The Lamborghini Huracan Super Trofeo and GT3 are the only race cars in the world built on exactly the same production line as their Coupe and Spyder road car sisters.
Both are based on Lamborghini's "entry-level" road car, the rear-wheel-drive Huracan LP580-2, whose 5.2L, 90-degree V-10 produces 580 hp at 8,000 rpm, 398 lb-ft of torque at 6,500 rpm. Tipping the scales at 3,062 pounds, this mid-engine road car features an ideal 48/52 percent front-to-rear weight distribution out of the box, and so has the right stuff on which to base a world-class race car.
"We homologated the Huracan GT3 with a lower output than the road car to cover the possibility of ballast and a smaller air restrictor on the engine being applied should we fall outside the FIA's Balance of Performance index," explained Maurizio Reggiani, Lamborghini's R&D director. "This gives us the possibility to increase engine output as the season progresses if the opposition proves faster."
Thus, at this point the Huracan GT3 motor produces around 530 hp with a 38mm diameter air restrictor in place, which is around 10 percent down on the road car's output. To improve durability, the engine has strengthened crankshaft bearings and is mounted to the chassis with solid mounts. The secondary fuel injectors that reduce low-speed emissions of the road car are not required, so the race motor has 10 fuel injectors dispensing 98-octane juice from the 120L (32-gallon) FT3 racing fuel tank. The ECU is a Bosch MS6.4, which also looks after the traction control, shifting control, TFT display control, and data-logging, while the custom-built electrics are taken care of by a fully configurable Cosworth Powerbox.
"The engine is both strengthened internally and under-stressed in power output compared to the road version, so it should be able to go 10,000 km between rebuilds if it is not abused," Maurizio said. When it gives its all under race conditions, fuel consumption is in the order of 1.5 km/L! That's roughly 3.5 mpg if you're wondering.
As you would expect, the torsional stiffness of the race car is far greater than that of the road car. The Huracan GT3 uses a hybrid construction with aluminum reinforced by carbon-fiber in the areas of greatest torsional stress. Like the road-going Huracan models, the GT3 has a carbon-fiber firewall.
The stout FIA-approved rollcage that extends to the rear contributes significantly to the car's torsional rigidity number of 33,190 lb-ft/degrees of deflection. This core is then wrapped in composite body panels made from a combination of CFK, Kevlar, and glass-fiber.
Safety is a very important issue, and as well as the integrated rollcage and six-point harnesses, the Huracan GT3 also protects its driver with the latest 8862 Spec race seat that will resist an astonishing 75 g's of acceleration, or three times the rating of the previous seat. A seven-nozzle fire extinguisher system looks after any unintended combustion.
I was amused to see wooden blocks making up the front trailing edges of both the front and rear wheel arches. Maurizio explained that these are sacrificial sections for when you hit high curbs on some tracks. "They serve the same aerodynamic purpose, but compared to carbon-fiber cost next to nothing to replace."
While all its competitors use quick-release Dzus fasteners for some body panels, the Huracan GT3 is unique in applying this fixing method to all its body panels. As races can be won or lost in the pit lane, this makes a crucial difference when a quick replacement is required under race conditions.
The involvement of Italian motorsport genius Gian Paola Dallara in such a project is not unexpected, and Dallara Engineering worked closely with Lamborghini's race engineers to hone the aerodynamics, which give the GT3 a low-drag, high-downforce advantage. Dallara was also responsible for the fully adjustable suspension, which uses Eibach springs and Öhlins dampers to support the modified double wishbones and uprights at each corner. The antiroll bars are adjustable and the suspension pickup points have been altered to optimize the tire contact patches. The rules allow these to be moved within a 50mm box, which provides a lot of leeway to set negative camber in the 3- to 4-degree range.
The ride height is set for reflex camber, the extra 15mm of ground clearance at the rear working with the downforce of the big rear wing for optimum balance at speed. This is a major difference between the 369,999 euro Huracan GT3 and the 240,000 euro Super Trofeo version, which has a bit more engine power but less mechanical grip and aerodynamic downforce.
The GT3 achieves its quicker lap times through its superior handling and grip and is more than a second faster on a lap of Valencia. On a circuit with longer straights like Monza, the two cars are much closer in lap times, whereas at Silverstone the GT3 gains under braking and acceleration through the turns.
Brembo supplies the 380mm and 355mm vented steel racing brake discs, clamped by big six and four-pot calipers front and rear, respectively, fitted with endurance race pads. Under the car, big tubes direct extra cooling air to the brakes. The series eschews carbon ceramic brakes for cost reasons.
The Bosch motorsport ABS system offers a choice of 10 positions that the driver can select via a knob on the steering wheel. The same is true for the 10-position traction control that can be tweaked according to available surface grip and the degree of tire wear.
In terms of curb weight, despite being shorn of air conditioning and all the creature comforts demanded by Lamborghini's road car customers, the GT3 still tips the scales at 2,712 pounds dry and 2,822 pounds ready to race with 66 pounds of ballast. "Once again, we started heavier than the minimum weight we are allowed of 2,646 pounds as this gives us room to maneuver," he said.
In a world where more and more supercars are gravitating toward turbocharging to meet ever-tightening emissions laws, the Lamborghini V-10 stands out as a paragon amongst naturally aspirated high-performance engines. Attached to a flywheel weighing 5.5 pounds, about half that of the Huracan road car version, the V-10's willingness to rev fast and high is noticeably enhanced, while the throttle travel is really easy to meter precisely.
While the gearbox of the Huracan Super Trofeo race car is mounted transversely as on the road car, the physical space required for the big underbody rear diffuser on the GT3 car required a technical solution in the form of an inline six-speed sequential gearbox made by Hör Technologie in Germany. Inputs from the paddle shifters reach the gearbox via a Megaline pneumatic actuator.
I know the Valencia Circuit pretty well and was looking forward to really leaning on the mechanical grip that the slick tires and aerodynamic downforce endow on the Huracan GT3. However, it was not to be. Rain is not a regular visitor to southern Spain, but unfortunately, this was the Sunday when much of the country was blighted by heavy downpours and flooding. Precipitation began early in the morning, and my first test session at lunchtime was more of an exploratory run to establish grip levels and the wet line whilst dodging puddles.
After our test car was pulled back into the pits, the grid for World Final of the 2016 Lamborghini Blancpain Super Trofeo assembled. The rain became progressively heavier through the event, turning it into something akin to a boat race. The irony of the multiple Lamborghini V-10 soundtracks emerging from the spray rather than the V-12s favored by offshore powerboat racers was not lost on us!
In the streaming wet conditions, visibility and grip were at a premium, and as we watched the race from the big monitors in the VIP area, we could see some big slides and the odd excursion into the kitty litter. With the pace car and yellow flag working overtime, the race was effectively over almost 8 minutes before the checkered flag fell.
Luckily for us, by the time Dennis Lind (No. 60, Raton Racing) was proclaimed Pro Class World Champion in the World Final of the 2016 Lamborghini Blancpain Super Trofeo, the rain had abated and it was time for our second test session.
A good analogy for the technology gap between the cockpit controls of the Huracan GT3 and the Group C Porsche 962 I tested in the late '80s would be the difference between a current F-16 fighter jet and a Vietnam-era A4 Skyhawk.
Electronics are a fact of life in today's road and race cars, and the Huracan GT3's controls require some explanation. Once you are in the fixed driver's seat with the detachable steering wheel in place, you find the perfect driving position by adjusting the pedal box fore or aft.
"Lighting up" the car requires sliding aside the transparent safety cover for the red "Main" switch, giving it a push to wake up the electronics, and then pushing the green "Ignition" button next to it. To actually start the car, you then need to step on the brake pedal and pull one of the clutch levers below the paddle shifters and press the start/stop button on the steering wheel. Then you can pull the right paddle to engage first gear.
I have always been fascinated by the pit lane limiter device, regularly seen and heard in action in FIA GT and F1 races. At its core is a piece of software that limits the engine spark to prevent the car going over a set speed in each gear. On the Huracan GT3, that speed is 50 km/h in first gear and 80 km/h in second.
The system is activated by pushing a button on the top right of the aircraft-yoke-style steering wheel, and sequential blue LEDs illuminate from left to right across the top of the instrument panel as you go faster. With the pit lane limiter off, the LEDs turn yellow, orange, and red to show engine revs and are easily seen in your peripheral vision.
You can hear the limiter restricting the engine spark like a misfire, and no matter how hard you press the throttle, the car will not go over an indicated 49 km/h in first. So many drive-through penalties have been caused by drivers forgetting to engage this simple device.
The paddle shift gear change is not only lightening fast but also totally seamless. As I have always held, the smooth engagement of racing gearboxes gives the lie to silly marketing led road car paddle operated systems that deliver a "race car feel" kick in the back when you are in Sport mode. The last thing you need is a coarse interruption of power to destabilize the car when cornering on the limit, especially in the wet.
Luckily, Valencia has good drainage, so with a uniformly wet surface for the treaded Pirelli rain tires to bite through, the only real hazard was the patch of gravel on Turn 10, just off the race line, where a car had been dragged out of the gravel trap.
Modern competition rain tires are an engineering marvel, and with the variable traction control turned up to about 75 percent, I quickly found that I could deploy all the cavallini once the steering wheel was straight, and a fair amount of them exiting the more open bends.
In fact, I could get enough exit speed from Turn 13 to reach almost 140 mph in fifth gear before braking on the 2,874-foot-long main straight. In the dry, a faster exit speed from the preceding corner and a later braking point would easily have seen a 155mph terminal speed before braking.
I had been watching the lap times of the leading cars in the dry the day before and during today's very wet race. The difference between wet and dry lap times on the 2.5-mile track was about 13 seconds, with the fastest dry lap posted on Saturday in the Pro Class being 1:31.424 seconds.
Valencia has a couple of low-speed bends that go on longer than you think when you enter them, and even in the dry you have to be conservative with the throttle if you are not to provoke understeer or indeed oversteer depending on how the car is set up.
Taking modest entry speeds here in the wet, I was thankful for the extremely easy-to-meter throttle and progressive power delivery of the naturally aspirated V-10. It occurred to me on one of these wet laps that a turbocharged car, especially one with sudden delivery characteristics, would have been a nightmare in these conditions. It is this delicate throttle control, superb steering, and well-dialed-in chassis that make the Huracan GT3 feel all of a piece, intuitive to drive, and not a car that will turn around and bite you.
Up until you are in a position late in a race where your tires are going off and you have to really manage the front and rear ends, this car handles in a very seat-of-the-pants way that inspires a lot of driver confidence. This is a crucial characteristic that helps the driver, both in a long race and when dicing wheel to wheel.
The Huracan GT3 derives a lot of its performance balance and competitiveness against other makes from its superb handling and excellent aerodynamics. That is certainly how it feels on track, and my over-riding impression of the car is that once you have mastered all the electronic gadgets that are part and parcel of a sophisticated modern racing car, it is user friendly and easy to drive.
Even though I did not have the opportunity to really lean on it in the dry, the transparency of its controls, the exquisite feedback through the seat of your pants, and the ease with which it can be recovered from a slide go a long way to framing its good balance and progressive handling.
While watching the Lamborghini Super Trofeo racing is exciting in itself, it is only when you see the Huracan GT3 snatching podium places in international GT races against some very distinguished opponents that you realize just how good this car really is.
Lamborghini's Squadra Corsa racing division has existed since 2008. In 2014, it was decided to field the all-new Huracan in a one-make series under the name Lamborghini Super Trofeo, first in Europe and then in the USA and Asia.
Taking their new car a step further to contest the GT3 class in international championships took a little longer. The Huracan GT3 made its show debut in January 2015, and to say the response from potential customers was overwhelming would be putting it mildly.
Lamborghini found itself flooded with orders for 40 cars, a lot more than it had originally expected. Of these 40 cars, 20 went to customer teams, 13 were entered in various GT Championships, with a total of 78 race weekends being contested.
From day one, Lamborghini had promised full support for all customer teams all over the world, with a particularly large number of teams in Australia. Thus, one of the most amazing things that transpired was Lamborghini's ability to fulfill this promise of both on-site technical support and spare parts backup despite the sudden and unexpected growth in the number of race cars out there and the logistics nightmare it posed.
As a result of the professionalism of the teams, which were well supported by Squadra Corsa, in the 2016 season Lamborghini Huracan GT3 race cars took the championship titles in the GT Asia Series and the GT Open, came second in the British GT, and third in IMSA and the Italian GT.
Within these various race series, the Huracan GT3 scored 18 overall victories, 17 seconds, 18 thirds, and 22 pole positions, which speaks volumes for its speed and reliability.