November 19, 2013 8:30 PM
To be clear, I did not drive the Nissan BladeGlider concept. What I did drive was Nissan's proof-of-concept behind the BladeGlider: a test mule mocked up with a similar narrow-front-track suspension arrangement. It's meant to demonstrate the virtues of this unconventional setup to Nissan engineers and executives, and a handful of journalists.
Let me be clear on another point: This car changes everything—forget what you thought you knew about sports car handling.
For example: At Nissan's Arizona proving grounds, I'm driving a conventional Ariel Atom for the second time. It feels skittish after driving the narrow-front-track prototype, and I'm cornering much slower. Coming out of the tight left-hand turn on the test course, I can actually see and feel that the inside tire isn't providing much grip, which is why the car won't respond as eagerly as I want. But here's the crazy thing: Without having driven the Nissan narrow-front-track prototype, I would never have thought this was a problem. It was just a normal part of a car's cornering limits—even a crazy performance car. After just a few minutes behind the wheel of the proof-of-concept prototype, I realize I have to re-wire my brain to understand what's possible.
Conventional wisdom says that a wide track is essential for stability, and that putting as much tire as possible at all four corners results in the best handling and grip. But as Bowlby is about to show me, that's not always the case. He says that the key behind the narrow-front-track concept is balancing the tires to the weight of the car.
To demonstrate, in front of me are two Ariel Atoms, an open wheel track-day car with an exposed frame, open cockpit, and midmounted 230-hp engine. One is totally stock. The other has the front track narrowed from 63 inches to a skinny 39.4 (the same as in the concept car). In place of the side-by-side stock seats, the test mule has a single, center-mounted racing bucket. The radiators have been moved rearward to help shift the weight distribution to about 29:71 front to rear, compared with 37:63 in the stock car. Bowlby's team also added an adjustable rear antiroll bar. And, of course, they changed the tires—from 195/50R-15 in front and 205/55R-15 in rear to 155/50R-15 front and 245/40R17 rear. The total contact patch for both cars is the same, but the altered car has all-season Continental ContiProContact rubber because they couldn't find high-performance tires in such a narrow size.
Bowlby is careful to point out that the demonstration car has nothing to do with the BladeGlider, or the production car that it will spawn (or the Ariel, for that matter). It's merely a way to demonstrate the ride and handling of a narrow-front-track car.
The altered car looks so odd compared with anything else on four wheels, I can't wrap my head around the idea. Bowlby suggests I drive the cars before any explanation colors my initial impression. I start in the conventional car. Nissan has a small course of cones set up on a vast swath of pavement. I take a few laps to warm up, slowly increasing my speed. On lap three, I spin in a sweeping left corner after suddenly lifting off the gas. The Atom is a serious car—highly responsive but also very sensitive to the driver's inputs. Get a little too ambitious, and you can get into trouble.
Baseline impressions completed, I hop into the narrow-front-track car (unfortunately, Nissan doesn't yet have a better name for this idea). It takes a couple of laps to get used to the fact that the car is much wider at the rear, but I avoid the embarrassment of clipping any cones. After a hard acceleration to about 100 mph, I hammer on the brakes. The altered car is obviously much more stable under deceleration. There are no antilock brakes on either car, but it's easy to modulate the pedal in the altered prototype right at the edge of the tires' grip. I spin again on the third lap, but this time nearly on purpose, after several loops around a circular skidpad trying to drift the back end of the car.
The difference between the two cars is stunning. It's hard to believe they share so much hardware. In the standard car, driving at the limit is a tricky balancing act between understeer (which is when the front end become unresponsive) and oversteer (which is when the back starts to come around on you). Nobody would ever suggest that a stock Ariel Atom is unresponsive, but the altered car drives like it's hard-wired into your brain. After just five laps around the improvised course, I'm converted.
Even with that firsthand experience, I can't wrap my brain around why the narrow-front-track works so well. It still looks unnatural, though the physics behind it are sound. "Form following function," is a phrase that peppers Bowlby's explanation. The narrow front drastically reduces drag, which leads to better energy efficiency. And with all the weight and tires shifted toward the rear, the car can accelerate almost as well as a four-wheel-drive car.
As for the handling, the narrow front track actually makes plenty of sense when you look at it closely. When a conventional car turns around a corner, the outside front tire takes a path that is much wider than the inside tire. Most cars use a trick known as Ackerman geometry to solve this problem and turn the inside tire more sharply. When you reduce the front track to 40 inches or less, the front tires essentially follow the same path. That means there's no need for Ackerman steering, and because the tires also share cornering loads evenly, tricks to balance out the grip side-to-side with a geometry setup are also unnecessary. The altered prototype I'm driving has zero toe and camber on the front tires. As an added benefit, the tires wear more evenly.
But with skinny front tires and so much weight on the rear, how does the car actually turn? It seems counterintuitive, but the light front end makes the car more responsive. With the center of gravity shifted rearward, there's very little inertia involved in going around a corner. Or, as Bowlby puts it, you're not dragging the center of gravity through a corner. It's somewhat akin to if you lay a sledgehammer on a table—the light end moves easily while the heavy head acts as a pivot point.
Surely, though, the weakness of the narrow front track is bumps, right? Actually, a natural assumption is wrong again. The light front allows for softer springs and less roll stiffness, which give the car more compliance over rough surfaces. Conventional cars adjust to the road from four points, so if one wheel goes over a bump it tries to twist the rest of the suspension in response. The narrow front track is more like a three-legged bar stool: The tires are always in the same plane so it's never uneven and never has to fight against itself. It's a tough idea to grasp, but Bowlby says the key is balancing the weight, grip, and roll stiffness. "Strangely enough, the triangular layout gives you a very consistent and coherent balance in the car. And that was a very unexpected discovery."
Not even Bowlby knew that a narrow-front-track car would be a success. "I don't think that anybody put their hand on their heart and said this is going to work," he says. But when Nissan built the DeltaWing racer, all the drivers kept saying it was the most fun car they'd ever driven. That led to further development with the ZEOD and what will eventually be the production version of the BladeGlider.
The BladeGlider's electric powertrain makes it easy to achieve the rear weight bias needed for the narrow-front-track setup. The concept car uses two motors mounted directly in the hub of each rear wheel, and with 75 percent of the weight on the rear axle, it's safe to assume that most of the batteries are mounted in the aft section. The concept car's tires are even more extreme than the prototype's, with 100/80-17 rubber in front—essentially a motorcycle-tire dimension—and 285/35-19 dimensions in the rear.
Back in Arizona, Bowlby mentions that the added benefit of the narrow-front-track arrangement is that having all the weight and aerodynamic drag at the back of the car makes it naturally stable. Plus, he says, the altered suspension gives the test prototype 10 percent more grip than the stock version, even with the all-seasons mounted in front. As I take on more laps in the prototype, I'm amazed at how stable it remains, right up to the limit. The stock Ariel is thrilling, of course, but you're always reacting to the shifting loads through accelerating, cornering, and braking. The narrow-front-track car, in contrast, makes me feel like my reflexes are twice as fast. I've never driven a car that's so balanced.
Nissan's statements up to this point have been clear: There will be a production derivative of the BladeGlider. And not just a few copies for the ultrarich, as is the case with the Juke R, but an actual car you can buy in the showroom. In speaking with Nissan executive Andy Palmer before the Tokyo Motor Show, he said that while he can't be too specific, it usually takes about three years for a car to progress from the concept to production stage. He also made it clear that the road-going BladeGlider will be built in numbers that make it accessible to anybody who wants and can afford one. Of course, both the cost and sticker price are pretty hard to figure out at this point. No carmaker has been as bold as Nissan in committing to such an unorthodox idea.
The BladeGlider concept's debut at the Tokyo Motor Show will find plenty of detractors, and with some reason. After all, nobody has even seen anything like this on the road. It's still hard to for me to understand how the car works from just looking at it. But having driven the proof myself, there's no doubt that anybody who drives the car will quickly convert from skepticism to believing that this is how every sports car should be made.
Let me be clear on another point: This car changes everything—forget what you thought you knew about sports car handling.
For example: At Nissan's Arizona proving grounds, I'm driving a conventional Ariel Atom for the second time. It feels skittish after driving the narrow-front-track prototype, and I'm cornering much slower. Coming out of the tight left-hand turn on the test course, I can actually see and feel that the inside tire isn't providing much grip, which is why the car won't respond as eagerly as I want. But here's the crazy thing: Without having driven the Nissan narrow-front-track prototype, I would never have thought this was a problem. It was just a normal part of a car's cornering limits—even a crazy performance car. After just a few minutes behind the wheel of the proof-of-concept prototype, I realize I have to re-wire my brain to understand what's possible.
The Story So Far
I'm getting a little ahead in the story here. I'm out in Arizona because of Ben Bowlby, who's official title with Nissan is director of motorsports innovation. He's the mastermind behind the narrow front track concept, which began as the DeltaWing concept for IndyCar and was eventually picked up by Nissan for an experimental run at the 24 Hours of Le Mans. Nissan parted ways with the DeltaWing name when racing mogul Don Panoz bought the rights to it, but the company brought Bowlby on board and continues to develop the narrow-front-track idea with the ZEOD RC, which will return to Le Mans in 2014.Conventional wisdom says that a wide track is essential for stability, and that putting as much tire as possible at all four corners results in the best handling and grip. But as Bowlby is about to show me, that's not always the case. He says that the key behind the narrow-front-track concept is balancing the tires to the weight of the car.
To demonstrate, in front of me are two Ariel Atoms, an open wheel track-day car with an exposed frame, open cockpit, and midmounted 230-hp engine. One is totally stock. The other has the front track narrowed from 63 inches to a skinny 39.4 (the same as in the concept car). In place of the side-by-side stock seats, the test mule has a single, center-mounted racing bucket. The radiators have been moved rearward to help shift the weight distribution to about 29:71 front to rear, compared with 37:63 in the stock car. Bowlby's team also added an adjustable rear antiroll bar. And, of course, they changed the tires—from 195/50R-15 in front and 205/55R-15 in rear to 155/50R-15 front and 245/40R17 rear. The total contact patch for both cars is the same, but the altered car has all-season Continental ContiProContact rubber because they couldn't find high-performance tires in such a narrow size.
Bowlby is careful to point out that the demonstration car has nothing to do with the BladeGlider, or the production car that it will spawn (or the Ariel, for that matter). It's merely a way to demonstrate the ride and handling of a narrow-front-track car.
The altered car looks so odd compared with anything else on four wheels, I can't wrap my head around the idea. Bowlby suggests I drive the cars before any explanation colors my initial impression. I start in the conventional car. Nissan has a small course of cones set up on a vast swath of pavement. I take a few laps to warm up, slowly increasing my speed. On lap three, I spin in a sweeping left corner after suddenly lifting off the gas. The Atom is a serious car—highly responsive but also very sensitive to the driver's inputs. Get a little too ambitious, and you can get into trouble.
Baseline impressions completed, I hop into the narrow-front-track car (unfortunately, Nissan doesn't yet have a better name for this idea). It takes a couple of laps to get used to the fact that the car is much wider at the rear, but I avoid the embarrassment of clipping any cones. After a hard acceleration to about 100 mph, I hammer on the brakes. The altered car is obviously much more stable under deceleration. There are no antilock brakes on either car, but it's easy to modulate the pedal in the altered prototype right at the edge of the tires' grip. I spin again on the third lap, but this time nearly on purpose, after several loops around a circular skidpad trying to drift the back end of the car.
The difference between the two cars is stunning. It's hard to believe they share so much hardware. In the standard car, driving at the limit is a tricky balancing act between understeer (which is when the front end become unresponsive) and oversteer (which is when the back starts to come around on you). Nobody would ever suggest that a stock Ariel Atom is unresponsive, but the altered car drives like it's hard-wired into your brain. After just five laps around the improvised course, I'm converted.
But How Does It Work?
Even with that firsthand experience, I can't wrap my brain around why the narrow-front-track works so well. It still looks unnatural, though the physics behind it are sound. "Form following function," is a phrase that peppers Bowlby's explanation. The narrow front drastically reduces drag, which leads to better energy efficiency. And with all the weight and tires shifted toward the rear, the car can accelerate almost as well as a four-wheel-drive car.
As for the handling, the narrow front track actually makes plenty of sense when you look at it closely. When a conventional car turns around a corner, the outside front tire takes a path that is much wider than the inside tire. Most cars use a trick known as Ackerman geometry to solve this problem and turn the inside tire more sharply. When you reduce the front track to 40 inches or less, the front tires essentially follow the same path. That means there's no need for Ackerman steering, and because the tires also share cornering loads evenly, tricks to balance out the grip side-to-side with a geometry setup are also unnecessary. The altered prototype I'm driving has zero toe and camber on the front tires. As an added benefit, the tires wear more evenly.
But with skinny front tires and so much weight on the rear, how does the car actually turn? It seems counterintuitive, but the light front end makes the car more responsive. With the center of gravity shifted rearward, there's very little inertia involved in going around a corner. Or, as Bowlby puts it, you're not dragging the center of gravity through a corner. It's somewhat akin to if you lay a sledgehammer on a table—the light end moves easily while the heavy head acts as a pivot point.
Surely, though, the weakness of the narrow front track is bumps, right? Actually, a natural assumption is wrong again. The light front allows for softer springs and less roll stiffness, which give the car more compliance over rough surfaces. Conventional cars adjust to the road from four points, so if one wheel goes over a bump it tries to twist the rest of the suspension in response. The narrow front track is more like a three-legged bar stool: The tires are always in the same plane so it's never uneven and never has to fight against itself. It's a tough idea to grasp, but Bowlby says the key is balancing the weight, grip, and roll stiffness. "Strangely enough, the triangular layout gives you a very consistent and coherent balance in the car. And that was a very unexpected discovery."
From the Track to the Street
Not even Bowlby knew that a narrow-front-track car would be a success. "I don't think that anybody put their hand on their heart and said this is going to work," he says. But when Nissan built the DeltaWing racer, all the drivers kept saying it was the most fun car they'd ever driven. That led to further development with the ZEOD and what will eventually be the production version of the BladeGlider.
The BladeGlider's electric powertrain makes it easy to achieve the rear weight bias needed for the narrow-front-track setup. The concept car uses two motors mounted directly in the hub of each rear wheel, and with 75 percent of the weight on the rear axle, it's safe to assume that most of the batteries are mounted in the aft section. The concept car's tires are even more extreme than the prototype's, with 100/80-17 rubber in front—essentially a motorcycle-tire dimension—and 285/35-19 dimensions in the rear.
Back in Arizona, Bowlby mentions that the added benefit of the narrow-front-track arrangement is that having all the weight and aerodynamic drag at the back of the car makes it naturally stable. Plus, he says, the altered suspension gives the test prototype 10 percent more grip than the stock version, even with the all-seasons mounted in front. As I take on more laps in the prototype, I'm amazed at how stable it remains, right up to the limit. The stock Ariel is thrilling, of course, but you're always reacting to the shifting loads through accelerating, cornering, and braking. The narrow-front-track car, in contrast, makes me feel like my reflexes are twice as fast. I've never driven a car that's so balanced.
Let the Waiting Begin
Nissan's statements up to this point have been clear: There will be a production derivative of the BladeGlider. And not just a few copies for the ultrarich, as is the case with the Juke R, but an actual car you can buy in the showroom. In speaking with Nissan executive Andy Palmer before the Tokyo Motor Show, he said that while he can't be too specific, it usually takes about three years for a car to progress from the concept to production stage. He also made it clear that the road-going BladeGlider will be built in numbers that make it accessible to anybody who wants and can afford one. Of course, both the cost and sticker price are pretty hard to figure out at this point. No carmaker has been as bold as Nissan in committing to such an unorthodox idea.
The BladeGlider concept's debut at the Tokyo Motor Show will find plenty of detractors, and with some reason. After all, nobody has even seen anything like this on the road. It's still hard to for me to understand how the car works from just looking at it. But having driven the proof myself, there's no doubt that anybody who drives the car will quickly convert from skepticism to believing that this is how every sports car should be made.
Read more: EXCLUSIVE: (Sort of) Driving the Nissan BladeGlider Concept - Popular Mechanics
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