Let’s Start With Engines
The iconic Ford 5.0 Coyote engine. Photo courtesy Vorshlag Motorsports.
Ford offered several trim levels, options and packages for the S550. Let’s start narrowing down the choices by engine.
The 2.3-liter Ecoboost four-cylinder? Built for economy, not performance, says Terry of the 310-horsepower engine. The turbos tend to build up heat, too.
The 3.7-liter V6? Not this one, either. The weight savings doesn’t overcome the cut in power, with the V6 putting out 300 horses. Terry adds that the V6 does make for a fine, economical cruiser car, if that’s what you desire.
How about the 5.2-liter Voodoo V8? You know, the one in the Shelby GT350? Don’t go for it, either, advises Terry. The unconventional combination of a flat-plane crank in a V8 creates detrimental harmonics.
“They just vibrate themselves apart,” says Terry. “Sometimes it’ll unscrew an oil filter. Sometimes it pops out a rod. They rated them for 526 horsepower. Ford overrated them and underrated the Gen 3 Coyote engine. They are a lot closer in performance on a dyno.”
Then there’s the 5.2-liter Predator V8 in the Shelby GT500. While certainly the most powerful Mustang, it does come with its drawbacks, aside from price.
“The GT500 is a real track car,” Terry says. “They’re legit fast. A lot of it comes down to that Tremec DCT TR-9070. It’s a freakin’ work of art. The GT500 is really heavy. The typical V8 GT car is about 3600 pounds. The GT500 is 4200 pounds. But the tuning of the GT500 is so good.
“However, I’m not a fan of boosted V8s,” Terry continues. “It’s generating more heat than you can get out. After a few laps, they start to pull horsepower. But they’re so fast it’s hard to feel that you lost 100 of your 760 horsepower.”
So, yeah, the GT500 makes sense–if you’ve got the dollars. We’re not just talking the purchase price. With more weight and more power comes more consumables–fuel, tires, brakes, etc.
An intriguing choice is the Mach 1, produced from 2021 to 2023. The 2021 uses the Gen 3 Coyote and puts out 480 horses and 420 lb.-ft. of torque. The following year, those numbers drop to 470 and 410, respectively. It gets a bunch of the good stuff from the Shelbys, such as the engine oil cooler, rear axle cooling system and, perhaps more importantly, the Tremec TR-3160, which the GT350 had and S650 Dark Horse uses. It is a durable, smooth-shifting, six-speed manual that Terry says is better than the Getrag MT82. Expect to pay between $35,000 to $40,000 for one, though.
The best bang for your buck comes with the Coyote V8, particularly the Gen 3 version that came out in 2018. That generation included larger valves and a dual injection system that uses direct and port injection. Those revisions increased power by 25 horses, to 460, and 20 lb.-ft. of torque, to 420. It’s important to note that the 2022-and-up models saw those numbers decrease a tad, to 450 horsepower and 410 lb.-ft. It’s plenty of power, more than $10,000 cheaper than the Mach 1, and much more widely available.
Other Things to Shop For
The inverted hat rotors on the base GT's 14-inch four-piston brakes overheat quickly and just do not cut it., according to Terry Fair. Photo courtesy Vorshlag Motorsports.
Okay, so let’s recap, you’re looking for a GT coupe, from 2018 to 2021, to get that Gen 3 Coyote V8 with the most power. Should you save a few dollars by going for that base, no-frills model? No, Terry says emphatically. He’s tried it.
“My first practice, I found out that my car was very compromised,” concedes Terry. “With the base 235mm tires, it was slower than a Gen 1 86. If you don’t have the Performance Pack 1, you’re missing out on a lot of good things. The PP1 came with 15-inch diameter, six-piston Brembo front brakes, better ABS programming, better cooling, more gauges, a Torsen limited-slip differential, tunneled front undertray, and a bumper lip splitter. This PP1 package is the better entry-level model GT to buy.”
Ford also offered the Performance Pack 2. That sounds even better, right? Not necessarily. “These look like a better track car, and if you’re planning on keeping it bone stock, they might be,” Terry says. “But the tires aren’t wide enough, the MagneRide shocks require more expense when switching to a performance damper, and they’re saddled with a variety of nice, expensive options that make it a better street car but don’t add anything to on-track performance. What the PP2 model does have is a front splitter with diffuser ducts bringing air up to cool the brakes. But that splitter can be installed on a PP1 car with ease.”
Lastly, automatic versus manual? Automatics have gotten good. Really good. Right? Yes … but.
“The automatics are fast,” says Terry. “Fast on the drag strip. Fast on the first lap on track. But they build heat and cannot shed it while on track. The 2018 model change from the six-speed automatic to the 10-speed automatic was a dramatic improvement in durability and performance, but they still have heat issues on track.. Also, if you get a Performance Pack with the automatic, you don’t get the Torsen differential.”
So what’s the S550 you want? Terry recommends a 2018-’21 GT coupe with a Performance Pack 1 and a manual transmission. If it has the more supportive Recaro seats, that’s a bonus, as the standard seats feel like something out of a 1970s cruiser, says Terry.
Before Your First Event, Do This
While Terry does not recommend buying the Performance Pack 2 due to costs, he does highly tout the PP1 front undertray and longer splitter lip from the PP2 package. If you start with a 2018-up base GT, both of these upgrades are an improvement for downforce and brake cooling. It easily installs on base 2018-2023 GT cars. Photo courtesy Vorshlag Motorsports.
The Ford Mustang delivers quite a bit of power and has quite a bit of heft. That mass and acceleration takes a toll on brakes.
“Most OEM pads and replacement street pads for the Mustang will fade or melt when subjected to track use,” says Terry. “Most OEM fluid will boil. Use a performance pad compound and brake fluid that will hold up to the abuse.”
Great pads and brake fluid are just the start.
“Good pads eventually fade after heat soaking,” Terry says. “Prevent this by directing cool air to the rotor. Use either ducted backing plates or deflectors. For the 2018-and-older cars, adding the PP1 front undertray provides diffusers that pull air up to the brake deflectors. For the earlier cars, you’ll have to provide ducting or an aftermarket diffuser in the undertray like the splitter ramps from Professional Awesome.”
What ultimately stops the car, though? That’s right: the tires. While more brakes and tires seems logical for just about any car, they’re especially important with the heavy, powerful Mustang.
“We recommend a 305 or 315 tire on an 11-inch-wide wheel,” says Terry, adding that the Mustang will easily take those widths. “Moving to these larger sizes is expensive to start with, but with larger tires comes better longevity. The performance advantage is undeniable, too.”
Terry suggests that you find the brand, model and width of tire you want first, and then decide between the 18- or 19-inch wheel options. The popular 315/30R18 works pretty well on an 18x11 wheel but is significantly shorter and can affect gearing. A 305/30R19 tire is closer to the stock tire height and fits well on a 19x11 wheel.
Want those pricey tires to last even longer? Cue in front camber.
“Add all of the camber to the front end,” says Terry. “Camber plates will typically pay for themselves within two weekends in the tire life they save. Opening the strut tower circle can unlock more camber in some camber plates.”
Don’t Do This First, Though
The Mustang comes with a big honkin’ American V8. Why not add more power? Well …
“It’s the first thing people want to do,” says Terry. “People say, ‘I want it to make more noise, more power, and I’m going to go faster because of that.’ No, it doesn’t need any more power. We held back from touching anything on the engine on our 2018 Mustang until our second year, because it’s really good.”
The chassis doesn’t need any additional stiffening, either.
“The cars are already very stiff and weigh a lot,” Terry explains. “There is no need to add more ballast to them. They do not need any bracing.”
Don’t opt for spherical bushings unless you’re running at the pointy end of the spectrum of motorsport. There’s only a minor performance gain in exchange for a major increase in noise and vibration.
Besides maybe swapping in an adjustable rear-upper camber arm to get more camber, don’t mess with adjustable arms, advises Terry. “The S550 rear suspension geometry works well,” he says. “Unless you cause some geometry issue that requires an adjustable arm to fix, it is unlikely you need a different-length arm.”
Speaking of that rear suspension, don’t over-lower the rear, warns Terry. “There is some self-correcting geometry in the S550 rear suspension that can save a driver when the car is mildly overdriven,” he says. “Lowering the car too much will negate this geometry.”
More caster is unnecessary as well unless you’re running a top-speed event.
Lastly, go back to that engine, don’t overrev it. It sounds cool even before that point–and performs better, too. “The Coyote engine makes a lot of torque,” Terry says. “Drive it so you can use that torque. Revving it to the redline causes some issues with heat and valvetrain failure. These engines are robust and can last tens of thousands of track miles, but not if they’re wrung out.
Feeling Frisky? Then Consider These Mods
Coil-overs offer some gains in the handling department. Photo courtesy Vorshlag Motorsports.
You’ve got the better brake pads, brake fluid, bigger tires and more camber, but you want more. No problem. There are a few other things you can easily do to gain some performance.
Go with coil-overs. The Mustang, according to Terry, is woefully undersprung, and you can’t get the spring rates you need without swapping in some performance coil-overs. “Changing springs to stiffer rates allows you to provide some balance to the car without having the sway bars maxed out,” says Terry. “It reduces roll and turns the tires on quicker. Damping that has a steeper compression curve and enough force to work with the stiffer springs keeps force on the tires and makes them work consistently.”
Speaking of sway bars, aka anti-roll bars, that’s not a bad change to do, either. Adjustable ones can help you tune the car with little penalty to geometry. While you’re at it, replace the anti-roll bar bushings so the bar can rotate with zero bind. Bind results in lifting a wheel. When the wheel is in the air, you have zero grip.
As mentioned before, if you’re going to do anything to that rear suspension, go with one replacement arm to increase rear camber. More camber ups your performance and increases tire life. That’s a win-win situation.
Add a six-point harness to your Recaro seats. If your Mustang didn’t come with that, get a good aftermarket one. “Not just for safety,” advises Terry, “but to hold you in place so you can concentrate on operating the controls rather than holding yourself in place. This is a system that involves seat mounts, the seat, a harness and a roll bar.”
While you’re thinking safety, a fire-suppression system can save your car–and maybe even your life. “The weight and expense seems like a lot until you lose a car to fire,” says Terry. “There are many ways a fire can start on track that can consume a car. Modified cars are more susceptible, but even completely stock cars can cause a fire. Reasonably priced systems are available.”
Adding hood vents is also advantageous. First, it improves engine cooling. Second, it reduces front-end lift. “Kits are available to make this easy,” says Terry. “It’s not the major fabrication job it used to be.”
Photo courtesy Vorshlag Motorsports.
Done all this? Okay, finally, let’s talk power. Three things can help get you some quick power–a cold-air intake, long-tube headers and a tune. “All three alone do very little,” says Terry, “but do all three and more torque and some upper-end horsepower shows up–30 to 40 at the wheels. Make sure that any tune you have done retains a linear throttle. Having a linear throttle provides better throttle modulation. Work with your tuner to provide a road course-safe tune with less ignition timing and maybe a few horsepower less than the ultimate kill tune that street racers might otherwise chase.”
More power? Great. How about less weight, too?
“Take the back seat out,” says Terry. “It’s about 60 pounds. You can’t fit anybody back there anyway unless you have no legs or you’re 2 years old. That’s some weight, but most of the time we’re taking the back seat out so we can put a four-point roll bar in … and that weighs about 60 pounds. The front seats are kind of heavy … A proper race seat with a slider and a base, you might lose 15 pounds. The front fenders, hood and trunk are all aluminum. If you use carbon, you might lose 15 pounds for the hood, 10 pounds for the trunk. The doors are heavy. They’re 84 pounds apiece. Replace that with carbon, but they have zero side-impact bars inside. So that requires a cage. Guess what? That weighs 175 pounds. It’s a wash. In my S550, we’ve touched just about every system for weight, and it still weighs 3600 pounds.”
All Revved Up for an S550?
Photo courtesy Vorshlag Motorsports
So now you know which S550 to buy and what your plan of action is. What’s one more perk of the S550? It’s got a wealth of support and there are plenty of cars out there.
“It was the number-one-selling sports car globally for many years,” says Terry. “We’re going to be talking about these cars for the next 20 years. Most of the people who would be a customer for a brand-new Mustang are going to look at the S550. The S650 wasn’t enough better, it’s only gotten heavier and more expensive. The Dark Horses are significantly better than the base 2018-2023 Mustang GTs, but it’s a $70,000 car. You need to spend like $55,000 for a new Mustang that’s not terrible. That’s just hard to swallow for some people. So, they can go out and spend $20,000 to $30,000 and get a really good S550 and beat the snot out of it. The engines last forever if you don’t overrev them. The transmissions are pretty good–you just got to know at some point you’re going to have to replace them. It’s a really good performance bargain, and you can beat a 911 on track with very little effort with a Mustang.”
