The RTR Spec 5 Ford Mustang Is Almost As Powerful As A Porsche 918

Well, the V8 version of the S650 Ford Mustang is proving to be quite receptive to simply enormous amounts of power, isn’t it? In the last year or so, we’ve seen tuned efforts from Roush, Shelby, Hennessey and Clive Sutton, all of which dabble in the dark art of sticking a whacking great supercharger on the car’s 5.0-litre V8 to produce supercar-bothering power outputs.

Now, though, there’s a new one along, and it comes from American outfit RTR. The tuner, founded by Ford-affiliated drift merchant Vaughn Gittin Jr., has already cooked up three upgrade packages for the S650, aptly named Spec 1, Spec 2 and Spec 3. So you can guess what this fourth one’s called, right?

Yeah, no. RTR’s skipped one entirely, and this is the Spec 5. We can see why it’s missed a whole number out, though, because this is one of the most powerful S650s we’ve seen yet. A 3.0-litre Whipple supercharger works in tandem with a new intercooler and a Borla cat-back exhaust to bump power up to ‘over’ 870bhp. Torque, meanwhile, now sits at 660lb ft.

Those figures are up from the 500bhp and 418lb ft you get on even the most potent 5.0-litre Mustang from the factory, the Dark Horse – and that’s the US model, not the slightly emissions-neutered one we get in Europe. More to the point, it’s considerably more power than the 815bhp produced by the upcoming Mustang GTD, and sees the output knocking on the door of that of the Porsche 918 Spyder.

Elsewhere, the Spec 5 has been treated to a widebody kit with new composite front and rear quarter panels, sills and bumpers, all of which sit neatly over the original items without any exposed mounting points. You get a host of new carbon bits too, including the front splitter, side skirts and rear diffuser.

Chassis-wise, it’s been fitted out with RTR’s adjustable coilovers and anti-roll bars, new two-piece front brake rotors and a set of 20-inch forged alloys wrapped in Michelin Pilot Sport 4S tyres.

All this can be yours in the States from $159,999 (around £120,000), and that includes a standard Performance Pack Mustang GT. You can get it with a six-speed manual or 10-speed auto, both of which should keep you rather busy with all that power on tap, and RTR is only doing a maximum of 50 a year.