Could supercharged-and-turbocharged five-cylinder versions of the Lamborghini Huracán and Audi R8 be on the way? That appears to be a distinct possibility, based on comments made recently by Audi technical boss Ulrich Hackenberg, as well as the appearance of an Audi TT Clubsport Turbo concept with just such an engine at the VW Group festival at Wörthersee.
Both the Huracán and the R8 are powered by 5.2-liter naturally aspirated V-10 engines and neither of them offers an alternative, with Audi Quattro GmbH boss Heinz Peter Hollerweger confirming at an R8 pre-launch event that there would not be a V-8 version of the second-generation supercar.
Lamborghini president Stephan Winkelmann has acknowledged, however, that Asian tax laws have made life difficult for big-engined supercars. And Hackenberg hinted that both the Lamborghini Huracán and the Audi R8 would have to adopt a smaller, boosted engine to fulfill their sales potential, especially in China.
Yet until just recently, there was no obvious powerplant in the Volkswagen Group that could fit the bill with enough strength and character to power a Lamborghini or an R8.
That changed when Audi showed the TT Clubsport Turbo concept car. That car’s turbocharged and supercharged 2.5-liter five-cylinder engine makes an incredible 600 horsepower and 479 lb-ft of torque. The TT Clubsport Turbo’s engine uses an electrically driven supercharger to boost bottom-end response, eliminating turbo lag and inertia. A similar system will be introduced on the Audi SQ7’s diesel engine within a year and was employed in the RS5 TDI concept we reviewed last July. (You can read more about the concept of electric supercharging in our deep-dive look.)
The twin-boosted five’s output might have to be detuned in production if it finds its way into the Huracán and R8, but not for engine-longevity reasons. The issue is that the five-cylinder (at least in concept form) puts out 60 more horsepower than does the R8’s naturally aspirated 5.2-liter V-10.
At 2.5 liters, it would cut cleanly through the tax laws enacted by the Chinese in March 2013, which include an annual consumption tax on cars that rises with engine capacities. They begin to bite at 2.0 liters but draw the most blood above 4.0 liters. Above 2.0 liters, the tax jumps to nine percent and continues on a linear scale to 40 percent for engines of 4.0 liters and above. That would make it pointless for the Huracán and the R8 to adopt the twin-turbo 4.0-liter V-8 from the RS7 and other VW Group vehicles, as such models would draw roughly the same consumption tax as the existing V-10s.
“Electric boosting would be necessary for any smaller motor, even if it’s turbocharged,” Quattro GmbH’s Hollerweger said. That would dictate 48-volt electrical systems and a lithium-ion battery pack to generate enough energy to help the internal-combustion engine. But using electrification to give a leg up to smaller internal-combustion engines comes at a price—both in cost and in weight, which is the traditional enemy of supercars. “The problem with electric boosting is that this type of battery is much heavier and the weight disadvantage of the battery has to be countered by the performance gain,” Hollerweger admitted.
But there’s another issue for any smaller-engine Huracán or R8. At this month’s RS3 launch, Quattro GmbH engineering boss Stephan Reil categorically stated there was no approved development project to slip a lesser motor in Audi’s flagship sports car. By: caranddriver