For the reason that launch of Unbound Vol. 6: Head to Head, we’ve been riding the Audi hype train to have fun the automaker’s return inside Need for Speed’s digital world.
We have now uncovered the in-game updates and even looked back on our top five tuned Audis featured on Speedhunters through the years. But for this week’s theme, we’re taking you all back to highschool… quattro school.
You’ll discover a quattro variant of virtually every production Audi in 2024. Yet its origins date back to the Seventies, with engineers Jörg Bensinger and Walter Treser widely credited for pioneering (and being the driving force behind) the technology ahead of its global debut within the 1980 Ur-quattro road automobile.
Then, as Audi rolled it out inside their rallying campaign from 1981 onwards, it quickly became apparent this all-wheel drive revolution was here to remain. Not only did Audi claim two World Rally Championship titles and 24 victories between ’81 and ’86, but there hasn’t been a two-wheel drive winner of the WRC since Lancia’s 037 in 1983.
Audi’s quattro is likely to be probably the most renowned all-wheel drive system on the planet, but it surely wasn’t the primary of its kind – not by an extended shot. Early four-wheel drive transmissions date back to the inception of the interior combustion engine. Dutch brother Jacobus and Hendrik-Jan Spijker paved the way in which in 1902 with their Spyker 60 H.P.
In the next a long time,, several 4×4 systems were developed for military and off-road use, including the Willy’s Jeep and Series 1 Land Rover.
What about ‘normal’ cars? Well, Jensen’s FF from 1966 and Subaru’s Leone in 1971 each utilised all-wheel drive long before Audi joined the party. What made quattro different was how it powered all 4 wheels.
Quite than use a heavy, inefficient transfer box to drive each axles, Audi developed a lighter, smaller centre differential to deliver the ability front and rear. Then, when traction became much more limited, the centre diff may very well be locked with a vacuum-operated button, allowing the front and rear diffs to rotate at the identical speed without slipping.
But the actual game changer got here in 1987 when Audi introduced the Torsen (torque sensing) centre diff. Unlike other systems, this one allowed Audi to repeatedly split the ability between axles when needed. So moderately than sending power 50:50, it could send anything from 25 to 75% to the axle with probably the most grip. That sort of tech seems commonplace now, but rewind nearly 4 a long time and you’ll be able to see why quattro gained such a status in each passenger cars and motorsports.
In 2024, the term ‘quattro’ now is available in multiple variations depending on model and intended use – some you’ll already be aware of, others perhaps not. So, grab a pen and paper; class is now in session.
Inception: When Did It All Begin?
Back in 1976, Walter Treser found himself as the pinnacle of Audi’s ‘Advanced Special Vehicles’ program. One among his earliest tasks was to oversee the key development of an all-wheel drive, high-performance automobile as instructed by Audi CEO Ferdinand Piëch.
The project didn’t actually have a proper name, with the unique prototype model simply often called A1 (standing for all-wheel drive primary). What’s more, no person beyond Piëch and the Audi engineers – including Treser and Bensinger – knew concerning the plan. Especially not Volkswagen.
The story goes that while chatting with Volkswagen’s head of chassis development in Ingolstadt, the engineer boasted to Treser about how great the handling was of their four-wheel drive, off-road VW Iltis, before quickly making an off-hand comment about how good it’d be if the Iltis could have much more power to outshine its rivals.
Hearing this, Treser became more intrigued with the concept of using all-wheel drive in a sporty passenger vehicle, either a coupé or two-seater. Piëch shared the identical view, which ultimately became the inspiration for Audi’s first four-wheel drive production automobile, the Ur-quattro. Ur means ‘original’ and quattro means ‘4’… in Italian.
Nonetheless, the Ur-quattro was almost called something entirely different. Carat – short for ‘Coupé All-Wheel-Drive Turbo’ – was the name favoured by the Audi board, but attributable to this name already getting used by a girl’s perfume brand, it was Treser’s previous suggestion (Audi quattro) that reigned supreme.
Introducing Torsen
‘Torsen’ might sound like one other Audi engineer, however the term actually means torque-sensing. It was this development in 1987 that really revolutionised the way in which all-wheel drive transmissions work.
In the primary Ur-quattro, an open centre differential was used with the power to lock it manually via a dashboard switch. But from 1988 onwards, this was replaced by a Torsen differential – the Type 1 – which allowed engine torque to be sent robotically to either axle depending on which one needed it probably the most.
By default, the split offered a 50:50 distribution, but as grip or traction modified, as much as 80% of obtainable torque may very well be sent to either axle with none need for manual input.
This wasn’t without its limitations, nevertheless. Like a standard limited-slip differential, the Type 1 Torsen is proscribed by the quantity of torque that’s in a position to be supplied to an axle. So if one axle has no grip, the opposite axle won’t be delivered substantial torque, either.
To try to combat this, Audi initially offered the second-gen Quattro with a manual-locking rear diff. Later advances (and a shift to electronically-controlled differentials) meant that every corner of the automobile may very well be monitored to limit wheel spin and permit torque from a low-traction wheel to be passed via the Torsen diff to high-traction wheels as an alternative.
What About Haldex?
Within the case of early quattro systems, Audi used a longitudinally-mounted engine with a centre differential to offer everlasting all-wheel drive, with the power to shift torque between axles with the Torsen centre diff.
But what about those predominantly front-wheel drive Audis? Simply, ‘Haldex’ refers back to the name of the unique manufacturer, and this drivetrain was designed to offer optional all-wheel drive on those front-wheel drive cars fitted with transverse-mounted engines. Think first-gen TT and S3 models, for instance.
To maintain the packaging tight, Haldex uses a multi-plate clutch on the rear differential (moderately than a centre diff) to have interaction the rear wheels, when essential, moderately than being permanently driven like in earlier models. The downside? Due to clutch positioning and the front wheels at all times being driven, earlier Haldex models could only send as much as 50% of the available torque to the rear axle. Because of this – for probably the most part – Haldex didn’t feel ‘properly’ quattro in comparison with the models before it, something Audi addressed later down the road…
quattro ultra
For latest Audis, quattro ‘Ultra’ is what’s commonly used. This (because the name suggests) is one of the best of each worlds, combining traditional torque-sensing with the power to run front-wheel drive without the drawbacks.
Why would you need to mainly run front-wheel drive? Well, Audi found that 90% of driving doesn’t require power sending to all 4 wheels. Anyone who’s seen a dyno graph will know that all-wheel drive saps power, which in turn uses more fuel and reduces overall efficiency.
The answer? Use an electronically-controlled clutch on the rear differential (identical to Haldex) but with one other clutch also positioned on the transmission, disconnecting the driveshaft altogether. In line with Audi, this improves fuel efficiency by nearly 20%.
The fun doesn’t stop there either with quattro ultra. By taking data obtained from the varied sensors across the automobile (including GPS position and outdoors temperature), Audi’s quattro ultra system may even predict when a driver would require front or four-wheel drive without some other intervention needed.
What About The Rear-Biased Audi R8?
To this point, we’ve checked out quattro in transverse and longitudinally-mounted forms. But what concerning the oddity to the range – the mid-mounted, V10-powered R8 supercar? Naturally, this has a novel quattro variation which uses an electronically controlled hydraulic multi-plate clutch.
Due to heavy engine within the rear, by default, the R8 is rear-biased with a split of 85% to the rear axle and 15% to the front. But, when the grip or driving requirements change, an electrical axial piston pump (which might construct as much as 40bar of pressure in only just a few milliseconds) presses the friction plates inside the clutch together, allowing constant variation of torque between the front and rear axles.
In second-generation versions of the R8, this even allows quattro to distribute 100% of obtainable torque to either the front or rear axle. But in the event you really need a rear-wheel drive R8, the R8 RWS built between 2017 and 2018 is your answer. It’s lighter, faster and everlasting rear-wheel drive only.
What’s Your Favourite?
That’s a number of tech to digest in a short while, and we all know this barely scratches the quattro surface before you indicate what we’ve missed. But quattro is Audi’s party piece in spite of everything; this tech not only put them on the map back within the ’80s, but it surely continues to accomplish that even into 2024 with more vehicles than ever boasting all-wheel drive.
Naturally, this prestige has yielded some pretty special quattro editions through the years, from the screaming IMSA GTO race automobile to the Le Mans-winning R18 e-tron. But when we had to decide on only one? We’re going five-cylinder and five doors – the Audi RS2 Avant.
A quick wagon developed with Porsche that also boasted quattro within the early Nineteen Nineties? Even by today’s standards, they’re obscenely cool – and fast.
Tell us your favourite quattro-equipped Audi within the comments section.
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