2018 Milltek Sport MY17 Audi RS3 8V Saloon


MILLTEK SPORT’S RS3 Milltek Sport celebrates their 35th year and we take an exclusive look at their latest project car. Photography Ollie Wildsmith. Words Dan Goodyer.

Nothing sounds like a five-pot turbocharged Audi engine at full throttle. We’ve spent hours watching YouTube in the Performance Audi office, listening to the angry mechanical purr of Group B Sport Quattros and IMSA 90 quattro GTOs. We’ve watched open-mouthed, at Walter RÖhrl kicking up dust at Pikes Peak with huge powerslides, just inches from tragedy. Each and every one has the same spine-tingling five-pot soundtrack. It’s an Audi trademark as familiar as the famous four rings on the grille.

This wall of noise hasn’t escaped the notice of performance exhaust giants, Milltek Sport in Derby. They recently bought this Nardo Grey RS3 Saloon, a car that just happens to have a 2.5-litre five-cylinder turbocharged engine. Perfect for a company that specialises in creating free-flowing high-performance exhaust systems. In fact, Milltek have a history of buying the latest Audi RS on the block, to tune-up and develop a range of exhaust components. With this latest purchase, they’ve bought a brand new car but the sound they’ve unleashed is every bit as spine-tingling as those competition monsters from the ‘80s and ‘90s.Steve Pound, the Managing Director of Milltek Sport explains the extra significance of this project: “We’re celebrating our 35th Anniversary in July this year.” So any project cars in 2018 take on an even greater significance. To stay in business that amount of time suggests Milltek are doing something right. Very right, as it turns out.

The process of developing a state-of-the-art exhaust system begins by analysing the OE components. Steve remembers: “The original exhaust had a primary cat, two secondary cats, a centre silencer and a rear silencer. Despite producing almost 400bhp from it’s 2.5-litre 5-cylinder turbocharged engine, the standard exhaust is fairly restrictive. There are lots of reasons for this of course including cost of production, volume and tone of the exhaust note, etc. We found the original RS3 downpipe was small for the power rating of the car. It would provide a significant restriction if you tried to increase the power output of the engine.

”Steve continues: “Starting at the front, our solution was to fabricate a larger-diameter downpipe. The area directly behind the turbocharger is critical for good boost response, a bigger pipe means lower air pressure behind the turbine wheel, allowing it to move easier and therefore spin-up faster. We exaggerated this benefit by physically moving the primary catalytic converter further downstream. This provides the conditions for better boost control and reduces the chances of heat building-up in the turbine area, which is potentially damaging especially in a tuned engine with high boost pressure.

”Interestingly, Milltek Sport have developed two solutions to replace the OE primary catalyser that contains 650 cells per square inch (cpsi), while the high-flow replacement on this car features just 200cpsi (Milltek system model: SSXAU726). This reduces the obstruction in the pipework but importantly keeps the car legal, capable of passing the ever-tightening MOT emissions tests.

If you are building a race car (or indeed a show car) and therefore passing an MOT isn’t so important, you Audican go for the straight-through ‘de-cat’ version (Milltek system model: SSXAU727), which offers even less restriction. To give you an idea how restrictive the OE catalytic converter is, Milltek claim that a 650cpsi cat typically offers an open area of around 50%. In other words, half of it is bunged-up. By comparison, inside one of Milltek’s ‘HJS’ 200cpsi sports cats roughly 80% of its total cross-section is open to allow gas-flow through. Obviously a complete ‘de-cat’ is the least restrictive of all (and the loudest), but isn’t strictly road-legal in the UK.

Both options use a 3in downpipe and both connect up to the OE cat-back system, or indeed to Milltek’s own cat-back system. Just like the downpipes, the Milltek cat-back is less restrictive than the original exhaust and really opens up the lungs of the 2.5-litre five-pot to let it really sing. The large oval tailpipes are unique to this system, ensuring they fill the apertures in the rear bumper. The whole system is made from T304L stainless steel, with all the mandrel bends made using a state-of-the-art, all-electric CNC bending machine. Equally impressive is the way Milltek laser-scan every part with a Faro arm to ensure perfect fitment. The cat-back system uses OE-spec valves, which integrate with the car’s Drive Select system. So the exhaust is quiet in Comfort mode, but switch to Dynamic and you unleash the raucous five-cylinder growl. It’s quite a soundtrack! And definitely reminiscent of those retro racecars, but the technology here is very different.

The old five-cylinder cars had cast-iron engine blocks, good for withstanding boost but very heavy. In fact, the weight and position of the engine were the main reasons Audi quattro cars of the time were sometimes criticised in the press for suffering from understeer. To prevent this being a problem in the RS3, Audi replaced the cast-iron engine block with an aluminium one. They also specified a hollow-bored crankshaft, anything that would help the engine rotate easier and minimize weight over the front-end.

Milltek Sport have continued this weight-saving. Not only does the exhaust system in this RS3 boost power and reveal the true sound of the five-pot engine, it’s 3.5kg lighter than the original exhaust too. This helps make the already very capable RS even more agile, as it no longer has to move that weight around.

In keeping with their previous projects, Milltek Sport haven’t restricted themselves to simply changing the exhaust. They’ve enhanced that extra agility by fitting a set of H&R lowering springs, lightweight HRE wheels and grippy Nankang tyres. Ollie Wildsmith is Milltek Sport’s Digital Marketing Coordinator. He explains: “We’ve had HRE wheels on previous development cars. They’re bespoke wheels manufactured to a high standard, they have always given a higher class appearance to our vehicles. In this instance we went for a satin finish for a more aggressive look.

”The 20in RC100 wheels are forged from Aerospace-grade 6061-T6 Aluminum, so they’re strong and light. They’re essentially Monoblock track wheels on a road car. They reduce unsprung mass significantly, improving acceleration, handling and shortening braking distances. Plus they fill the arches nicely, which is critical when attempting to build a sharp-looking ride.

People often underestimate the role of tyres in braking performance. The RS3 factory brakes are already extremely effective; huge 8-pots up front with 370mm discs. Their stopping power is boosted by a set of Nankang AS-2R tyres. Ollie adds: “We work closely RS3with Nankang and we’ve had their semi-slicks in the past for the track, which are excellent. This time around we thought we’d try out their road tyres. So far we’re extremely impressed. Considering they aren’t marketed as a track tyre and don’t have the noise or harsh ride often associated with that kind of rubber, they provide lots of grip.

”Simply put, this RS3 looks great. Lowering the car and closing the wheel-arch gaps has had a big impact. The H&R springs supplied by Euro Car Parts only provide a modest drop but it’s enough. We like the subtle colour-scheme Milltek have run through the whole car too. Firstly they specified Nardo Grey paint, which always looks great. The contrast is provided by a black and red theme that runs throughout the car.

Milltek specified the black optics exterior pack, complimented by black badges. They also added to the red exterior highlights provided by Audi; red brake calipers, red detailing on the grille badge and engine cover – with a Red Design Interior Pack and those awesome Super Sport Seats with red stitching. The red stitching continues across the dashboard, matched by red rings surrounding the heater vents. Topping all of wheel this off however, is an extremely sexy Bak Performance carbonfibre steering wheel.

It’s a development wheel that will soon be available to the rest of us. Bak Performance started with a standard flat-bottomed TT-RS steering wheel, which they have custom-trimmed to match the rest of the RS3 interior. The really great thing is that, in addition to looking stunning, the buttons on the steering wheel are fully-functional. So Steve, Ollie or whoever is behind the wheel can cycle through the various options, and of course use that big Engine Start/Stop button too.

This is such a complete, rapid, all-round road car. We’re pleased that Audi decided to release a Saloon version of the RS3. This is the first modified version we’ve come across and it confirms there is so much potential in this model. Milltek aren’t done yet, either. Of course their main aim is to showcase their excellent exhaust systems, but Milltek Sport demo cars have always had a bit more about them too. The next step is to visit fellow legends-in-the-game, MRC Tuning in Banbury to develop some software for the MED 9 ECU.

Some extra fuel should free up a bit more boost which, with some sharpening of the ignition timing, should result in a decent hike in power. Not that it really needs it. The Milltek Sport RS3 Saloon is already an insanely fast road car that, with the valves open, generates spine-tingling noises that echo the legendary Sport Quattro S1 rally car. Sounds like a winning formula to us.

SPECIFICATION Milltek Sport MY17 Audi RS3 8V Saloon

Engine: 2.5L TFSI, Milltek Sport turbo-back exhaust system with HJS 200-cell high-flow sports cat and Cerakote black oval tailpipes

Power: 400bhp

Transmission: 7-speed S-Tronic direct-shift gearbox

Brakes: OEM 8-pot calipers and 370mm discs up front, 310mm discs on rear, factory red brake calipers

Suspension: Standard RS setup with the addition of H&R lowering springs

Wheels & Tyres: HRE RC100 Forged Monoblock Wheels. Nankang AS-2R Tyres.

Interior: Red Design Interior Pack with Super Sport Seats. Bak Performance Audi TT-RS Custom Carbon Fibre Steering

Exterior: Black Optics Pack. Blacked Audi Badges, Nardo Grey

Thanks: HRE Wheels, Nankang UK, Bak Performance, Euro Car Part

Below: Milltek Sport turbo-back exhaust system with HJS 200-cell high-flow sports cat and Cerakote black oval tailpipes Left: 2.5-litre five-cylinder turbocharged engine Above: Bak Performance Audi TT-RS Custom Carbon Fibre Steering wheel “the sound they’ve unleashed is every bit as spine-tingling as those competition monsters from the ‘80s and ‘90s” Top: Bak Performance Audi TT-RS Custom Carbon Fibre Steering wheel

MILLTEK SPORT Based in Derby, which is pretty much right in the middle of England, Milltek Sport build and supply some of the finest exhaust systems available on the market. All their components are fabricated in-house, using state-of-the-art machinery. They also offer excellent warranties on their parts too. They cover the entire Audi range, so you’ve got no excuse.

(01332) [email protected] www.millteksport.com

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Jean-Claude Landry
Jean-Claude is the Senior Editor at eManualOnline.com, Drive-My.com and Garagespot.com, and webmaster of TheMechanicDoctor.com. He has been a certified auto mechanic for the last 15 years, working for various car dealers and specialized repair shops. He turned towards blogging about cars and EVs in the hope of helping and inspiring the next generation of automotive technicians. He also loves cats, Johnny Cash and Subarus.