Get Hotcars Premium. Start your free trial today

Will modified modern metal win against an original, track-tested AC Shelby 427 Cobra big block?

The Factory Five Roadster is the best-selling replica of the original AC Shelby 427 Cobra. Considering prices of original 427 Cobras are now sitting up around the million dollar mark, the Factory Five Roadster Mk 4 kit starting at around $15,000 is any enthusiast’s ticket to getting a taste of a Cobra. But just how good is the replica compared to the original?

That’s what Gunpowder & Gasoline, TV’s most popular firearms and automotive show now on YouTube, set out to find the answer to. The team has squared up a Factory Five Roadster with a Ford 5.0-liter Coyote V8, against the big, bad boy of muscle cars itself: a fully original AC Shelby 427 Cobra big-block. Of course, the Cobra’s got displacement on its side, all 7-liters of it! Before both cars are put to the test, the team decides to even out things, by adding a few parts to the Roadster to help balance the scales.

It's the age-old question of modern engineering vs classic muscle. Except, this time, the cars are practically the same, just separated by 45 years of development!

The Shelby 427 Cobra is no ordinary Snake though. It’s a whole other beast than the regular Cobra with a 4.3/4.7-liter V8. Only 300 (or 343 depending on who you ask) of the 427 Cobra were built in total, as they were originally meant for competition. Each with a 7-liter Ford V8 developed for NASCAR that made 410 HP, with the ultra-rare Competition models pushing that up to 485 HP, good for a 0-60 MPH time of around 4.2 seconds. If the rear tyres can hook up that is.

Related: Carroll Shelby Would Be Proud Of This New AC Cobra Concept

Prices are north of a million dollars, with a 427 Cobra recently being sold for over two million dollars! That puts it out of reach of most people, but the Factory Five Roadster is a great alternative for the enthusiast looking to get his hands dirty.

While the basic Factory Five Roadster kit starts at $15,000 without a drivetrain and running gear, if you’re looking at one as a project car, that leaves it wide open to choice. The Factory Five kits have been engineered to take on a wide variety of engines, brakes, suspension and more, depending on how much power you want. And your budget, of course. For $21,000 though, you could get a full kit, ready for the drivetrain, wheels and tyres of your choice.

This particular Factory Five Roadster is powered by a stock Ford 5.0-liter Coyote V8, the same motor that’s in everything from Ford pickups to the Ford Mustang. To give it a chance against the 427 Cobra, the team decides to give it some more firepower, and beef up the braking and suspension.

Related: Here's What You Should Know About Building A Factory Five Cobra

For starters, the standard rear axle is upgraded to a Moser Engineering rear end that can handle more power without twisting itself into candy. With the team planning to test the handling of both cars on a slalom course, the Roadster’s sstock suspension makes way for adjustable Koni coilovers. Wilwood ventilated brake rotors and six-piston brakes are then added to make sure the Roadster can stop on a dime as well. On the engine side, the stock intake is swapped out for a Ford Racing Boss 302 intake. A reflash to the engine control unit takes power from around 465 HP closer to 500 HP. All in the total build comes to around $40,000. Not bad at all, especially considering what comes next.

With all the upgrades to the suspension and brakes of the Factory Five Roadster, not to mention the newer, stickier rubber, the Roadster manages to be faster around the slalom course. Over a short course, the two second difference really highlights just how much of a difference modern suspension, brakes and tyres can make. On a full length racetrack, that difference will easily build to double digits. The Roadster, unsurprisingly, stops shorter too when braking from 60 MPH, but we expected that. The real question is how much quicker will it prove to be over a quarter mile compared to the big block NASCAR motor in the 427 Cobra?

Turns out the answer is just over 1.5 seconds. Even with a pro driver behind the wheel of the 427 Cobra, it manages a best quarter mile timing of 14.43 seconds. The modded Roadster on the other hand crossed the line in 12.86 seconds, with a closing speed of 114 MPH versus the Cobra’s 92 MPH.

Sure, the replica smoked the original in these tests, but we’re sure the outcome would be a lot closer if the two cars were on the same tyres. After all, no matter how much power a car has, or how good it handles, it all comes down to the contact patch that the tyres create. We can’t wait to see a rematch, this time with the 427 Cobra on modern rubber!

From playing with HotWheels to tracking his race toy, Sam's come a long way. A penchance for translating his automotive hijinks and geekery into the written word comes in handy every now and then...