And now, for something totally different…2015 Polaris Slingshot Review
Imagine designing a vehicle from the ground up – starting with a clean sheet of paper and no preconceived notions – and being able to apply proven technologies in bold new ways.
Your assignment: create something that is off the page and owes nothing — or at least very little — to conventional wisdom. Given the resources and expertise now at the disposal of Polaris Industries, you could come up with the 2015 Polaris Slingshot.
We were invited to the Polaris Research and Development Center in Wyoming, Minn., to take a first ride and find out what that kind of imaginative engineering can produce.
Start with its three-point stance — ok, there are other vehicles with that, even with the two wheels out front, one to the rear configuration. That’s what the Can-Am Spyder has today and what the Morgan three-wheelers from the U.K. had. But apart from those general similarities, the Slingshot is something else again.
Unlike the Spyder, which puts the passengers atop the machine’s 29” seat height over the engine and drivetrain in tandem, the Slingshot puts the passengers down in the vehicle side-by-side.
That makes having a conversation easier, even with helmets on and without communication gear. With 5 inches of ground clearance, the Slingshot is low-slung and brings its center of gravity close to the ground. Unlike the Spyder’s snowmobile-like frontal view, the Slingshot has a lower, wider more aggressive automotive front with styling cues Enzo Ferrari could admire.
Its 77.6-inch wide front stance is significantly wider than the Spyder, which is 59.3 inches. That, along with its low center of gravity in combination with purpose-built Slingshot branded low profile radial tires, inspires confidence in the corners.
In fact, those chassis characteristics in combination with electronic stability control, traction control and anti-lock brakes make for a driving experience that might be more akin to a Formula 1 car than recreational vehicle — not that anybody’s ever been crazy enough to let me drive their Formula 1 car. For licensing purposes, the Slingshot is considered a motorcycle, and requires a cycle operator’s license for the driver.
Unlike the Spyder’s more motorcycle-like handlebars and cockpit, the Slingshot again is more akin to a car with a steering wheel and pedals to work the throttle, clutch and brakes. The five speed synchromesh manual transmission has a short shift lever that is close at hand and shifts with quick, short throws from one ratio to another.
Each shift is smooth and reverse is easy to find. The clutch is a dry, single-plate, hydraulically activated unit with a light feel and smooth, progressive engagement. Asked about an automatic transmission in the future, Polaris staff members were non-committal. But it seems a logical progression if the manual transmission version does well in sales. From the transmission, power goes through a jackshaft that carries the drive pulley for the final drive, which is a 36 mm x 147T carbon fiber reinforced toothed belt.
Perhaps the trump card that sets the Slingshot apart from anything in its market segment is the power plant. An all-aluminum 2.4 liter General Motors EcoTec DOHC in-line four cylinder gas engine (91+ octane recommended) with direct fuel injection, four valves per cylinder and variable valve timing makes a whopping 173 crankshaft horsepower at 6200 RPM and 166 lb/fts of torque at 4700 RPM. To preserve the engine against over-zealous throttle use, there is a rev-limiter at 7000 RPM. To get at the power-plant and all the equipment that goes with it, there is a reverse-tilt hood.
With that much power on tap in a vehicle that weighs only 1,725 lb. for the base model to 1,743 lb. for the ST model fueled up and ready to ride, you might expect some tractability problems. Not so. Even under hard acceleration, the Slingshot powers away in a straight, predictable line on the straightaways and in a smooth, precise arc in corners.
Despite its power-to-weight ratio of about only 10 pounds per horsepower, the electronic stability control, traction control system, and ABS disc brakes intervene so subtly the machine stays keyed into the road surface, even under deliberately hot corner entries, exits and very hard braking. The suspension makes for a surprisingly smooth ride, but with good road feel and level cornering.
To achieve that stability, Polaris started with a high-strength steel space frame chassis. The sport-tuned suspension includes automotive type double-wishbone forged aluminum swing arm front suspension with coil spring over gas-filled shocks. Flat, wallow-free cornering is achieved with the help of a hefty anti-sway bar.
Rear suspension is by a large coil spring over gas-filled mono-shock between the top of the rear space frame member and a stout single-side aluminum swing arm. Topping the chassis is a pair of forged aluminum roll bars above each seat which Polaris engineers state can handle five times the vehicle’s weight.
The anti-lock brakes chomp on 298mm ventilated discs front and rear. Putting the stopping and starting power to the ground are purpose-built, Slingshot branded Kenda 799 radial tires; 205/50 R17 are mounted on eight-spoke cast rims on the front of the basic Slingshot, 225/45 R18 on ten spoke forged rims on the top-of-the-line Slingshot SL. Rear tires are 265/35 R18 on the basic Slingshot and 255/35 R20 on the SL.
The cockpit has an automotive-style dash with analog speedometer and a tachometer, turn signal/high-low headlight beam stalk, which incorporates the cruise control. Integrated in the instrument faces are the usual automotive-style warning lights and an LCD for additional information. The horn button is in the center of the steering wheel, auto-style. In the SL model, there is a media center with 4.3” LCD screen, backup camera, USB input port, 6 speaker audio system and Bluetooth integration. All of which, according to Polaris product engineering staff, are impervious to the weather, as evidenced by many encounters with a power washer.
The seats look hard, angular and probably uncomfortable, but turned out to be remarkably soft and offering good support and comfort. There is no upholstery on the seats per-se; the seats have a skin that is bonded to the cushioning, making them seamless and waterproof.
They can take the weather if the vehicle is caught out in the rain and can be cleaned with a hose, if need be. Three-point automotive-style seat belt and shoulder harnesses secure driver and passenger in the doorless and roofless Slingshot.
Storage space in the cockpit is provided by a large, lockable bin concealed behind each seat that folds forward and a moderately sized lockable glove compartment down in the side of the console. The bins are large enough to hold a full face helmet each, plus a little more.
Large LED taillights help make the low-profile Slingshot visible to other drivers and twin projector beam headlights and twin projector accessory lights light the way. Dual racing-style rear-view mirrors mount on long stalks that tended to vibrate a bit at times but overall provided good rear-ward visibility. That said, the rear-view camera in the media package option would probably be a good thing.
The base model Slingshot does not include a windshield, but a blade windshield or “double bubble” a-la Batmobile windshield system can be optioned on. The SL comes standard with a blade windshield. Other options include cockpit cover, full vehicle cover, dust cover, interior lighting kit, premium wheels and tires and smartphone mount.
The body is constructed of polymer with Titanium Metallic as the standard color for the base Slingshot and Slingshot Red Pearl and black the standard color for the SL. No other color options are available at this point. Backing it all up is a two-year factory warranty.
On the road and track
Control from the steering wheel is light and precise through the use of Polaris Electric Power Assisted Steering (EPAS) and a rack and pinion system. To allow the machine to change direction as quick as a ricochet at low to moderate speeds but with smooth, predictable control at high speed, the steering assist system is speed sensitive. There are only 3.2 turns of the steering wheel, lock-to-lock.
As a critical element in both product performance and safety, Polaris engineers explained they spent an extraordinary amount of time on the test track perfecting the orchestration of steering action, chassis and suspension interaction and electronic stability/traction control to arrive at the present state of handling capability. The work has paid off.
Riding with Polaris Tech Developer, Shane Marko, I had the opportunity to have a taste of the Slingshot in uninhibited mode with an expert at the controls. In tortuous “J-turn” maneuvers from interstate speed, diminishing radius high speed cornering tests and deliberate attempts to make the Slingshot spin out with full-throttle sudden wheel cuts, the Slingshot never lofted the inside wheel. It also never displayed minimal tire slip that quickly corrected and did not spin out. Since the traction control can be turned off, which Polaris staff does not recommend for normal operating conditions, we had to see how it did in that mode.
“I’ve been working on this project for a long time and I’ve done just about everything with it you can imagine and it’s never had a problem with maintaining control,” he said as he increased the throttle in a decreasing radius turn test.
As he spoke the g-forces kept rising and my counter-lean into the corner kept getting more acute, yet the Slingshot kept holding fast, until enough power was getting to the rear wheel to finally overcome the grip of that big Slingshot tire on the rear.
Predictably, with the traction control turned off, the engine could easily break the rear tire loose and tire-scorching wheel spin in corners and in straight-line acceleration was easy and on-demand. It was exciting, to be sure, but in my opinion, the Slingshot’s performance potential for the average consumer is most impressive with traction control engaged.
Switching up from passenger to driver, with the three point seat belt buckled up and helmet on, I had the chance to get the feel of the wheel and the pedal.
Direction changes are cat-quick and flat; the sway bar keeps the Slingshot level and tires in full contact with the pavement. As speed increases, the speed-sensitive electric power assist rack and pinion steering provides precise, quick lane-change maneuvers with no tendency toward oversteer or understeer. Holding a line through corners is easy, even in decreasing radius corners at highway speed.
Acceleration is available any way you like it; through the gears as smooth and easy as the family car or speed-shifting quarter-mile hard. While we were free to thrash the Slingshot pretty much any way we wanted, we didn’t do timed quarter-mile runs and Polaris doesn’t publish any figures on it, but my seat-of-the-pants-o-meter says the Slingshot could turn in some impressive ETs and terminal speeds right off the showroom floor.
Panic stopping maneuvers on the test track from highway speed brought on the ABS brakes with no pull, fade or nose-dive. Maneuvers with combined cornering and braking, such as the J-turn—which roughly replicates the evasive action one might take when a deer runs out into the roadway, for example—can be accomplished with no sense of imminent loss of control. After rough-housing the vehicle on the test track and getting to know the Slingshot’s performance at the extreme, it was time to take it out on the open road.
As you might expect, with a sport-tuned suspension designed to handle extreme cornering, acceleration and braking forces, the ride on some of the rougher sections of Minnesota’s blacktop secondary roads seemed a little stiff.
Of course, that may be a common situation with any new vehicle that diminishes somewhat over time. On the better pavement of state highways, the ride was smoother and quieter, though engine drone in the cockpit does become noticeable though not enough to drown out conversation.
Noticeable engine heat also seemed to accumulate a bit down inside the open cockpit as the weather conditions warmed up, similar to how engine heat can be drawn up behind a full fairing.
Polaris doesn’t publish any fuel economy figures at this time, and we didn’t do enough regular road driving to get an assessment on our own, so it’s unclear how far you can go on the 9.77 gallon (37.1 L) fuel tank. And, of course, that depends on how hard you press the pedal.
After a day of thrashing the Slingshot and Slingshot SL on the test track and getting it out on the road, it seemed that the question really isn’t whether it can be competitive in its market segment, but rather, whether it will redefine it.
