factoring in forged internals, sleeving, port injection, hybrid turbos, and custom tuning solutions (including remote datalog reviews post-installation). And that doesn’t include the countless hours of shipping logistics, taxes, and the heartache of fitting the beast back in Ghana
It doesn’t stop with the engine. The drivetrain was completely forged and rebuilt by Pure Drivetrain Solutions in the U.S., known for their bulletproof builds. A Rebuilt Gearbox. Upgraded Clutches. A Carbon Fiber Driveshaft. Everything in the drivetrain has been beefed up and it had to be, to handle four-digit horsepower reliably. In total, the drivetrain upgrades alone likely cost $20,000 – $25,000, bringing the powertrain cost close to $70,000.
Surprisingly, the suspension and chassis are stock, showing just how overbuilt BMW’s platform is. Yet handling is aided by a Cortex Electronic Boost Controller (EBC), allowing Kojo to manipulate boost levels with precision. Inside, carbon Sparco racing seats are waiting to be fitted, while outside, carbon fiber elements subtly hint at the monster underneath.
This isn’t just a garage queen. 1StubbornF90 has been on Ghana’s streets, in some of the most legendary banter races, none more iconic than the 911 Turbo S from Team Sub 10-Tials an all-time favorite showdown. And now, a brewing face-off with the Green McLaren 720S, also known as “Green Lantern.” These aren’t just races, they’re spectacles. The F90, a full-size family saloon, calling out aerodynamic hypercars built purely for speed? That alone tells you how much sauce Big Blue has.
Adding everything together engine, turbos, meth injection, manifold, fuel system, drivetrain, shipping, tuning, electronics we’re talking about a conservative total of $90,000 – $100,000 spent over several years this is nothing but sheer commitment and dedication. And let’s not forget, this build didn’t happen overnight. It’s been a step-by-step journey, a gradual process of constantly coming back to the drawing board as well as requiring relentless effort, continuous research, and immense passion. Kojo didn’t just build a car. He built a symbol. A symbol that West Africa can go toe-to-toe with the world’s best. A symbol that you can build, not just buy, greatness. A symbol that hard work, discipline, and the right mindset can put you ahead literally and figuratively. Young Ghanaian enthusiasts now look at 1StubbornF90 not just as a car, but as a movement and a peak of something great. One that says: “If you want it bad enough, you’ll build it, break it, fix it, and run it again.”
It wasn’t all done at once. Each stage was planned, tested, and re-evaluated. Data logs & parts went back and forth, but the end goal was always the same: build something that no one can forget.
Kojo has lit a fire under Ghanaian car culture. With his discipline, passion, and visionary mindset, he has given birth to a monster that now stands as a beacon of possibility. 1StubbornF90 is living proof that when you match desire with dedication, anything is possible. So the next time you hear the high-pitched scream of turbos spooling in Accra during the wee hours of the AMs, just know it might not be the devil. It might be what the devil’s running from.
