The difference between the Shelby GT350 and GT350R comes down to one letter and one purpose: The GT350R is meant to be a track beast. In 1965, the first year of the Shelby GT350’s production, 35 were labeled as GT350R. The R stood for race-spec and designated the cars that complied to SCCA rules and were ready for competition. For three years, the GT350R was B-Production Champion.
In 2016, the Shelby GT350 re-emerged, and with it the 350R. Though it had been an optional package sporadically starting in 2011, this has been the longest run of the 350 and 350R since its original production run from 1965-1969.
Though many think of GT500 first, the GT350 was actually Carroll Shelby’s first contribution to Mustang’s history, though certainly not the last. The GT350 has several key differences from the GT500 and has been available for fewer years.
Through the S550 era, a few changes have been made to the GT350 overtime to keep it competitive. In 2019, the MagneRide suspension system was recalibrated with new springs and improved damping. The tires were improved, giving the GT350 more grip. It also has gained some additional amenities for improved comfort. Overall, the aesthetic has stayed the same though.
Speed Difference Between Shelby GT350 and GT350R
The GT350 and 350R are both equipped with the Voodoo Coyote variant. It’s a flat-plane crankshaft engine that creates a truly astonishing amount of horsepower. At 526 hp and 429 lb-ft of torque, it’s an impressive engine. Despite being equipped with the same engine though, the GT350R performs better on the track.
Motortrend tested the GT350 and 350R and found that there was a difference in track time. Though that difference might not be much, in a race, where winning comes down to fractions of seconds, every little bit counts.
GT350 vs GT350R
|Quarter Mile Time
Car and Driver conducted a similar test, though they clocked the GT350 at 4.2 seconds to reach 60mph. Despite primarily being the same car from a mechanical viewpoint, the R is consistently faster.
Mechanical Additions to Shelby GT350R
The R offers heavy-duty springs which result in a stiffer feeling suspension. Though a stiffer suspension may be less comfortable for day-to-day driving, it helps a car handle the enormous g-forces generated on a track. The stiffer suspension also helps with cornering, particularly at high speeds.
Additionally, the R comes standard with coolers for the engine oil, differential, and transmission fluid. Keeping these fluids cool despite the additional heat generated by heavy use helps to keep all of the parts functioning correctly. As oil gets overheated it becomes more viscous and thus less able to keep all the components of the engine properly lubricated. Though most cars can keep their oil at the right viscosity without fluid specific coolers, that isn’t true of performance vehicles. Particularly when they’re running their engines hard.
Carbon Fiber Wheels
“Float like a butterfly” is good advice, especially when you’re trying to get a car that’s already fast to somehow go even faster. The Shelby 350R floats on carbon fiber wheels instead of the standard aluminum. A savings of nearly 60 pounds that accounts for nearly half of the 130 pounds that have been trimmed from the GT350’s already lean form to make the GT350R.
The benefits of carbon fiber wheels can’t be measured in pounds alone though. Rotational inertia is also improved by having lighter wheels. For wheels, shaving a pound off of the rotating mass is the equivalent of shaving a little over a pound and a half of static mass. This means that the overall effect of reducing the wheel weight by 60 pounds ends up equaling a savings of close to 90 pounds.
Lighter wheels have additional benefits. When the car spends less energy to move the wheels, it’s easier to steer which improves response time.
Carbon fiber wheels are a big deal. Each one on the aftermarket costs roughly $4,000, so if you are considering buying a Shelby 350 and carbon fiber wheels, you’d be foolish to not get the R package. The 2016 Shelby GT350R was the first car to be mass-produced with carbon fiber wheels and not coincidentally won Road and Track’s “Performance Car of the Year” award.
Carbon Fiber Grille Opening and Wing
Not enough has been said about the GT350's grille design. Even the 2016 GT350 and GT350R came with a carbon fiber grille opening, but serious improvements have been made to the grille design since then. The GT350 and 350R both come with a carbon fiber grille opening, but for 2019 both also have a smaller opening that helps to cool air as it enters the car. By keeping the grille opening small, not only is the air-cooled but also lift is reduced.
The carbon fiber wing is unique to the 350R and is designed to be totally functional. The larger splitter and rear wing combo were designed not just to reduce lift, but also to create downforce.
Using carbon fiber helps to trim a little more weight from the 350’s frame and ultimately adds a lot to the performance orientation of its look.
The GT350R’s carbon fiber wheels demanded a more awesome tire, and Ford found one. The GT350 came with Super Sport tires while the 350R was given Sport Cup 2 Summer-Only tires. These tires are street-legal slicks, designed for track days and utterly undone by a stormy day. The tires are perhaps the greatest indicator that the R is meant to be a track beast, even at the expense of daily driving capabilities. These extra-grippy tires are performance-ready, fortified with a stiff sidewall that is designed to carve corners and create responsive handling but that may also make riding along a bumpy road a bit of a challenge.
The Michelin tires were designed exclusively for the GT350R, and they have a special compound and tread pattern. Though these tires were intended to be used for the GT350R, in 2019, Ford allowed the GT350 to also come equipped with these tires. The new wheels for the 2019 GT350 were 19" and aluminum rather than carbon fiber though. Not a surprise, given the price difference between the two cars.
The GT350 and GT350R were so incredible on relaunch that there haven't needed to be significant performance improvements through the years. Instead, what Ford has improved are the various amenities that the GT350 siblings can come with. In 2019, the most significant changes were made. The 2019 GT350 upgraded the Recaro race seats, giving them power adjust. Harman provided a twelve-speaker sound system, for those who want to hear music over their flat-plane engine. Naturally, they also upgraded the infotainment system to the significantly preferable SYNC 3.
2020 didn't see many massive updates, but if you were holding out for wifi connectivity, then 2020 is finally your year. As of 2020 GT350s come with FordPass Connect. This small change allows the GT350 to serve as a hotspot and get traffic updates.
Is the R Package for You?
Unfortunately, a lot of the difference in weight between the GT350 and GT350R comes from deleting some features you might care a little more about. The R doesn’t come with air conditioning, an audio system, a rear seat, a rear-view camera, a tire inflator, floor mats, or SYNC 3. You can add most of this back with the “electronics” package, but with it will come some weight as well.
The GT350R aims to cut weight in any way it can, and with that, it should be expected that some comfort features might be lost. Though the deletion of these features might make some believe that the GT350R isn't a good fit for them, if you were planning to get carbon fiber wheels anyway, honestly, it’s fiscally irresponsible not to just get the Shelby GT350R. The wheels alone are worth $16,000. However, if you want to try to use the 350R as your daily driver, you’ll need to add some additional options packages to make it comfortable, and really hope that you don’t accidentally break the wheels.
But if you’re thinking purely of performance, it’s hard to think of a reason not to go for the Shelby GT350R.
Sources: Balancing Rotating Machinery with Wolfram SystemModeler, Wolfram Research | Does the Shelby GT350R Make More Power Than the Regular GT350?, MotorTrend | Tested: 2020 Ford Mustang Shelby GT350R Leaves a Lasting Impression, Car and Driver | Can the 2016 Shelby Mustang GT350R Live Up to the Legendary Original?, Road and Track | Image Credit: Ford | Ford Performance