The "Level 2" pack was developed as part of a skunkworks project even Ford management didn't know about.

The pony car war continues to heat up – and you can give credit to a team of Ford Mustang engineers who decided to create their own skunkworks team, keeping their efforts secret until they knew they could deliver a package that would outperform their arch-rival over at Chevrolet.

Ford has been billing the 2018 update of the Mustang GT as the fastest ever, yet it looked like it was going to fall just a little bit short with the $3,995 GT Performance Pack.

So, Tom Barnes, the Mustang’s vehicle engineering manager and a handful of other team members quietly went to work during their off-hours seeing if they deliver something better. The results? The $6,500 Performance Pack Level 2 which is designed to move the GT a big step closer to the performance and handling of the GT350.

“A passion to create something special is what really drove this project,” said Barnes. “And that really showed in the off-the-clock way we went about doing our work.”

The team quietly used tool like 3D printing to develop Level 2 features like the rear spoiler.

Known inside as simply “Level 2,” the package gives the Mustang the sort of boost it desperately needed to compete with the 1LE package Chevrolet now offers for the Camaro.

That’s not to say the “base” Performance Pack is a slouch. It turns the pony car into the fastest Mustang GT ever, churning out 460 horsepower and hitting 60 in less than four seconds. In that configuration, it makes five more ponies than the Camaro – though 35 fewer pound-feet of torque. (And by comparison, the Shelby boosts things up to a throbbing 526 hp.)

(Leaner, faster, more high-tech: Click Here to see new Ford CEO Hackett’s vision of the future.)

The Level 2 package returns to Mustang roots, trading in the latest 10-speed automatic for a more familiar six-speed manual transmission.

For that $6,500, you’ll get “streetable track and competition tires,” staggered-width Michelin Pilot Sport Cup 2 rubber wrapped around unique 10-spoke wheels. A warning for those in colder climates: you’ll either want to garage the car or swap out the Michelins for something more suited for winter once the temperature drops below freezing.

The Level 2 pack includes grippy Michelin Pilot Sport Cup 2 tires on 10-spoke grayed-out wheels.

To keep the Mustang glued to the pavement, the Level 2 package includes a redesigned front splitter and a unique rear spoiler. The springs are stiffer, as are the stabilizer bars. There are new MagneRide adaptive shocks, and nanny controls like the car’s ABS and stability control – as well as electric power-assist steering boost — have been aggressively retuned.

While the Performance Pack 2 doesn’t touch the engine itself, there’s a larger radiator meant to keep it cool under aggressive driving. And there’s a Torsen rear differential to ensure torque goes where it’s needed most. To slow the car down, Ford now packages the Mustang with six-piston Brembo brakes.

Put it all together and “It will just beg you to go faster,” said Jamie Cullen, Mustang’s dynamics chief.

He and the rest of the skunkworks team spent lots of nights and weekends working up their ideas. They were assisted by some of the latest high-tech development technology Ford had to offer. They came up with their ideal rear spoiler, for example, by repeatedly testing new designs they produced on a 3D printer.

Inside the 2018 Mustang GT with the Level 2 package.

(Owners rate Ford as “ideal” in new study. Click Here for more.)

“Our targets were aggressive, said aerodynamics specialist Jonathan Gesek, “and we nailed them.”

A 2018 Ford Mustang GT with the Performance Pack Level 2 won’t roll into showrooms until things warm up next spring, but the automaker says it will begin taking orders immediately.

(Ford’s newest Super Duty model nudges the $100,000 mark. Click Here for the story.)