Project Guide: The 2005-2014 "S197" Ford Mustang


Project Guide: The 2005-2014 "S197" Ford Mustang


If you’re looking for a fun, first-time project car, a 2005-2014 Mustang is an excellent choice. They feature attractive, retro-inspired styling, modern mechanicals, and robust construction. There weas a lot of hype when introduced, and the aftermarket jumped in with both feet. Fortunately for us, Ford sold a heap of them so used examples are plentiful and inexpensive. Since they’re relatively new, you’ll spend less time fixing old car issues (like rust and worn-out parts) and more time making it faster. It’s the perfect recipe for a fun, low-stress project.

Exclusive Chassis for Mustang

S197 Mustang monocoque

The 2005-2014 Mustang , also known by the "S197" chassis code, was a game-changer for Ford. It was the first time in the Mustang’s history that it got its own platform. Previous platforms were parts-bin specials or compromised for Mustang use. By the late 1990’s, Mustang sales justified its own chassis, and Ford stopped messing around and realized the Mustang deserved its own platform.

Durable powertrains, production-friendly assembly, and anti-corrosion materials result in a Mustang that’s reliable, easy to work on, responsive to changes, and requires minimal “fixing.” After all: less fixing is more time having fun!

The Prospects

S197 Guide Model Layout

During its ten-year lifespan, the S197 received several different V8 powertrains and a facelift in 2010. Let’s cover the mechanical differences, as that’s where the meat is.

4.6L 3V

  • 4.6L 3-Valve Modular V8: Three valves? Yeah, that’s not a typo. These engines are in 2005-2010 Mustang GTs. The 4.6L 3-Valve engine featured two intake valves and one exhaust valve. To move around the S197’s added heft, the Mustang GT needed a more powerful engine than the previous-generation’s 260-horsepower 2-valve snoozer. Sure, Ford could’ve grabbed a 4.6L 4-valve engine from 2004 Mustang Mach 1 and done all right. But no…the 4-valve engine was deemed too expensive. To “save” costs, Ford’s idea was to split the difference between the 2-valve and 4-valve and develop a 3-valve cylinder head with variable valve timing. Internally, the 3-valve was sold as “4-valve performance at a 2-valve cost.” In reality, the 3-valve engine performed marginally better than the 2-valve but cost Ford about the same as a 4-valve. The result was an adequate 300 horsepower and 320 lb-ft of torque. Lackluster performance aside, the 3-valve engine proved to be very durable. High milage engines should have their timing chains, camshaft variable timing solenoids, and oil pumps replaced—but it’s not all that hard, and all can be done without removing the engine.

5.0L Coyote V8

  • 5.0L "Coyote" V8: There’s enough information and stories about the development of the “Coyote” V8 engine to fill a whole book, so we’ll just cut to the chase: If you’re serious about naturally aspirated engine performance, the Coyote 5.0L V8 in the 2011-2014 Mustang is the one to have. Engineers made a “wish list” of what it would take to make real power out of Ford’s Modular V8 engine, and the Coyote is the outcome. The big improvement was the cylinder heads, which feature smaller hydraulic lash adjusters that allow improved, “raised” intake port geometry. The raised ports triggered a cascade of benefits, including improved intake manifold shape and volume. Independently variable intake and exhaust timing was a game-changer to meet both performance and emissions requirements. The result is an engine that leaves very little naturally aspirated performance on the table—while still running 87-octane fuel. All S197 Coyotes made 390 lb-ft of torque, with early versions featuring 412 horsepower, and later versions making 420 horsepower.

5.0L "Road Runner" Boss 302 V8

  • 5.0L Boss 302, aka "Road Runner" V8: What little performance the Coyote left on the table, the Boss 302 (dubbed “Road Runner”) engine gobbled up. The Boss motor added CNC-ported cylinder heads and a short-runner “ram” manifold to boost power to 444 horsepower at 7,400 RPM and 380 lb-ft of torque at 4,500 RPM.

GT500 5.4 SC V8

  • Supercharged 5.4L 4-Valve Modular V8: Big news for 2007 was the return of the legendary Shelby GT500 nameplate. Like the previous-generation 2003-2004 “Terminator” Cobra, the GT500 featured a positive-displacement supercharger between the cylinder heads, but this time the heads were spread a bit further apart as the 2007-2014 GT500 engine block was a “tall deck” 5.4-liter modular engine. Cylinder heads plucked from the Ford GT program helped the GT500’s 5.4-liter engine reach 500 horsepower and 480 lb-ft of torque. Later model years bumped output to 550 horses and 510 lb-ft.

5.8L "Trinity" SC V8

  • Supercharged 5.8L 4-Valve "Trinity" V8: The traditional “mod motor’s” swan song was the 2013-2014 GT500, with a staggering (for the time) 662 horsepower and 631 lb-ft of torque. The power bump came in part from a larger bore that ditched conventional cylinder liners and instead used plasma transferred “spray bore” cylinder lining. The result was 351 honest-to-goodness cubic inches. The Trinity GT500 engine was the high-water mark for the Ford’s Modular engine program.

Tremec TR-3650

  • Tremec TR-3650 Five-Speed Manual: One of the few carryovers from the previous generation Mustang was the 5-speed Tremec 3650 transmission. Far from indestructible, it more than met the needs of the average enthusiast, however using a balky “semi-remote” shifter can be problematic (an issue that is shared with its replacement, the Getrag MT-82). The semi-remote shifter mechanism bridges between the transmission and the body to transmit less noise and vibration from the transmission (which is attached to the engine) to the shift knob. However, that means the “gates” of the shifter can move around when the engine torques over. The result is missed 2-3 shifts. Tremec rates the 3650 as capable of handling 360 lb-ft of torque.

Getrag MT-82

  • Getrag MT-82 Six-Speed Manual: In 2011 the Coyote V8 engine was backed by an all-new 6-speed transmission: the MT-82. The new gearbox received much fanfare for its smooth action and feel—when not hurried. Where the MT-82 excelled in refinement, it failed in precision under heavy load. Blame again rests with the semi-remote shifter mechanism. The Getrag MT-82 in 2011-2014 Mustangs features a 1:1 5th gear and an unofficial 380 lb-ft torque rating.

Tremec TR-6060

  • Tremec TR-6060 Six-Speed Manual: The GT500’s massive torque required a transmission capable of handling it. The Tremec TR-6060 is an evolution of the venerable T-56 six-speed transmission with a semi-remote shifter for Mustang duty. Its torque capacity is a healthy 600 lb-ft. Fun fact: improvements to the design led to the wildly popular aftermarket Tremec Magnum series of transmissions.

Ford 5R55S Automatic

  • 5R55S Five-Speed Automatic: Ford’s automatic transmission game finally got with the program with the introduction of the 5R55S automatic transmission. With five forward speeds, the 5R55S put the AOD and 4R70W slushboxes out of their misery. The 5R55S auto backed the 4.6L 3V engine in 2005-2010 Mustangs, and with a nominal torque rating of 550 lb-ft, it could more than handling anything a 3V engine was going to dish out. The shifting and lockup strategies also were massive improvements over the previous automatics, making these automatic transmissions (shocker) not annoying to drive!

Ford 6R80 Automatic

  • 6R80 Six-Speed Automatic: With the new Coyote engine came a new six-speed automatic transmission—and it was good. Finally! A stout, world-class automatic overdrive transmission from Ford! And if the factory 590 lb-ft torque rating isn’t enough, the aftermarket is awash with bits to make it survive enough grunt for 8-second quarter-mile passes (or quicker).

What Is The Market Like?

S197 Guide Cost comparison

2007 Shelby GT500

The Market for S197 Mustangs is interesting right now. There is a wide price range between the 2005-2009 GTs and the GT500s. The hands-down bargain is 2007-2012 GT500s. They’re not inexpensive…but good, clean, low-mile examples are out there in the low 40s, or even high $30,000 range. Most owners bought them and socked them away, only to find that newer models have stolen the market spotlight. The result is GT500s haven’t appreciated as expected.

2012 Ford Mustang Boss 302

The driver’s car of the generation is the 2012-2013 Boss 302, and it’s reflected in their values. Boss 302s fetch similar money to GT500s.

2005 Ford Mustang GT

If you don’t mind leaving some performance on the table in exchange for more money in your wallet, shop for a clean 2005-10 Mustang GT with the 4.6L 3V engine. (2010 Mustang GTs are odd ducks, as they received the facelift…but didn’t get the Coyote engine.) They’re a fraction of the cost of 2011-14 Coyote-powered cars but share much of what else makes the S197 chassis great.

2011 Ford Mustang GT

The sweet spot of S197s is the Coyote-powered 2011-2014 Mustang GTs. You pay a bit more for the Coyote engine, but if you’re looking for big performance in an accessible package, the Coyote is hard to beat.

Lets Go Shopping!

2005-2014 Mustangs aren’t really “classic” or “collectable” cars yet, so standard used car practices apply. That also means they’re affordable for the average enthusiast. Buyers have a few things going for them:

  • Young Age: These cars are new enough that you’ll find them at retail used car lots, which adds shopping options and keeps prices reasonable for private party sales.

  • Ample Supply: S197 Mustangs are plentiful, so don’t be afraid to pass on a particular prospect. There are plenty of fish in the sea.

  • Longevity: Don’t shy away from S197 Mustangs with high miles. If a prospect doesn’t make bad noises, 150,000+ miles is not an issue.

Most enthusiasts gravitate to coupes with manual transmissions, but the automatic transmissions in S197 Mustangs actually doesn’t suck…and convertibles are a lot stiffer than previous generations. Again, V8s are plentiful, so buying a V6 car and planning a swap really won’t save you any money. You’ll spend less time hunting for parts buying a V8 car with an engine that needs to be rebuilt than going the V6 and swap route. All 2005-2014 Mustangs share the same suspension layout. Ford just tuned each model with different shocks, springs, and bushings.

Where To Look: S197 Mustangs are still on retail used car lots, so that’s an option that doesn’t exist for older Mustangs. Craigslist, Facebook Marketplace, Autotrader, and Bring a Trailer are all great places to shop.

Do An Inspection: Beware: there is a lot of junk out there. The first clues to a car’s condition are the photos in the advertisement. If the seller didn’t bother to wash the mud off or clean the straw wrappers and Gatorade bottles off the floorboard, how seriously did they maintain the car? Photos of the car wet (in a car wash bay, etc.) indicates the car may have paint issues.

Ask for, or purchase, a vehicle history report. 2005-2014 Mustangs will have a detailed, documented history since new. A CARFAX or AutoCheck report will reveal sins of past owners—though be aware that a vehicle history report is only as good as the reporting. Odometer reporting errors are common. Most importantly: if a vehicle is damaged without a police report or insurance claim, it won’t show up on a report. If something doesn’t look right, it probably isn’t.

With nearly a decade span between the first S197 (2005) and the last (2014) mileage and “ratty-ness” of these Mustangs varies. Don’t be afraid to pay a little more for a car that’s clean and well maintained.

If you’re on a tight budget, buy a car that has issues you’re comfortable fixing. If you’re a body guy, then choosing a car with body damage may not be a deal-breaker. A rattling engine may be fine if you were planning on building the motor anyway.

Warning Signs - Prior Modifications: While modifications themselves aren’t a problem—the workmanship can be. How do you know if the modifications were installed properly? Is the wiring hacked up? Are the bolts tight? If the car has been altered, inspect the craftsmanship carefully.

Warning Signs - Aftermarket Body Panels: Aftermarket hoods and bumper covers are a solid indication of crash damage and a previous owner trying to “make lemonade out of a lemon.” Look for uneven panel gaps and different color bumper covers.

Warning Signs - Rust: Rusty body panels are rare on S197 Mustangs. If there is rust, it’s likely a result of a poor body repair. Run away.

Warning Signs - Air Bag Light: If the air bag light is on, the air bags are not only missing, but the car was likely wrecked. Take it for a drive. There’s a lot of these cars out there, so if something doesn’t sound, smell, or feel right, move on.

Warning Signs - Air Conditioning Inoperative: Air condition failures on these cars are rare because they aren’t that old. If the air conditioning doesn’t work, check for front-end body damage.

Warning Signs - Engine Noise: There is good and bad news here. It’s common for the camshaft timing components to wear out on 4.6L 3V engines, and they make a racket. However, it’s not always terminal. Replacing the timing chains, variable valve timing solenoids, and oil pump should be on the list for every high-mileage 4.6L 3V engine. The 5.0L Coyote engines were plagued with engine “ticks,” but such noises are not terminal. They’re just annoying.

Warning Signs - Transmission Issues: News flash: manual transmissions in Mustangs are often abused. There is no such thing as “it just needs a new synchro.” If there’s a crunch, it’s likely junk. Plan on a full rebuild or just finding another gearbox. Automatic transmissions feature the common auto trans warning signs: slipping or clunking when changing gears and shuddering when the torque converter locks up, etc. The good news is parts (or even used transmissions) are readily available.

Modification Time!

Okay, now we're getting to the good part! Mustangs in general have always been a great canvas for modifications, and the S197 is no different.

Coyote Mustang CAI

Cold Air Intake: An easy way to pick up some power is to install a “cold air intake.” These typically include a freer-breathing air filter, larger air box, and a larger intake tube. Because the Mass Air Flow (MAF) sensor samples the flow through the air intake tube, some cold air intake kits will require the PCM to be re-tuned to compensate for the different size tubing. Holley’s iNTECH cold air intakes add power without PCM retuning.

S197 cat-back

Cat-Back Exhaust: A popular modification is a cat-back exhaust system. Power gains are modest, so this modification is more for more aggressive sound. Hooker Blackheart offers a lot of options: from simple axle-back systems (with and without mufflers), to 3-inch full cat-back systems.

Headers: Hooker long-tube headers really uncork a Mustang engine but are limited to race-only applications. For street applications, Hooker makes some short-tube headers that retain the factory catalytic converters.

Intake Manifold: Going further down the naturally aspirated path leads us to the intake manifold. Ford Performance Parts and Holley both offer popular options. However, unlike intake manifolds for old-school small-block engines, expect modest performance gains on modern 4.6L 3V and Coyote engines. Often these higher-flowing intakes give up a little torque in exchange for top-end punch.

S197 Camshafts

Camshafts: Swapping cams on 4.6L 3V and Coyote engines is a little more complex than a pushrod engine, but it’s not impossible. However, these modern multi-valve Ford engines breath very well with the factory cams. Bigger cams offer more thump, but there’s lower hanging fruit on the performance tree.

S197 Cylinder Heads

Cylinder Heads: The factory Ford cylinder head castings flow very well on both 4.6L 3V and Coyote engines, so aftermarket options are limited to CNC ported versions of the factory head castings. Serious race engines will require CNC ported heads, but the factory heads support most sensible street horsepower levels.

S197 Stroker Kits

Stroker Kits: There’s no replacement for displacement, and that holds true for Modular and Coyote engines…however the tight bore spacing on these engines means stroking is the only real way to increase displacement. Piston speeds are already quite high on these engines, so while modest displacement increases are possible, they’re not very popular.

ProCharged Mustang

Supercharging: THIS is where you make power with modular and Coyote engines. Modular engines LOVE supercharging (probably due to the multivalve engines’ free-breathing cylinder heads and detonation-resistant combustion chambers), so blowers are extremely popular. A plethora of systems are available that feature both centrifugal and roots style blowers. Supercharging is a well-beaten path with lots of tuning support.

S197 Turbocharging

Turbocharging: On paper, turbocharging is the best power adder—but packaging, heat, and finding tuning support can be a challenge. If you’re considering a turbo kit, we suggest working with a shop that has experience (and success) with a particular system.

S197 Nitrous

Nitrous: Nitrous is the easiest path to more power. NOS offers both fogger and plate systems for 2005-2014 Mustangs that add 150 horsepower at the push of a button.

S197 Clutches

Clutches: The factory clutches on S197 Mustangs are quite good. (Note: GT500s come with a twin disc clutch from the factory.) However, adding 100 more horsepower over stock probably requires a better clutch. There’s a wide range of clutches available for 2005-2014 Mustangs but take our advice: don't overdo it. Nothing ruins a car more than a touchy, chattery racing clutch. Be realistic about your engine's output and buy a clutch that meets that need. Avoid clutches with solid hubs on street cars. They make transmissions noisy.

S197 Manual Trans

Manual Transmission: The best way to address the shifting issues with the factory manual transmissions is to replace them with Tremec’s excellent Magnum XL. It’s an evolution of the slick and beefy TR-6060 gearbox that features a shifter mounted in the tail shaft housing—eliminating the woes of the factory semi-remote shifter setup. Complete, bolt-in kits are available from multiple Tremec dealers to simplify installation.

Automatic Transmission: 5R55S and 6R80 automatic transmissions are worth keeping and upgrading. Rebuilding a 6R80 transmission with a stronger aftermarket intermediate shaft and better clutches is all it takes to build a 1000-hp capable slushbox.

S197 Suspension Mods

Suspension: This is a place where the S197 Mustang is head and shoulders above previous generations. While still retaining a live-axle rear suspension and struts up front, the layout and geometry is not terrible. Spring, shock, and sway bar options about, but the company with the most comprehensive offering for S197 Mustangs is Kenny Brown Performance. They even offer their innovative K-Link rear suspension that offers a host of benefits over the factory Panhard Bar and other aftermarket Watts links.

S197 Mustang Brakes

Brakes: Ford finally put good factory brakes on a Mustang with the 2005-2014 models. The best factory brake setup was the 2013-2014 GT500, and Ford Performance Parts sells it as a complete kit for retrofitting earlier models. On the aftermarket side, Baer offers a wide range of brake options for S197 Mustangs. Kenny Brown Performance sells some specialized Baer systems specifically tuned for track-focused Mustangs as well.

Do Your Homework, Then Get To Work!

2005-2014 Mustangs are rewarding project cars. They’re simple, easy to work on, and aren’t too crusty (yet). Support from the internet “hive” is good—if you can wade through the bad advice. With that in mind, here’s a shameless plug for book this author’s book: How to Build and Modify: 2011-2014 Mustang. It’s “the bible” for S197 Mustangs—especially Coyote-powered models. You can get an autographed copy at or an unsigned one from your favorite book retailer!

Time to go shopping and find a fun S197 Mustang project!

S197 Mustang drag car


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