This Slow 2005 Ford Mustang Is Now A Beast That Slays Modern Muscle Cars

A humble 2005 Ford Mustang receives multiple modifications to the engine, making it among the most powerful custom muscle cars.

In 2004, Ford unveiled its 5th-generation Ford Mustang which was inspired by the original. The circular headlight clusters, and those crisp lines, gave its classic muscle car look, but the 5-spoke wheels were new. Elevating this Stang's appeal even further we have a cool modified custom. Built by a very ambitious person, the 2005 Mustang GT was meticulously upgraded to pump out 400 hp. While the power bump is modest, the journey is very inspiring.

The GT model was powered by a 4.6-liter V8 that made 300 hp, making it among the most powerful American cars one could buy back in 2005. It had the competition sit up and take notice, which is why Dodge followed with the Challenger in 2008, and Chevy with the Camaro in 2010.

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He goes by the name of Four Eyes on social media. He couldn't afford to buy one back in college, so he would constantly modify the Ford Mustang on the Forza game.

Many years later, he bought one. But by this time, modern muscle cars were way ahead of the game, making anything over 400hp. This meant the 2005 Ford Mustang simply did not have the bite to match the bark. After the purchase, the goal was to make it as good as the latest-gen Ford Mustang.

The first of many upgrades this Ford Mustang gets is a cold air intake, a pipe bomb axle-back, and a Bama tune. However, these were basic modifications that let the Mustang push out 292hp and 307 lb-ft of torque.

The stage 2 upgrade included a full exhaust system from Cooks. It included long tube headers, high-flow cat-backs, and an X pipe. He also added a new intake manifold with shorter Runners from Ford Performance, a bigger throttle body, an under-drive pulley, upgraded coils, and a lighter one-piece aluminum drive shaft.

All these modifications, along with a dyno tune, meant the Mustang was now making 327hp and 339 lb-ft of torque. That was a 12% increase over the stage 1 modification he carried out earlier.

Stage 3 included exterior upgrades, like a California Special bumper, a modified GT500 front splitter, and side splitters as well. He also customized aftermarket headlights, had the ducktail spoiler fixed on, and the deck lid shaved, giving it a tidy look from the rear.

The exterior now begins to look great. However, he also added a set of Detroit rocker camshafts. After another dyno tune, his Ford Mustang was now producing 363hp, putting it bang in the outgoing Ford Mustang's territory.

While he could've stopped right there, he chose not to by squeezing 400hp out of his car before boosting it. He knew the engine had to be rebuilt with stronger parts because the old engine will not be able to handle anything over 500hp. So he bought a forged stroker kit from MMR; this included a 3.8-inch stroker crankshaft, h-beams, and dished aluminum pistons.

Such internals can easily stand over 1000 hp, eventually pushing his Mustang's displacement to 4.9 liters. He also bought a pair of ported cylinder heads from Livernois that improved airflow compared to the stock heads. Stainless steel valves and stiffer springs were added too.

He also purchased cams from off the shelf for three-valve Mustangs. Plus, he ordered a full return style fuel system from On3 performance, along with 1000cc injectors. Street to Sand carried out the rebuild for him, and $9000 later, the owner had his car back home.

He fires up the Mustang; it rumbles louder than ever. A few hundred miles later, the custom-built Ford Mustang could manage to make 387hp and 353 lb-ft of torque. The goal was to reach 400hp, but he realized that it takes a custom-built engine a while to reach its maximum potential.

However, he couldn't wait any longer to put his custom-built muscle car against more modern rivals. So it starts with a full bolt-on LSD Chevy Camaro that made close to 450hp at the time of the race. The Camaro won the race, but the Mustang didn't do a bad job in the first and second gears.

The owner quickly realized that the gearing was too long on his Mustang, plus getting the 5-speed manual to shift into second gear turned out to show signs that the gearbox was already giving up its ghost.

So to replace it, he ordered a new, Tremec T-56 Magnum XL 6-speed manual transmission. A gearbox like this can easily handle over 1000hp and 700 lb-ft of torque. This transmission was also used in the Shelby Mustang GT500 and the 5th-generation Dodge Viper. He paired the Magnum gearbox with a twin-disc clutch and shorter 410 axle gears to improve acceleration.

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He went back to Street to Sand and requested them to squeeze the maximum power out of the engine, and the result was 408hp and 363 lb-ft of torque.

The first car he races is a 2001 Chevy Corvette, followed by a 2014 Ford Mustang GT, a 2015 Chevy Camaro SS 1LE, a latest-gen Ford Mustang Bullit, and a Dodge Viper GTS. The custom-built Mustang left all the cars behind, except the Viper because of its massive torque and aerodynamic shape.

Source: Four Eyes\YouTube

Rehan got published for the first time at the age of 17, having written a feature on a Triumph Herald in print. He uses his writing as a tool to express his fondness for all things automotive even today, aged 29. Collecting scale models is a hobby close to his heart, and he wishes to sprinkle pixie dust on them only to see them grow into full-sized cars. He now represents HotCars.com.