The R8 made its parents extremely happy when it was an infant, as his first words were: “ASF”, “quattro” and “FSI”. We’ll start with the first, which stands for Audi Space Frame and describes the company’s aluminum vehicle fabrication technology.
Body and Chassis
The Audi R8’s body is initially built in three separate sections, the front end, the central compartment and the rear end. These make up the substructure of the car, while the pillars, the roof, side walls, cover panels and doors are added after the first three are joined - The elements of the ASF skeleton are bonded using manual weld seams, while the body panels are fixed using self-piercing rivets and automatically-applied self-tapping screws.
The vehicle’s body in white uses three types of aluminum: 75 percent of this is represented by extruded aluminum sections, vacuum-cast nodes account for 8 percent, while the remaining 17 percent goes to the aluminum panels of the car. The last use alloys that cure under heat, so the R8’s body achieves its final hardness at the end of the painting process, when the vehicle is drying in the oven. The R8 also uses other lightweight materials, such as magnesium, which is found in the frame that supports the engine.
The Spyder shares about 70 percent of its parts with the coupe. The engineers reinforced the bulkhead and the transmission tunnel in order to compensate for the loss of rigidity brought by the use of a canvas roof. Other measures used with the same aim include the strengthening of the side sills, as well as of the pillars.
The Coupe comes with plastic plates under its floor to create a flat underbody, but on the Spyder these are built from aluminum and doubled by a crossbeam in order to increase rigidity.
Even with all the aforementioned reinforcements, the body in white of the Spyder tips the scales at just 6 kg (13.23 lbs) higher compared to that of the coupe. The impressively small difference doesn’t only come from the lack of the roof, but also thanks to the extensive use of carbon fiber. The material is used for the large top cover, as well as for the doors of the vehicle.
The Audi R8 also turns to special plastic as part of its diet - the engine compartment cover and the rear spoiler are made from fiber-reinforced plastic, while thermoplastics are found in the aprons.
Of course, the R8 Spyder can’t escape the weight and rigidity penalty in the end. Compared to the coupe, it loses 20 percent in stiffness and gains 100 kg (220.5 lbs). Nevertheless, the balance of the car has been kept intact. The axle load has moved just 1 percent towards the rear compared to the coupe, with the Spyder showing a ratio of 43:57.
It’s time to move on to the engine bay now. Our Audi R8 test car had a 5,204 cc (317.6 cu.in.) V10 naturally-aspirated powerplant and so did the Lamborghini Gallardo
we drove in the past. Yes, the two share the engine, but each offers a distinct output and sound.
The standard R8 V10 delivers 525 hp at 8,000 rpm and 530 Nm (391 lb-ft) of torque at 6,500 rpm, while a Gallardo LP 560-4 offers 560 hp at 8,000 rpm and a peak torque of 540 Nm (398 lb-ft). The two sets of output values come derive from the fact that there are a few mechanical differences between the two units. Each comes with its dedicated intake and exhaust systems and, of course, with specific ECU mapping.
We have to explain that the V10 powerplant was first seen on the Lamborghini Gallardo, in the previous 5.0-liter incarnation, but this was based on the Audi 4.2-liter V8, which had been developed by Cosworth.
Even in the more civilized form found on our test car, the V10 engine still delivers 100.9 hp per liter, a value that’s doubled by others which are just as enjoyable, such as the 8,700 rpm maximum rev limit.
The 90-degree configuration of the ten-cylinder unit reduces its height and thus lower the car’s center of gravity.
When the engine undergone the aforementioned transformation from 5.0 to 5.2-liters, it received multiple changes, such as being gifted with dry sump lubrication. This further reduces the height of the engine, as there’s no need for a large oil pan under the powerplant.
There lubrication system uses an external tank and oil pump, which takes the oil separately from the crankshaft, chain box and the cylinder heads, using a pair of coolers to lower the temperature. On the skidpad, the R8 V10 can deliver a lateral acceleration of about 1.2 g, but the system is able to maintain perfect lubrication up to a value of 2 g.
The unit also received FSI, Audi’s version of direct fuel injection. Fuel is injected in the combustion chamber at a pressure of up to 120 bar. The injectors are placed on the side of the cylinder head - the fuel mixture acts like a vortex, cooling the cylinder walls and thus reducing knocking sensitivity. This enables the engine to use a high compression ratio of 12.5:1, increasing both performance and efficiency.
One of the ways in which the engine manages to produce its divine soundtracks comes from its ignition intervals. Each pair of opposing connecting rods use a common crankpin, as the crankshaft features a common pin shaft configuration. Among others, this means that the unit alternately fires in 54 and 90 degree intervals, which dramatically impacts the way it sounds.
The engine’s flexibility is offered by the variable valve timing, as well as by the architecture of the intake manifold. This uses ECU-controlled tumble flaps to vary the airflow. For example, at low revs and load, the air is swirled, which results in a more even mixture in the cylinders and therefore superior combustion efficiency.
The Audi R8 also shares its optional robotized single-clutch manual six-speed transmission with the revamped Lamborghini Gallardo, while the only difference between the two implementations is the software. The designation of the gearbox is, of course, also distinct: Audi calls its version R-Tronic, while for the Italian model they named it e-gear.
The paddles on the steering wheel send an electric impulse to the transmission’s hydraulic system, which works at a pressure between 40 and 50 bars. The hydraulics activate the clutch and also take care of the changes themselves. At full blast, the system can deliver blistering 100 ms shifts.
Since the Audi R8 uses a mid-engined layout, the quattro permanent All-Wheel Drive system needed a dedicated layout. It all starts with the aforementioned gearbox, which is placed transversely behind the V10 powerplant.
There’s a shaft that goes through the engine to the center differential, a viscous coupling unit with electronic control. The standard setup is nothing like Audi’s usual 4WD one, sending 85 percent of the power to the rear. Here, we find a mechanical LSD that can lock up to 25 percent under power, with the value increasing to 40 percent during overrun. Should the front axle need more power, the system can offer it up to 30 percent.
The R8 is suspended on double forged aluminum wishbones at all corners, a motorsport-proven solution. Audi tops this with its magnetic ride adaptive suspension. This constantly monitors the road profile and driving style and adjusts the damping characteristics for each wheel.
For example, when the vehicle enters a bend, the damper of the outermost wheel is hardened, in an effort to reduce body roll. The system also allows the driver to choose between two settings, normal and sport.
Inside the shock absorbers, we find synthetic hydrocarbon oil that features microscopic magnetic particles. The particles can react to electrical current being applied to a coil - they can form a 90 degree angle to the direction in which the oil flows through the channels in the piston and thus stop the flow. The process offers significantly faster response times compared to hydraulic-only adaptive suspension system - a few milliseconds are enough for the particles to rearrange.
The V10 models use a specific 10-spoke Y-shaped design for their forged alloy wheels, with the standard setup including a tire size of 235/35 up front and 295/30 at the back.
The standard deceleration hardware on V10 models is comprised of vented and perforated steel brakes, such as the ones on our test car. The front wheels use 365 mm (14.37-inch) rotors with eight-piston calipers, while at the back we have 356 mm (14.02-inch) discs with six-piston grabbers.
As an optional feature, you can choose carbon ceramic brakes featuring 380 mm (14.96-inch) rotors that work with six-piston calipers up front, as well as 360 mm (14.17-inch) rotors and four-piston grabbers at the rear.
The steel discs feature a wave profile for the outer area, saving 2 kg (4.4 lbs) compared to a traditional design. As for the carbon ceramics, these offer a 12 kg 924.6 lbs) weight reduction versus the aforementioned steel brakes.Continue reading
AUDI R8 V10 Spyder technical data summary
Engine: 5204 cm3 cc V10 petrol
Transmission: R-Tronic single clutch automated manual
Dimensions: 174.5 in OR 4432 mm length / 75 in OR 1905 mm width / 49 in OR 1245 mm height
Get full technical data for AUDI R8 V10 Spyder →