Both are based on the rear-wheel-drive Huracán LP580-2, whose 5,208cc 90-degree V10 produces 580hp at 8,000rpm, 540Nm of torque at 6,500rpm. Tipping the scales at 1,389kg this mid-engine road car features an ideal 48/52% front-to-rear weight distribution out of the box, and so has the right stuff on which to base a world-class racecar.
“We homologated the Huracán 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 Huracán GT3 motor produces around 530hp with a 38mm diameter air restrictor in place, which is around 10% down on the road cars 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 120-litre 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 bespoke 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 10,000km between rebuilds if it is not abused,” said Maurizio. Giving its all under race conditions, fuel consumption is in the order of 1.5 km/L!
As you would expect the torsional stiffness of the racecar is far greater than that of the road car. The Huracán GT3 uses a hybrid construction with aluminium reinforced by carbon-fibre in the areas of greatest torsional stress. Like the road going Huracán models, the GT3 has a carbon-fibre firewall.
The GT3 achieves its faster lap times through its superior handling and grip and is over a second quicker at Valencia. On a circuit with longer straights like Monza, the two cars have similar lap times, whereas at Silverstone the GT3 gains under braking and acceleration through the turns.
The stout FIA-approved roll cage that extends to the rear contributes significantly to the cars torsional rigidity number of 45,000Nm/degree. This core is then wrapped in composite body panels made from a combination of CFK, Kevlar and glass-fibre.
Safety is a very important issue, and as the well as the integrated roll cage and six-point harnesses the Huracán GT3 also protects its driver with the latest 8862 Spec race seat that will resist an astonishing 75g deceleration, 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 kerbs on some tracks. “They serve the same aerodynamic purpose, but compared to carbon-fibre cost next to nothing to replace,” he said.
While all its competitors use quick release Dzus fasteners for some body panels, the Huracán 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 down force advantage.
Dallara was also responsible for the fully adjustable suspension, which uses Eibach springs and Öhlins dampers to support the bespoke double wishbones and uprights at each corner. The anti-roll bars are adjustable and the suspension pickup points have been altered to optimise the tyre 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 three to four degree range.
The ride height is set for reflex camber, the extra 15mm of ground clearance at the rear working with the down force of the big rear wing for optimum balance at speed. This is a major difference between the 369,999 euro Huracán GT3 and the 240,000 euro Super Trofeo version, which has a bit more engine power but less mechanical grip and aerodynamic downforce.
Brembo supply the 380mm and 355mm vented steel racing brake discs, clamped by big six and four-pot callipers 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 ten positions that the driver can select via a knob on the steering wheel. The same is true for the ten-position traction control that can be tweaked according to available surface grip and the degree of tyre wear.
In terms of kerb 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 1,230kg dry and 1,280kg ready to race with 30kg of ballast. “Once again we started heavier than the minimum weight we are allowed of 1,200kg as this gives us room to manoeuvre,” he said.
In a world where more and more supercars are gravitating towards turbocharging to meet ever tightening emissions laws, the Lamborghini V10 stands out as a paragon amongst naturally-aspirated high performance engines.
Attached to a flywheel weighing 2.5kg, about half that of the Huracán road car version, the V10’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 Huracán Super Trofeo racecar 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 tyres and aerodynamic downforce endow on the Huracán GT3. However, it was not to be.