INSIGHT: Audi's new R18 embodies 2014 P1 rules changes

INSIGHT: Audi's new R18 embodies 2014 P1 rules changes

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INSIGHT: Audi's new R18 embodies 2014 P1 rules changes

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Contrasting the 2013-spec R18 (silver) with the new iteration (black) illustrates the direction P1 cars are heading (Audi Sport photos)

Audi’s newest P1 challenger represents the German manufacturer’s most technologically ambitious prototype to date, although the advances contained within the new chassis and bodywork have little to do with the familiar tools of the trade.

Unbolted from the car, some of the biggest internal items on the 2014 R18 would be hard to distinguish from the equipment found on its predecessor.

Of the known componentry, the new R18 uses a derivation of its Le Mans-winning 3.7-liter V6 that feeds the rear wheels. Revised, more powerful versions of the electric Motor Generator Units (MGUs) drive the front wheels, and the suspension is mostly a carryover from 2013. Almost everything else has come from a clean sheet of paper.

Click here for an in-studio video of the new Audi.

Externally, the most obvious difference is a new carbon fiber monocoque that features a longer, narrower tub ahead of the windscreen and a taller cabin. Sightlines on the new R18 are greatly improved, with the a-pillars no longer serving as a hindrance to apex viewing. The latest P1 rules call for drivers to sit higher in the cockpit and at a different angle, leading to initial driver complaints about being too far removed from the floor and the dash being too high.

New R18 spied testing at Sebring (Perrywinkle Jones photo)

Compared to the shorter, stubbier 2013 R18, the 2014 car moves its weight rearward within its wheelbase. The most obvious difference can be found with the relative placement of the front of the windscreen, which now sits at the trailing edge of the front wheels. The R18’s aerodynamics has completely changed for 2014, starting at the front of the car where a wider gap has been created to allow air to flow between bottom of the nose and the top of the underwing profile. Enough free space has now been created in the “tea tray” area to allow Audi to consider the use of an actual wing element, rather than the traditional combination of the nose’s underwing profile and strakes.

On the topside, the tapered nose and tub aligns nicely with the cabin and slender engine cover, giving the new R18 less frontal area which preserves some of the power that was needed to push the 2013 car’s blunt nose through the air.

A rule change has forced Audi to move its exhaust outlets from the rear wheel wells a philosophy similar to the blown diffusers recently seen in Formula 1 to exits the Audi Sport engineers have fared neatly into the engine cover. The shape of the new R18 is best described as an evolution of the previous model, but every surface on the car is brand-new, including the floor and diffuser which, per the rules, makes less downforce.

The 2014 P1 rules call for narrower tires closer to what’s been used on P2 cars in recent years, larger wheel arch vents and, following a trend that appeared in open-wheel racing in 1999, wheel tethers have become mandatory.

A new, smaller carbon fiber gearbox housing has been created to pare weight from the rear of the R18, and a new, lower profile flywheel and Energy Recovery System housing sits in the passenger seat. The R18 uses MGUs to generate and release power stored in the ERS unit, and in an interesting development, new software algorithms have been written to allow the MGUs, which drive the front wheels independently, to behave like a limited-slip differential.

The previous R18 had a version of this tuning option for its drivers to tailor the balance of the car, but major strides have been made for 2014, giving drivers everything from complete lockup across the front axle to lesser gradients that can tune reasonable amounts of understeer or oversteer out of the chassis while on the fly.

Unlike most open-wheel cars, the lack of cockpit adjustable anti-roll bars was once a limitation for prototype drivers, but with the R18’s MGUs working the front tires based on preference, pilots have a significant amount of control to optimize the car during a stint.

The new levels of chassis tuning through the MGUs has also led Audi to alter its approach to base setups for the prototypes. Handling imbalances that once required a trip to the setup pad can now, in most cases, be managed through the MGUs, allowing more track time during practice. Provided the setup is close for the race, drivers can use their fingertips to dial in their preferred handling characteristics, reducing the degree of compromise required by each pilot.

One can only imagine what the likes of Harry Miller and George Bignotti would have thought about advancements such as these back in the day.

Audi has incorporated a new, shaft-driven electronic turbocharger into the R18’s powertrain that works off the variable-vane mechanical turbo. An additional, albeit lesser amount of energy is produced by the e-turbo and sent to the ERS flywheel for storage and use.The ACO’s mad push toward energy recovery and efficiency has led to Audi and other turbo-friendly P1 manufacturers to adopt e-turbos in an effort to reduce fuel consumption at lower revs when turbo spooling is required. With the ERS-fed e-turbo aiding boost production, lag is reduced and the need for a heavy stab at the throttle to build revs through burning fuel (to create exhaust flow to wind up the turbo) is lessened.

As much as the e-turbo sounds like a tool for producing extra power, it’s being used in this application to save fuel by making life easier on the combustion engine during initial acceleration.

Based on its ERS output, Audi expects to work with a 30 percent reduction in fuel allowance, which has driven the costly pursuit of ultimate fuel efficiency. The 2013 R18 made something in the 540hp range, and with the MGUs activated and at full song above 75mph (per the rules), nearly 800hp was on tap.

A change to ERS policies for 2014 has eliminated the minimum speed threshold, permitting hybrid power to be unleashed at any time. Greater energy storage up to 8MJ for manufacturers that opt for the maximum will also deliver longer bursts of electric energy.

The ACO’s fundamental shift in philosophy towards manufacturer P1 cars means the age-old quest for more power and torque has become a secondary concern. Working with the available fuel allotment to reach the end of the race without running dry, which ruined many great Group C and Formula 1 duels in the 1980s, is once again a pressing concern, leading engine builders to go against their nature with their respective 2014 powerplants.

If that sounds a lot like P1 racing will change into contests where unadulterated speed is no longer the top priority, you’re seeing things in the same way many P1 drivers, engineers and designers view what lies ahead.

With ERS units now fully incorporated into P1 cars more than the limited, tack-on power adders employed through 2013, the R18 has new software strategies that dictate how aggressively the flywheel unit captures and releases its electricity. Waiting to generate electricity through the MGUs under braking, which had been the norm, is only part of the equation. The methods behind charging ERS units will evolve throughout the year, but in general, hybrid-equipped P1 cars will look for more opportunities to use electricity to move forward.

Like everything else about the 2014 P1 regulations, items like ERS that were once regarded as nothing more than performance boosters have become part of the fuel-saving equation.

Another aspect of the 2014 P1 rules that could be a challenge for fans to accept is the shift in what teams are looking for from their drivers. The attacking style of an Allan McNish or Romain Dumas was perfectly suited to P1 racing though 2013, but with fuel allotment governing outright lap times in 2014, speed is no longer the most prized asset a P1 driver has to offer.

The ability to set the fastest laps while meeting a target fuel consumption figure is the new, almighty skill that will be demanded of factory P1 pilots. It’s a bit like asking Usain Bolt to run with shoes that are three sizes too small. He’ll still be fast, but nothing like the record-breaking speed that packed stadiums.  

Thanks to the 2014 P1 rules, factories are on the lookout for those who can maintain a predetermined pace while saving the most fuel. One of Porsche’s new P1 drivers was signed for this very reason, and while this formula is in place, some of the P1 veterans will need to adapt or risk losing their factory rides.

To give an example, this new demand requires drivers to question whether making a dive-bomb pass into a hairpin is the right choice, or if waiting, carrying more speed through the corner, accelerating more smoothly on corner exit and attempting the pass at a later time is better for fuel saving. Completing the pass into the hairpin would gain a position, but it would come with a reduced rolling speed, which would require more fuel to be spent as the engine spins up from a lower rpm.

Most racers wouldn’t flinch they’d rocket into the braking zone, make the pass and mash the throttle out of the corner. Those instincts, under the 2014 P1 rules, could lead to a one-way ticket to the unemployment line.

As silly as that scenario might sound, it’s one of the items Audi has simulated, along with developing lifting strategies places on the circuit each lap where its drivers are meant to lift off the throttle for specific durations to save fuel. Lifting to save fuel is nothing new, but going into a race with an articulated plan on key places to avoid accelerating doesn’t sound like much fun. When a set of rules creates a scenario where using the throttle is considered a detriment to success, the essence of motor racing has been lost.

Audi, like the other factory P1 teams, has expanded its technical department with efficiency engineers, a new breed of techno boffin. Audi’s team of efficiency engineers will grow next year as another layer of staff will be added to concentrate solely on the hybrid system, but department’s domain also covers the efficient use of fuel, tires, downforce, drag and any other category that influences the car’s ability to make it to the finish line within its fuel limitations.

With the 2014 rules in mind, one could argue this group of engineers most of whom spend each race staring at computer screens while secluded from the track have become more important than many of the race engineers on pit lane.

Big increases in ERS output, reduced weight, reduced rolling resistance through narrower tires and appreciable gains in aerodynamic efficiency have led to a potential decrease in qualifying times at Le Mans. Simulations predict a drop in the two-second range, which is encouraging.
 
Outside the confines of the race, new hybrid P1 cars like the Audi R18 are capable of producing ferocious speeds, but for those who prefer to watch prototypes in an all-out sprint instead of an energy-conserving jog, next year’s races could struggle to generate the excitement we’ve grown to love.

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