The Ford Mustang Dark Horse was bred for the track not the drag strip, but now the Hennessey H850 package adds more muscle into the mix.

The seventh-generation S650 Mustang has a new range topper from launch, known – rather ominously – as the Dark Horse. The idea here was to rid the Mustang of its crowd-killer persona and equip it with a chassis and suspension set-up designed to handle like a true sports car, not just some muscular barge.

In practice that meant making additions such as MagneRide suspension and a Torsen limited-slip differential. It also gets a front strut brace, rear K-brace, larger rear anti-roll bar and beefed up front dampers. Under the hood, Ford has ransacked the GT500 parts bin for some connecting rods, and the car gets a dual throttle body too. There’s even been a few mods made to better prepare the car for intense track use. For example, you get an auxiliary engine oil cooler and a lighter coolant radiator with better fans than standard. On top of that, Dark Horses with an auto box get a transmission cooler too.

There’s plenty of other fine nuances to the Dark Horse, but the general take home is that if there’s ever been a Mustang best suited to track days, this is it. And don’t worry about any sort of identity loss – this full-fat muscle car produces around 500hp from its Coyote V8, it just has the running gear to cope with it all now too.

Still, when it comes to power, more is more, right? Well, that’s the Hennessey way of thinking…

rear of Hennessey H850 Dark Horse

Hennessey H850 Dark Horse Specs

Let’s make it abundantly clear. When Hennessey says they make ‘fast cars faster’, they’re talking about when going in a straight line. If you’re after some sort of apex-munching time attack kit for your Dark Horse, you’ll have to look elsewhere.

What Hennessey has done is rather true to character. They’ve added a high-performance supercharger and a high-flow air induction system, upgraded fuel injectors, and a new fuel pump. A HPE ECU is then tasked with making it all run smoothly. The end result? 850 horsepower and 650lb ft of torque (compared to 418lb ft stock). As far as horses are concerned, that’s a 70% increase in power.

Some tuners might then consider bulking up the car’s chassis too, but not on this occasion. To be fair to Hennessey, the way that Ford talk about the Dark Horse, it should be well equipped to handle huge power even with stock running gear.

The cherry on top of the Hennessey H850 package is the styling. On the subtler end of the spectrum, the Dark Horse gets a new carbon-fiber front splitter, side skirts, and rear wing. The forged aluminum alloys are a new design too. And as for the bold ‘Heritage’ decal pack, well that’s optional. So, whether you want a sleeper or a… shouter (?), Hennessey’s got you covered.