GT500 learnings make GT350 better, easier to drive
“Make it more confident and intuitive to drive.” That was the feedback current owners of Ford’s wild-child, track-rat, flat-plane-crank, manual-only Mustang Shelby GT350 offered when the development team went asking. Although buyers of the Shelby GT350R tend to be pretty accomplished shoes, buyers of the “base” GT350 are more likely to drive their cars daily and take them to a track much less frequently. As such, these owners tend to be less practiced and more fearful of wadding up their babies. The team kept this wish in mind as it pushed the current Mustang platform to new levels of performance while developing the forthcoming GT500 and is now rolling out a new GT500 with higher performance limits that are easier to reach. (The GT350R remains unchanged for 2019.)
Assisting with the aforementioned development was veteran race driver Billy Johnson, who’s spent three years working with the team while also racing Ford GTs and prepping the Mustang GT4 race car, which he’s campaigning this year. Billy apparently shares Randy Pobst’s knack for articulating how a car feels and helping direct changes to make it feel better.
Perhaps the lowest-hanging chassis-development fruit is improving tire grip. Tire Rack can help you do that to your car right now, but when you’re the Mustang team, you don’t call Tire Rack—you work with Michelin to custom-tailor a tire for your car, and then you re-tune the entire chassis to take full advantage of the newfound grip. Let’s start with the tires.
Upgrading from Michelin Pilot Sports to Pilot Sport Cup 2 tires represents a serious performance and technology leap. The GT350R has used wider-section versions of this tire from the start (305 front/315 rear to the GT350’s 295/305), and the tires look rather similar. Both feature a broad, featureless outer shoulder for lateral bite, three shallow tread channels (the old Pilot Sports had four deeper ones), and large tread blocks. The tread-wear rating is 180, down from 300 for the old Pilot Sports. We’re told the new ones should last 12,000–15,000 miles (19,000-24,000 km) on the street (track days will shorten their life—a lot). The tread compound differs from that of the GT350R. To make it more street-friendly in the “shoulder seasons” (this is a summer tire), its “glass-transition temperature” (when rubber turns from grippy to hockey-puck slippy) is lower—but never drive on them under a frost/freeze warning. The more angular sidewall profile shape and construction contributes to the way the tire performs in lateral maneuvers (and serves to protect the rims from brushes with the curb). The scant shallow treads suggest these tires would be a handful in the rain, but Mustang chief program engineer Carl Widmann swears they meet the same wet-traction standards as the old one. Ford Performance-engineered tires wear an “FP” mark on the sidewalls that buyers need to insist on when replacing their tires. Frequently. (Tire Rack price: $1,822.74 USD for a set.)
Working up from the tires, the spring rates are stiffened 10 percent in front, where the anti-roll bar remains unchanged. In back the spring rates soften by 6 percent to coordinate with a larger, stiffer, hollow rear bar (now 24mm, up from 22mm). The MagneRide shocks are completely retuned to suit these changes and the new tires, and also to take advantage of improvements in the software and algorithms that have simply come with the march of progress.
One more chassis enhancement: The electronic programming of the stout Brembo brake system is totally recalibrated. It can now dynamically alter the proportioning from front to rear and side to side to a greater extent than it used to, which is said to improve the way the car feels when braking into a corner.
The Shelby GT350’s one big non-chassis-related update is to aerodynamics. To help boost the confidence of drivers whose tracks include longer straights and higher-speed bends and sweepers, front and rear aero-mods help to better settle the car at speed. In front, the main upper grille opening is blanked off more. They basically realized the cooling pack didn’t need as much air as it was getting, and the surplus air was just getting trapped under the hood and causing lift. There is still a hint of front-end lift at speed, but less than before. In back there’s a new “s’wing”—a hybrid spoiler/wing that leverages lessons learned on the GT500 program in a rolling ground-plane wind tunnel in North Carolina. Think of it as a spoiler with two big vents that allow the highest velocity air to slip straight through, reducing drag, while the rest rides the s’wing surface to develop positive downforce.
This basic s’wing helps plant the rear quite nicely, but if you want it planted with deep roots on the fastest tracks, you’ll spend another $850 USD for a handling package. It includes an aggressive Gurney flap that bolts to the stock s’wing via four simple torx-head screws (removing this gas-mileage killer is worth a couple highway mpg on the drive home from the track). Also included are a pair of front strut camber plates that allow for easy swapping between tire-preserving street alignment and a max-cornering negative-camber track setup.
Naturally, the cars we were invited to drive on the 1.5-mile (2.4-km) Champion Motor Speedway course at suburban Detroit’s M1 Concourse had all the performance goodies dialed up to max-attack mode. I drew first drive in a white-with-blue-stripes GT350 on a 50-degree morning. Sure enough, until these tires warmed up, I experienced entry understeer and/or power oversteer in several of the track’s 11 turns. After about a lap and a half, though, they warmed up and started biting harder and harder with nary a stomach-knotting squirm or wiggle. This did encourage me to charge deeper into each turn, and even to roll onto the gas more aggressively on the exits.
I’d be lying if I claimed to detect the savvier brake proportioning, but my confidence did indeed build quickly on what is still a fairly unfamiliar new track to me, so perhaps Widmann and team can hoist the “mission accomplished” banner on that customer wish. One thing that happily remains utterly unchanged is the frenetic sound of this uniquely big-lunged flat-plane V-8 in sport-exhaust mode. Without any of the fourth-order “wuffle” that traditional V-8s make, the resulting sound is akin to a pair of Suzuki Hayabusa motors shouting in unison down a sewer pipe. Long may this glorious sound echo down these stainless, sport-tuned sewer pipes.
The GT350 is on sale now starting at $61,435 USD—just $3,295 USD more than the 2018 model, and according to Tire Rack, $449.28 USD of that is the tires.
|2019 Ford Mustang Shelby GT350|
|VEHICLE LAYOUT||Front-engine, RWD, 2-pass, 2-door coupe|
|ENGINE||5.2L/526-hp/429-lb-ft DOHC 32-valve V-8|
|CURB WEIGHT||3,750-3,800 lb (mfr)|
|LENGTH X WIDTH X HEIGHT||188.9 x 75.9 x 54.2 in|
|0-60 MPH||4.1 sec (MT est)|
|EPA CITY/HWY/COMB FUEL ECON||14/21/16 mpg|
|ENERGY CONSUMPTION, CITY/HWY||241/160 kW-hrs/100 miles|
|CO2 EMISSIONS, COMB||1.18 lb/mile|
|ON SALE IN U.S.||Currently|