Nissan GT-R LM NISMO “Racing is a Battle. Our Weapon is Innovation.”

Nisan at Le Mans 2015: Scrutineering Session

 

 

Le Mans, France (Thursday 11 June 2015): The world has never seen a racing car quite like the GT-R LM NISMO. Radical in concept and bold in execution, it was created at the point where imagination, knowledge and courage intersect. Its mission is to explore new ideas, to pioneer an uncharted route toward unprecedented speed and efficiency and, ultimately, outright victory in the greatest motor race of them all, the Le Mans 24 Hours.

PrintNo one has ever attempted to win Le Mans outright with a front-engined, front-wheel drive racing car. To some, the very notion of it seems preposterous when history points to cars with precisely the opposite configuration being the accepted route to glory. Yet if you’re prepared to cast convention aside and look to science, the rule book and the race itself, compelling new answers can be found. Nissan’s is the GT-R LM NISMO.

By adopting a radical front-engined, front-wheel drive layout, the GT-R LM NISMO literally turns the rulebook on its head, finding creative freedom in the same technical regulations that have evolved to restrict the performance of the conventional LM P1 contenders. Combined with a hybrid propulsion system that mates a powerful, super-efficient and compact V6 twin-turbo petrol engine with a mechanical flywheel Energy Recovery System (ERS), the revolutionary GT-R LM NISMO is blessed with exceptional straight-line speed, immense all-weather stability and enviable efficiency.

SECRETS OF THE GT-R LM NISMO
To understand its intricacies and appreciate where its advantages lie, who better to explain the thinking behind the GT-R LM NISMO and run through some of its technical highlights than its creator, Nissan’s LM P1 Technical Director, Ben Bowlby:

“Mad. Brave. Genius.” – The NISSAN GT-R LM NISMO CONCEPT

Q1: The GT-R LM NISMO is a pretty wild idea. Where did it come from?

Bowlby: The car is the star at Le Mans, no question. It’s so important because perhaps more than any other, it’s a real engineering race. As a first year entrant we had to ask ourselves how we can stand a chance of being competitive when the main opposition is 15 years and several billion dollars ahead in experience and development. The answer – our answer – was to innovate. We don’t have as big a budget as the other guys, but we are rich in ideas. There’s virtually no chance to beat our rivals at their own game, so innovating gives us a better chance at competitiveness.

Q2: What informed your thinking when designing the GT-R LM NISMO?

Bowlby: To succeed at Le Mans first of all you look at the rule book, and then you look at the race itself. The rules are open to interpretation – as I think we’ve proved – but the race always throws surprises. There are so many potential variables beyond your control – extreme heat, torrential rain, slow traffic, spilled oil and coolant. A big part of the challenge is acknowledging that and designing a car with a wide operating range.

Q3: So what are the GT-R LM NISMO’s key strengths?

Bowlby: It’s hard to separate individual qualities because the concept and design of the car is a system – every element influences the other. If I had to pick out three things I would say efficiency, stability and straight-line speed. But you have to remember these are the product of the aerodynamics, which in turn were only possible to achieve because of the forward positioning of the transmission and engine, and our commitment to run front-wheel drive.

CHASSIS AND AERODYNAMICS

Q4: The GT-R LM NISMO looks very different to its rivals. Why is that?

Bowlby: For years the leading LM P1 contenders have designed cars that follow the same basic design, so the rules have evolved to find ways of limiting their performance by making it difficult to generate very efficient downforce at the rear of the car. It’s also difficult to make maximum downforce, because the dimensions and shape of the rear wing are also restricted. However, the front has always been considered relatively free, so we thought, “Why not turn the rules on their head and make a car with oodles of downforce at the front?” Not only does this give us greater freedom within the rules, but front downforce is generated more efficiently, with less drag. Moreover, with the front end doing most of the work we could trim-out the rear wing and save even more drag, which is invaluable at Le Mans.

Q5: Clever stuff. Tell us more.

Bowlby: Achieving a forward aero balance is quite a trick in itself, but to make it work you need an equally Nisan at Le Mans 2015: Scrutineering Sessionradical shift in mass and tire distribution. It was at this point we took our ideas a stage further and thought, “What if we put the engine ahead of the driver?” It was natural that we chose a powerful, compact twin-turbo V6 like that in the GT-R road car, especially because it meant we also had room to package the ERS system in the front. By mounting the gearbox ahead of the engine and the crash structure ahead of that, we have a chassis that complies with the regulations, has all its major mass over the driven wheels, gives us the all-important forward aerodynamic balance we’d been chasing, and lends itself to a very efficient, low-drag teardrop shape.

Q6: Why is low drag so important at Le Mans?

Bowlby: So much of the Le Mans circuit comprises long, high-speed straights. Low drag gives us a high top speed to eat-up those straights! Having a straight-line speed advantage is also the simplest, safest way to pass other cars. We’ve tried to make a car that gives our drivers that comfort factor of knowing they’ll be able to pass at high speed rather than having to mug slower traffic in the braking areas and corners. It’s a less stressful, less fatiguing, smarter way to race. Low drag also aids fuel efficiency. The amount of fuel consumed in a lap is now mandated, so you may not exceed those limits prescribed by the rules and regulations. Low drag means you’re not on the straights for a long time with wide throttle openings, so not only does a slippery shape mean you’re going faster, but it also means you’re using less fuel and thus increasing your efficiency.

POWERTRAIN

VIDEO: https://youtu.be/UbfNSq7kKDk

Q7: Describe the GT-R LM NISMO’s propulsion system.

Bowlby: In simple terms we have gone with a petrol-electric propulsion system comprising a compact, twin-turbocharged 3.0-litre V6 internal combustion engine (ICE) petrol engine, and a mechanical flywheel kinetic Energy Recovery System (ERS) that runs in the 2MJ class. Turbocharged V6 engines are something of a NISMO specialty, so our philosophy for the ICE was to build a super-efficient version, which has excellent drivability at relatively low rpm. It’s very, very torquey with a very flat power curve, which means we need only run with a 5-speed gearbox. This means we’re changing gear less and putting less wear-and-tear on the transmission components. The engine also has spectacular thermal efficiency, so we extract the most power we can from every last drop of petrol we use.

Q8: What about the Energy Recovery System?

Bowlby: We are running a flywheel-based energy recovery system, as Audi does, but where they use an electrical linkage we have gone with a mechanical system. It’s different and it’s smart and it has huge power potential. In tests on the dyno we’ve comfortably produced 1100bhp from our 8MJ KERS system alone. Combined with the internal combustion engine, we have the potential for a little over 1600bhp at our disposal. Unfortunately, due to the project’s extremely challenging timeframe – less than a year to form the team and design, engineer and develop the car from scratch – we’ve had to be pragmatic and scale things back with the hybrid system for this year’s Le Mans. That’s the flipside of innovation: it hurts when all the pieces don’t quite come together in time. However, we are going to learn a huge amount about getting the maximum from the V6 petrol engine in this year’s race, and you can be sure we’ll be back at Le Mans with full force in 2016.

Nissan GT-R LM NISMO

FRONT-WHEEL DRIVE EXPLAINED

VIDEO: https://youtu.be/Gq8I0_wygpI

Front-wheel drive is very common in road cars, but highly uncommon in pure-bred racing cars. The GT-R LM NISMO is front-wheel drive. It is also front-engined. This is a unique combination for a top-class Le Mans racer.

Q1: Nissan believes this combination is the key to unlocking traction, stability and straight-line speed advantages over the rear-engined, rear-wheel drive cars competing in the LM P1 class. How and why is this the case?

Bowlby: Fundamentally what the GT-R LM NISMO concept gives us is a greater percentage of the car’s mass (around 65%) over the internal combustion engine-driven (front) axle. Combined with the huge amounts of front-end downforce and much wider tyres fitted to the driven wheels we can generate more traction, and run at higher speeds before experiencing aquaplaning in extreme wet conditions. Having the weight, aero and tyre balance on the front also means you have a car that’s inherently very stable, not one that’s sitting on a knife-edge. Providing our drivers with a fast, stable car that’s more forgiving and helpful in those typical Le Mans moments when the unexpected happens was one of our strategic imperatives.

Q2: What challenges does this radical car present the drivers, and how does it feel to drive? Let Michael Krumm, NISMO’s most experienced driver, and the man who has been involved in the GT-R LM NISMO development program from the very first shakedown, put you in the driver’s seat.

Krumm: The driving position is very far back behind the engine, so it feels unusual the first time you sit in there (as you can see much more of the front end of the car than you usually would). But then you drive it and, initially to your surprise, you find it’s very sharp on turn-in and the traction is extremely good. We’re putting a lot of horsepower through the front wheels, so I expected it to have loads of wheelspin, but it pulls really well.

The wheels always “pull” the car, which means as long as you are under acceleration, the rear end of the car will always be stable and cannot suddenly spin you around. That is particularly helpful in wet conditions. Also, there are certain types of corners where this “pulling” of the car can actually create more grip than a conventional rear wheel driven car.

I think it’s going to be very interesting at Le Mans because we’re going to be quicker and slower than other cars in different places on the track. It’s going to be really exciting to see where we are better. If it’s wet or a little dangerous, suddenly I think the front-wheel drive is going to show some really serious advantages.

The aerodynamic concept and low-drag of the car means when you get onto the straights it just goes and goes and goes. We’re going to reach really good top speeds at Le Mans. Usually when you drive an LM prototype you accelerate quickly, but then you hit a bit of an aerodynamic brick wall; the GT-R feels really slippery through the air. I love the V6 engine, too. It’s a really nice turbo engine that has terrific torque right through the rev range.

TESTING THE NISSAN GT-R LM NISMO

VIDEO: https://youtu.be/FFvyKgokSYs

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