New Audi RS 3 to offer more drift, less lift

We are at the point where the current Audi RS 3, despite its undoubted prowess as a very fast small car, would yield to physics and push the front-end wide, ending the cornering fun.

But this isn’t the current 2021 Audi RS 3. This is the next one – the one due in Australia later this year, and the one with Audi Sport’s RS Torque Splitter differential attached to the rear-end.

Frank Stipfler, Audi’s factory GT3 race driver, tips the new RS 3 Sportback into the third-gear left-hander at crazy speed with the front tyres howling in protest and, just like that, an amazing thing happens.

The next RS 3 lifts its game to another level.

The rear-end swings out gently and predictably, Stipfler applies a dab of opposite lock and mashes the throttle to the floor and the RS 3 just stays there, sliding sideways through the corner, engine bellowing.

He flicks it through a series of bends and it responds like an old-school rally car, loose and easy, with the tail swinging left and right and left again, always perfectly in control.

To check it further, we head to a dry skid pan, and Stipfler does it all again, this time in second gear, and the RS 3 prototype slides sideways and stays there, changing the angle only in response to Stipfler’s inputs.

“The first time I drove it I was thinking, ‘This isn’t how the RS 3 drives,’” Stipfler exclaimed.

“You can just push through the understeer in this mode and the slide will follow. The mode down from this is still an RS mode and it’s the one you’d use for absolute pace on a racetrack, and there are five other modes for more normal driving.

“It’s a huge step forward. You can’t feel the differential doing what it does, but you can feel the effects!”

It’s a triumph of powertrain engineering over weight distribution, and it’s mostly down to one piece of new hardware – the RS Torque Splitter differential.

The RS 3 needed it to make an impact, because the engine and gearbox hardware are largely unchanged.

That means the 2.5-litre five-cylinder turbo-petrol retains its 294kW output (from 5600-7000rpm), but raises torque by 20Nm to 500Nm (from 2250-5600rpm) to throw the car to 100km/h in 3.8 seconds and onwards to a maximum top speed of 290km/h.

The diff technology will allow Audi’s hottest small car, which will arrive in Australia later this year in both sedan and hatch (Sportback) bodies, to be driven calmly, quickly or crazily.

The RS Torque Splitter active differential will use a pair of clutch packs, plus two small metal balls, to help it swallow almost all the RS 3’s enormous torque load.

The outgoing RS 3 uses a clutch pack ahead of the differential, but the Torque Splitter doesn’t. Instead, it’s constantly variable, taking as much torque as the management computer sends to it, then punching it through clutch packs on the left and the right side of the differential.

The clever part is that these packs are opened and closed (so it can send almost all the torque to just one wheel) independently, via small metal balls that roll up and down an angled ramp.

(It’s not the only place this differential technology is used, with the Volkswagen Golf R also using it in its latest iteration.)

“It can’t get 100 per cent [of the torque] on each wheel because of mechanical limitations, but can get 1750Nm on each wheel,” Audi Sport project leader Marvin Schwätter said.

“In theory, we can send all the drive to the rear but in normal conditions it’s variable.

“It’s connected to all the sensors and the management for the engine and the drivetrain and steering angle and calculated with the skid-control and distributed to the rear-end.

“And then the rear is controlled on each side and connected.”

While the diff technology allows the RS 3 to finally move away from its nose-heavy cornering stance, the unsung hero here is a combination of a new, faster CAN bus and a more powerful ECU to match it.

“We have one controller for all the vehicle dynamics. It changes the car depending on what the driver asks for,” Schwätter said. “The time between 90 per cent closed on one side to 90 per cent open is only 120 milliseconds.

“The new ECU is from the RS Q3. The new CAN is much faster and the new ECU matches to it, and there’s also a new ECU on the gearbox [codenamed EQ500].”

In theory, the new technology combination should be able to turn the RS 3 into a wild drifter, at least in its most extreme driving modes.

That’s right. The new Audi RS 3 has three different top speeds.

There is the standard 250km/h limit, and another optional one at 280km/h for cars fitted with cast-iron brakes.

The cast-iron brakes use six-piston Brembo front callipers on 375x36mm discs, while the extra money for the carbon-ceramics buys a 380x38mm disc, plus the chance to hit 290km/h.

The rear brakes on both versions are 310x22mm and they’re only in metal.

The upshot is that the pads are 15 per cent larger in area than on the outgoing model.

Well, that’s what Audi Sport thinks it needs if it’s offering factory-fitted Pirelli P Zero Trofeo cup tyres for the first time.

Audi Sport claims the RS 3 now has 10 times more damping range between soft and hard than ever before, which promises to smooth out the ride.

The biggest upgrade to the suspension package is the new dampers, which move beyond the old car’s magnetic-ride damping and switch to an all-new system.

The standard set-up uses a new valve for the piston, while there’s an optional continuous chassis control system.

“It works like an external bypass valve, and response times for the damping forces is within 10ms,” Schwätter said.

“In the lower speeds we can increase it to 10 times more range, from the widest points of adjustability, from what it was. It has a very good ability to be comfortable and dynamic.”

It’s also a lot smarter about how it uses its dampers, with a new system of three accelerometer sensors feeding triangulated input into the car’s governing ECU to give it a perfect view of how everything is working.

There are seven damper modes, ranging from comfort and eco at the low end of the range through automatic and dynamic and into the three RS modes. It can also separate the damping modes from the powertrain modes in both the individual and RS Performance steps.

Bigger tyres (265/30 R19 at the front and 245/35 R19 at the back) and a trick diff meant more g-forces, so it had to work on the suspension and chassis to keep pace.

Schwätter said the damping system was now all-new, with more negative camber to give the suspension greater accuracy.

“The lower link and wishbone, we have increased the stiffness to get more precise driving when the car is sideways,” he insisted.

“Wider wheels can be a disaster, with more force, so we have to control the higher g-forces.”

There is a new steering knuckle up front, and although the car uses the same basic steering system as the S3, it uses Audi Sport’s own software and power pack to drive it in the interests of “feel and accuracy”.

It has -1.45 degrees of negative camber on the rear and -1.29 degrees on the front, and the body is 10mm lower than the S3 and 25mm lower than the standard A3.