The new 5.0 liter engine from Ford is proving to be a hot commodity among aftermarket shops. By itself the engine makes 412 horsepower and 390 ft-lbs of torque. Let a bunch of aftermarket specialists at it and you better be prepared for some seriously impressive torque numbers. And the engine is surprising even the most optimistic engineers.

Fastlane, who we told you about a few weeks ago, has gotten their turbocharged 2011 5.0 Mustang on the dyno. Get ready for this; it made 543 horsepower and 521 ft-lbs of torque at the wheels, on just 6 psi. This is an otherwise stock engine!

Fastlane was able to get its hands on one of the first 2011 5.0 Mustangs, and they have been hard at work since day one. “We’ve been working night and day like fiends,” says Nick Field, a dyno tuner over at Fastlane. When we first reported on Fastlane’s turbo, they were thinking they might make 530 horsepower at the wheels through their turbo system. We can only imagine their surprise when the numbers came out to 543 horsepower at the wheels. That is through a six-speed automatic transmission (which they put in 3^rd gear) and a stock rear end.

Why just 6 psi you ask? Well the new 5.0 has a very high compression of 11.0:1. Forced induction is a fan of low compression engines (usually around 9.0:1 or even lower) which allows the engine to run higher psi. For an otherwise stock engine though, those are some great numbers. Fastlane makes a similar kit for the 2010 Camaro, which through an automatic transmission makes around 530 whp. That 5.0 looks better and better every day.

Since posting that first video though, Fastlane has upped the boost to 10 psi. The result was around 600 horsepower at the wheels and similar torque numbers. “We’ve learned to vent the pressure through the engine, letting us run more boost,” says Nick. “The 5.0 engine definitely has a different computer, and it is letting us do things previous computers didn’t.” For example, Nick cites the variable valve timing as letting them swing the cam around and vary the lift and duration moreso than engines prior to it. “This engine is sick,” says Nick. He thinks that when they crank it up to 15 or 16 psi, they might see as much as 800 horsepower…on an otherwise stock motor. “These heads are amazing, they flow so well that we’re not sure we can even find a limit yet.

“Right now we’re just driving it around, feeling it out,” he says. In the meantime, they are also working on a built 5.0 engine with ported heads and different cam grinds. “The stock mass air sensor can flow as much air as we need, which is a huge plus.” Still, for now this turbo kit is in-house only, and Nick admits they have a lot more to learn about this engine. “It is still so new so we have a lot to figure out. The variable valve tables are very complicated so we’re still trying to figure out how to get the most out of this engine.” Nick says that when they do figure everything out though, “It’s gonna be evil.” No doubt Nick, no doubt.