To celebrate the racing heritage of the new Mustang Boss 302, a limited number of Boss 302 Laguna Seca models are available, named for the track where Parnelli Jones won the 1970 Trans-Am season opener in a Boss 302. Aimed at racers more interested in on-track performance than creature comforts, the Boss 302 Laguna Seca has increased body stiffness, a firmer chassis set-up and an aerodynamics package carried over almost in its entirety from the Ford Racing Boss 302R.

Driving the 2012 Mustang Boss 302 was intended from the outset to be a visceral experience, packed with raw, unbridled performance across the spectrum: Acceleration, handling, braking, and top speed are all equally matched for perfect balance on a car operating within the framework of legally defined safety, noise and emissions regulations.
The team at Ford wanted to offer their fellow Mustang enthusiasts something really special – a beautifully balanced factory-built race car that they could drive on the street. The Boss 302 isn’t something a Mustang GT owner can buy all the parts for out of a catalogue or that a tuner can get by adding a chip. This is a front-to-back re-engineered Mustang with every system designed to make a good driver great and a great driver even better.

With 412hp (307kw) from 5.0 litres, the all-new 2011 GT engine was already an incredible performer. But to achieve the high-rpm horsepower that would make the engine competitive on the track, a new intake was essential. The resulting runners-in-the-box plenum/velocity stack combination the engine team developed was impressive enough that it got the green light after one short drive.

Helping the intake build power, revised camshafts using a more aggressive grind are actuated with the same twin independent variable camshaft timing (Ti-VCT) mechanism used on the Mustang GT. More aggressive control calibration yields 444hp (331kw) and 380 lb.-ft (515nm) of torque, while still offering a smooth idle and low-end torque for comfortable around-town driving.

A race-inspired clutch with upgraded friction materials transmits power, while a short-throw, close-ratio six-speed manual transmission handles gear change duties.
Power is delivered to a 3.73 ratio rear axle using carbon fibre plates in the limited-slip differential to improve torque handling and longevity. For those who want even more precise control over power delivery, a torque-sensing (Torsen) limited-slip differential is an available option coupled with Recaro front seats.

Sounds like the Boss!

While the powertrain team defined output targets that would yield an ideal balance with the chassis, another team made sure the car made the kind of sounds owners and enthusiasts would expect from a Mustang Boss.

Up front, a Boss-specific intake system is tuned to feed the engine with minimum restrictions. A retuned induction sound tube provides concrete aural evidence of what’s occurring under the hood. And, in the Boss exhaust system engineers really had some fun.

Based on the Mustang GT exhaust system which already had excellent performance, the Boss 302's exhaust system was tuned for a unique sound. Combined with the rush of the intake, the exhaust system really envelops the driver in V8 sound.

Every Boss features a unique quad exhaust system: Two outlets exit in the rear similar to a standard Mustang GT. The other two outlets exit to either side of the exhaust crossover, sending exhaust through a set of metal discs that act as tuning elements before the pipes terminate just ahead of the rear wheel opening. Visually subtle, the side pipes flow very little exhaust but a lot of exhaust sound, providing a sonic experience unlike any other Mustang.

Drivers can choose from five settings for their shocks. One is the softest, two is the factory setting and five is the firmest. A driver can drive to the track on setting two, crank it up to five for improved response on the track, then dial down to one for a more relaxed ride home. What’s unique is that drivers will find – thanks to the way the suspension works as a complete system – the softest setting isn’t too loose and the firmest setting isn’t too controlled; each step just provides additional levels of control. Also unique is the method of shock adjustment. Ditching the weight and complexity of electronic wizardry, the Mustang team opted for traditional race-style hands-on adjustability – similar to the Gabriel shocks available on the original Boss 302.

The shock adjustment is right at the top of the shock tower, built into the rod and easily accessible from under the bonnet or inside the boot. A small flat-head screwdriver is used to turn the adjustment screw between one and five.

To complement the suspension, the speed-sensitive electronic steering system has been retuned to maximise feedback and road feel to the driver. The driver is also given the option of fine-tuning the steering feel to his liking by selecting one of three settings through the instrument cluster menu: Comfort, normal and sport modes help offer track-tuned steering when desired without sacrificing low-speed maneuverability in parking situations and everyday commuting.

Similarly, Boss receives unique traction control system (TCS) and electronic stability control (ESC) settings to help drivers achieve maximum performance whether on the street or at the track. Both systems can be completely disabled in controlled track situations where maximum driver skill is utilised, or fully engaged for maximum safety during normal driving or in less-than-ideal traction conditions. Intermediate sport mode allows drivers to push their cars hard at the track without completely disabling the safety systems, permitting more aggressive driving before the TCS and ESC systems intervene.

Brakes, wheels and tyres

Working in concert with the suspension upgrades, the Boss 302 receives unique, lightweight 19-inch black alloy racing wheels in staggered widths: 9 inches in front, 9.5 inches in the rear. The Pirelli PZero tyres are sized specifically for each end of the vehicle, with the front wheels receiving 255/40ZR-19 tyres while the rear stays planted thanks to 285/35ZR-19 rubber.

The combined suspension and tyre package allows the Boss 302 to achieve a top speed of 155mph (250kph) and become the first non-SVT Mustang ever to achieve more than 1.0 g of lateral acceleration.

Boss braking is also up to the challenge, using Brembo four-piston front calipers acting on 14-inch vented rotors up front. In the back, standard Mustang GT brakes are upgraded with a Boss-specific high-performance pad compound. Combined with vented brake shields and unique Anti-Lock Brake System (ABS) tuning, Boss drivers get maximum control and rapid, repeatable fade-free stops in road and race situations alike.

The Mustang team spent considerable time ensuring the brake pedal feel met the expectations of performance drivers. Boss receives unique low-compressibility brake lines that expand up to 30 percent less than traditional flexible brake lines, allowing maximum fluid pressure to reach the calipers in the least amount of time, giving the driver a sensation of being connected directly to the brake pads. They’re the best brakes ever installed on a Mustang, and they give consistent, repeatable braking performance on the street and the track.

As a result 60-0 (96-0kph) stopping distances for the Boss are improved by approximately one metre versus the Mustang GT with available brake package; combined with suspension and engine improvements, Boss is expected to show approximately a two-second lap time improvement over the GT on a typical road race course. But the numbers tell only part of the story.

To set Boss apart, each car will have either a black or white roof panel, coordinated to the colour of the side C-stripe. Available exterior colours are Competition Orange, Performance White, Kona Blue Metallic, Yellow Blaze Tri-Coat Metallic and Race Red. Ingot Silver Metallic and Black are available on the Boss 302 Laguna Seca only.

Up front, a unique fascia and grille are highlighted by the blocked-off fog lamp openings and aggressive lower splitter, a version of the design used – and proven – on the Boss 302R race car. The front splitter is designed to function at high speeds by efficiently managing the air under and around the car. It helps to reduce underbody drag and front end lift while more effectively forcing air through the Boss-specific cooling system. At the rear of the car, the spoiler was chosen to complement the front aero treatment and minimise overall drag.

Inside, a unique Boss steering wheel covered completely in Alcantara suede complements the standard seats, which are trimmed in cloth with a suede-like centre insert to firmly hold occupants in place. Boss customers who want the ultimate seating experience can select a package that includes Recaro buckets, designed by Ford SVT in cooperation with Recaro for high performance Mustang models, and shared between the Boss and GT500.

A dark metallic instrument panel finish, gauge cluster and door panel trim also differentiate Boss from the standard Mustang, while a black pool-cue shifter ball and 'Powered by Ford' door sill plates further remind customers they’re in a special car. 

The Boss interior gets an aural kick thanks to what’s been removed. Five kilograms of sound-deadening material have been eliminated to let occupants further enjoy the intake, engine and exhaust note.

Bulletproof and blower-free

Planning began with a small group of engineers within the 5.0L V8 team. Starting with open minds and enlisting the help of two members of the original 1969 Boss 302 design team, the group began working its way toward the ultimate evolution of the new 5.0L: 444 hp (331kw) and 380 lb.-ft (515nm) of torque, along with a broad, flat output curve all the way through its projected 7,500rpm redline.

The Mustang team knew a supercharger would be the simplest way to extract significant power improvements from the new 5.0L V8, but they elected not to pursue forced induction for the 2012 Boss to stay true to the original Boss 302 engine.

The core group of engineers on the Boss 302 engine understood and respected the heritage of the name and the history behind the original engine. The first Boss 302 was a specially built, free-breathing, high-revving small V8 that gave it certain desirable characteristics on a race course – and that essence is captured in the new engine.

The team also realised the additional hardware meant more weight, the bane of any racing program and the opposite of what the Boss design team was attempting to achieve. Instead, the same technology that has made the new Mustang GT engine such a formidable force was applied to the Boss 302. In keeping with the spirit of the original, the new Boss 302 engine achieves its maximum power output at speeds at or above 7,500rpm. Unlike the original engine, however, low-speed torque and driveability are uncompromised thanks to twin independent variable camshaft timing (Ti-VCT) technology and computer-aided engineering design tools.

The development team began exploring Boss 302 concepts starting with the engine’s ability to breathe – essential to the production of horsepower. Because credible track performance requires high power production between 5,000 rpm and 7,000 rpm, the team needed a new approach to intake manifold design. Borrowing from the Ford Daytona Prototype engines, the resulting short-runners-in-the-box design virtually eliminates lag when the throttle is snapped open while producing peak power output at high rpm.

To take advantage of the racing intake manifold, cylinder head airflow was fully optimised by CNC porting the entire intake and exhaust port and combustion chamber. The painstaking machining process takes 2.5 hours per head to complete. To accompany the higher peak-power engine speed, the team had to engineer a lightweight, high-speed valvetrain and bulletproof reciprocating assembly that would not only hold together for 150,000-plus miles but also produce power at peak rpm.

Engine stresses increase exponentially as engine speeds rise, so moving up from GT’s 7,000rpm redline required significant re-engineering of many different parts. Sacrificing reliability and usability over the GT engine was never an option.

Some of the Boss-specific parts contributing to the Boss 302 V8’s output and durability include:

• Revised composite intake system with shorter runners, inspired by Daytona Prototype racing engines, for high-rpm breathing
• Forged aluminium pistons and upgraded sinter-forged connecting rods for improved strength, needed for the higher combustion pressures and engine speeds
• New high-strength alumiinum-alloy cylinder heads with fully CNC-machined ports and chambers for exceptional high-rpm airflow without sacrificing low-speed torque
• Lightened valvetrain components to provide excellent dynamic performance up to speeds well above the engine redline
• Sodium-filled exhaust valves for improved heat dissipation
• Race-specification crankshaft main and rod bearings for higher load capability and improved high-speed durability
• 5W50 full-synthetic oil with engine oil cooler for improved oil pressure and longer-lasting lubrication during extreme racing conditions
• Revised oil pan baffling for improved oil control under racing conditions and during cornering loads greater than 1.0 g

Close connection with race teams

Contrary to normal engine development protocol, the first batch of durability test engines weren’t installed in an engine dyno. Instead, thanks to a request from Ford Racing, they went straight to the track. Ford Racing challenged the Boss engine team to give them the first available Boss 302 engines. They needed engines as soon as possible to build a limited number of Ford Racing Boss 302R cars for the Daytona race. This gave the development team a fantastic opportunity to be able to get full-on race experience with the engine so early in the program.

The Boss engines have run reliably all season without a single mechanical failure. Boss 302R cars have also racked up the most laps led so far this season in Grand-Am racing.

Using race telemetry, the Boss team has been able to gather on-track data to help optimise engine calibrations, oil pan designs and cooling. In order to engage in virtual racing whenever they needed, the team used the telemetry data to re-create a hot lap at Daytona on the dyno back in Dearborn, allowing further fine-tuning.

Production engine durability testing

Despite its racing heritage – and the rigours of track-day testing – the Boss 302 V8 is still a production Ford engine, built alongside the 5.0L GT engine at Essex Engine Plant in Ontario, Canada. That means it has to meet or exceed all the standard durability testing every Ford engine is required to complete.

The high-winding engine presented a challenge: The engine had no trouble staying together at its redline, but the Ford durability dynamometers weren’t designed to operate at the speeds the Boss engine was capable of.

The Boss engine was run at its full rated output for tens of millions of cycles, eventually outperforming its specifications at every stage of testing. Engineers calculated that the test regimen was equivalent to running the Daytona 250 race flat-out more than 175 times – in a row.

Team members also devised an additional durability test specific to the Boss 302 engine – one that reflects the unique demands of Boss drivers. The engine was subjected to a regimen simulating 1,500 quarter-mile races typical of events at drag strips across the country.

Even though the production Boss engine is designed to be very close to a full race engine, it had to achieve the same vehicle durability signoff any other production engine requires. Then it went on to get the track durability test signoff too. It’s really an engineering accomplishment that a Boss owner can thrash his car on the track and still expect the same outstanding reliability that the owner of a regular Mustang GT will enjoy.

A joint project between Mustang engineers and Ford Racing, TracKey adds a second set of PCM software to the Mustang Boss 302, activated by the specially programmed vehicle key. When invoked by TracKey, the new TracMode software alters more than 400 engine management parameters, increasing low-end torque and turning the potent but well-mannered stock Boss into a competition-ready track car. Remove TracKey and start Boss with the standard key, and all factory engine settings are restored for a comfortable drive home.

From an engine management standpoint, TracKey gives users a full race car experience. It’s not for use on the street – for example, the deceleration is set up to preserve the brakes, and the throttle response is very aggressive. A skilled driver on a closed course will really appreciate the benefits.

As part of the TracKey software package, Ford engineers also devised a two-stage launch control feature similar to that used on the Cobra Jet race car. Using a combination of steering wheel buttons, drivers can set the tach needle to a desired launch rpm. Floor the throttle and the engine will rev to the preset rpm until the clutch is released, helping aid acceleration and vehicle control from a standing start.

One key, hundreds of changes

Devised during an all-night garage brainstorming session among core Mustang team members, TracKey introduces the concept known as the dual-path powertrain control module. The industry-first, patent-pending innovation allows two separate sets of engine management software to exist on a single PCM, selected through the existing SecuriLock® Passive Anti-Theft System (PATS) transceiver found in current production keys.

Anything that could possibly affect all-out performance is deleted from the TracKey calibration. Throttle limiting and torque management - any daily driveability enhancements are removed and replaced with a pure Ford Racing competition calibration.

When the red TracKey is removed and the vehicle is started with the standard key, the PCM settings are automatically drawn from the factory Boss 302 instruction set again without any additional modifications needed - a huge advantage over aftermarket tuning chips and ECU reprogramming. The convenience is useful for enthusiasts who want all-out performance at the racetrack but stock driveability for the journey there and back.

An after-hours obsession

In the early stages of TracKey development, a major challenge was the complexity of installing multiple PCM computers and switching between them. However, Ford controls engineers developed a method to choose between two unique sets of software in a single powertrain control module on the Boss 302: The dual-path PCM was born.

The 302R software is installed on the same PCM that held the stock Boss software. Then the controls engineers developed a software system to activate one or the other, depending upon which key was used to start the vehicle. Really, all the parts to make this work existed – the Ford MyKey® system was already using the PATS transceiver to perform specific actions based on the key used to start the car, and the PCM was flexible enough to handle multiple control modules.

As the project unfolded, the team was driven by the uniqueness of what they were trying to accomplish, and TracKey became an obsession. Considering the compressed time frame in which the technology was developed, motivation was essential to the creation of the finished product.

The Boss 302 Laguna Seca builds on the bumper-to-bumper improvements found on the standard Boss while further stiffening the chassis and installing an aerodynamics package carried over almost in its entirety from the Ford Racing Boss 302R. Drivers who know how to get the most from a tuned race car on a closed course are going to be amazed by what the Laguna Seca is capable of. The balance, agility and tuning of each vehicle system places the driver at the centre of the machine, completely connected to everything the car is doing.

Chassis enhancements

Laguna Seca cars are powered by the same smooth, high-winding 444hp (331kw) 5.0L V8 as the standard Boss, since the engine was already tuned specifically for road racing. Engineers then turned their attention toward delivering power to the ground most efficiently, and getting the car around a track in the quickest possible time.

Laguna Seca cars eliminate the rear seats, instead adding a cross-car X-brace that couples the structure between the rear wheels. The brace offers chassis stiffness improvements of as much as 10 percent and allows the suspension tuning – precisely calibrated by Mustang team members – to better do its job.

Standard Recaro front seats were designed by Ford SVT in cooperation with Recaro for high-performance Mustang models, and are shared between the Boss and GT500. An Alcantara-covered race steering wheel provides a solid grip for hard cornering.

Engine power routes through a six-speed close-ratio manual gearbox to a standard 3.73-ratio Torsen limited-slip differential, helping the revised rear suspension deliver maximum torque and traction under the punishing conditions encountered on the track.

Higher spring rates and a larger rear stabiliser bar – all upgraded over Boss specifications – help generate unrelenting grip. And drivers can dial in exactly the level of shock stiffness a particular track requires using the four standard, independently adjustable dampers with Laguna Seca-specific valving.

The final touch was to add the proper wheels and tyres: Laguna Seca models use lightweight 19-inch alloy racing wheels in staggered widths: 9 inches in front, 10 inches in the rear. R-compound ultra-high-performance tyres, 255/40R-19 in the front, 285/35R-19 in the rear, maintain contact with the pavement – a job that ended up being trickier than expected.

The R-compound tires on the Laguna Seca are so sticky the team had to really work on the rear suspension tuning to make sure drivers can get the most out of them. The rear stabiliser bar is the largest ever installed on a production Mustang – including any SVT product. The rear spring rate was also maximised to work with the massive rear tyres and balance the car for outstanding lap times.

While standard Boss 302 cars get vented brake dust shields to help cool the rotors, Laguna Seca models receive Ford Racing front brake ducts that force outside air directly onto the 14-inch vented front rotors, helping to eliminate brake fade and ensure hard, repeatable late braking on the track. Combined, the braking changes help refine the sense for drivers of being directly connected to the pads – an essential edge during car-to-car combat on a road course.

Added up, the further improvements to Boss Laguna Seca result in the best-handling Mustang ever, with more than 1.03g of lateral acceleration, stopping distances shortened by one metre from 60mph (96kph) over Boss, 0-100kph acceleration improvements of one tenth of a second, and an overall expected lap time improvement of one to two seconds over the standard Boss on a typical road course.

Styling evokes racing, improves aerodynamics

As a race car should, Boss 302 models with the Laguna Seca package look like nothing else on the road. A bright red C-stripe offsets either Black or Ingot Silver paint, and is complemented by a red roof panel. Red also sets off the front grille, mirror caps and rear pedestal spoiler, while Laguna Seca rear badging and unique two-tone red and silver wheels complete the transformation.

Aiding both appearance and aerodynamics, an aggressive front splitter for track use adds downforce at the front of the car, while helping channel air under and around the car. At the same time, air impacting the front end is funnelled into the radiator and brake ducts, supporting cooling even under gruelling race conditions. The Laguna Seca front splitter is really a Ford Racing piece which has been lightly adapted. It’s been tested and refined on the Boss 302R to perform exactly as required on the track; just a few changes were made so it could be adapted to the production Boss – though owners will still want to avoid speed bumps and parking blocks.

At the back, a large rear spoiler is sized to exactly complement the effect provided by the front splitter and underbody aero treatments, with the combination adding as much as 40kg of downforce at 225kph. Balance is the key on Boss, and even more so on Laguna Seca. A winning race car has to do everything well, and all the engineering that went into Boss Laguna Seca has been tested on the Ford Racing 302R. It’s not for everyone: It’s stiffer, there’s no back seat, and the aero package is designed for downforce, not speed bumps in the parking lot.

But for hard-core Mustang racers who want something they can occasionally drive on the street, to shows or whatever, Laguna Seca is the car they’ve been waiting for, and they’re not going to be disappointed.