Litchfield Audi RS6 Stage 3 Conversion
If the RS6 in standard trim simply isn’t enough for you, then supercar tuner Litchfield has the perfect riposte. By adding another 200 bhp and a huge helping of torque, the Gloucestershire tuner has created a truly practical, daily-driveable, supercar – with a simply enormous boot.
When Audi created the RS Avant range, it almost made the perfect car. Practical and stylish, yet exclusive without being flashy or pretentious. While the latest RS6 is potent enough for many, for a burgeoning group of owners, it really only forms the basis for creating something even more accomplished. For those lucky enthusiasts, when the thrill of a 552bhp commute becomes too mundane, Iain Litchfield is the man they increasingly turn to, in order to make things better. As a serial super-car tamer and tuner, with Land Speed Records and race championships to his name, Litchfield was quick to recognise the potential in this platform. To capably prove this point, the company’s latest incarnation of its all-new demo car puts out a genuine 750bhp… or put simply, at least 150 more than pretty much anything attainable to come out of Woking, Stuttgart or Maranello.
“The idea for this package really came from our clients,” smiles Iain Litchfield. “A great many of our customers have a selection of supercars to choose from, with their RS6 being their everyday transport. Dozens of them have come to us with a view to creating something a bit more special, but we’ve always rather liked the idea of creating a car that could be all things at once; a perfect family troop transport, an accomplished track machine and an effortless tourer. The Audi RS6 is the perfect blank canvas for that, but with our trademark car being our totally useable 1200bhp Nissan GT-R conversions, our customers rightly expected a little more performance in all areas.
While, in theory, it’s totally possible for our R&D team to create a package that ultimately endowed the RS6 with that sort of power, we didn’t feel that it was the kind of car that needed that kind of conversion. Chatting to our clients, their RS6 is the car they use every single day, as a ‘sensible’ way of getting around. When we set out to improve this car, that easy driveability and docile nature was important to keep in the car. Speaking personally, this is the car I take my kids out in as a family hack, so keeping things useable, sensible and fit-for-purpose over-ruled any headline-grabbing figures. We were always much more interested in the overall feel of the car, rather than the outright numbers. It’s how we always approach the tuning process.”
While that’s an admirable stance, it’s hard to argue that 750bhp isn’t a stellar amount of power for a family estate. For context, let’s look at a few key players. The Lamborghini Huracán has ‘just’ 602 bhp. The Porsche 911 GT3 RS – a scanty 500. Of course, these cars weigh very little, but even when you look at 2.2 tonne heavyweight performance leviathans like Bentley’s GT3-R (which uses the same VAG sourced 4.0 TT engine) , with its grin-inducing 572bhp, then you start to understand that Litchfield really has made the RS6 very fast indeed.
It has achieved this in its usual, efficient fashion, and with a cast of reassuringly accomplished names. After extensive flow analysis of the standard turbos and injectors, Litchfield’s team was happy that they could easily cope with the proposed power and torque figures. Next on the agenda would be improved breathing, as this was clearly where the standard Audi system was strangling the RS6’s potential.
On the intake side, the factory airbox has been removed entirely. To be replaced with a rather smart carbon fibre airbox of Litchfield’s own design. Dyno tests proved this to be able to flow significantly more than the OEM set-up, which would bode well for what was to come. Balancing this new-found efficiency, Litchfield then fitted a full Akropovic exhausts system, allied to their own custom-fabricated 90mm downpipes, which replace the restrictive factory catalysts. The exhaust is a key part of this conversion, as it gives the RS6 an aerobic capacity that the factory, with its need to tick its many legislative boxes, could only ever dream of.
As well as looking much nicer and flowing more efficiently (the exhaust adds decent torque and power by itself), the Akrapovic saves a useful 8kg over the OEM system. It also creates a soundtrack that wouldn’t disgrace itself at the Albert Hall – but we’ll come to that in a moment. Crafted in lightweight titanium, this exhaust system has cast collectors and consists of three silencers. The central version of which features a cross-piece inside, which helps to improve power and ‘tune’ the exhaust note – particularly under full throttle. The valves of the system are designed to open and close in line with the RS’ standard electronics, giving this system the full functionality of the Ingolstadt parts, even if the flow rates and sublime noise that emanate from it across the rev range are anything but! These two components really are key to the Stage 3 conversion, as they allow the car to make an additional 50bhp above Litchfield’s Stage 2 package – which has to make do with a mere 700bhp, of course.
With this new found lack of restriction, Litchfield’s team was then free to move the car to its in-house dyno in order to perfect a software solution that would really make the most of the new components. Keen to maintain all of the Audi’s useful CAN-BUS features (like the immobiliser and interactive functions) but increase control, Litchfield has developed a solution that has allowed them to enhance boost, fuelling and ignition parameters, while maintaining all of the factory failsafes in place. After many miles and hours of dial twiddling and key tapping, the result is a verified dyno trace that now reads 750bhp, with 680ftlb torque… from a factory starting point of 552bhp and 516 ftlb. “In theory, would could actually extract more from this set-up,” explains Iain. “But that would mean running the turbo, fuel pump and injectors too close to their maximum efficiency. At this current level, the whole engine is well within its capabilities, and reliability and longevity are assured. Back to that original brief; we’re not trying to chase numbers, we’re trying to create a family-friendly supercar.” All very sensible… well, as sensible as one can be when designing a 750bhp estate car…
With the powertrain package fully signed off, Litchfield fettled the edges of the Audi’s already excellent chassis with a couple of tried-and-tested upgrades that really make a difference to the surefooted feel of the whole package. A couple of hours spent on Litchfield’s laser-alignment rig has resulted in a minute-perfect toe, camber and caster set-up that means the big Audi can now be placed with the utmost precision on the road, while a full set of Goodridge brake lines give a subtle improvement in feel and precision to the feel of the brake pedal. Allied to race-spec brake fluid, they ensure that the Audi’s stopping capabilities more than keep up with its new-found performance. Currently, the factory rubber provides the grip on this demo car, but with a set of sticky Michelin SuperSports about to be added into the mix, expect the bar to go higher still in future.
Out on the road, the work that has gone into this conversion is immediately apparent. On a micro level, the small suspension changes make a big difference to the crispness of this big estate. The steering is exceptionally communicative for a large 4WD car, and the weight and feedback are just right, with the car feeling very neutral in the turns. During our chat, Iain was keen to point out how much refinement has been applied to the throttle maps on this car, particularly with regard to low-speed cruising and bimbling around town. Here, the RS6 feels no different to its factory forebear. Sure, it’s able to shout a little louder if you want it to, thanks to the Akrapovic’s integration with the Audi’s exhaust control, but if you keep everything in ‘Comfort’ the Litchfield RS6 does a very passable impression of a docile, refined, well-behaved family commuter.
That all changes in an instant however, the second you flick the Akrapovic into shouty ‘Dynamic’ mode and start mashing the accelerator into the carpet. At this point, all 750 horses make it abundantly clear that they’re very angry and willing to gallop – bellowing with a raucous, sonorous holler through those fat titanium pipes. The effect is mind-blowing. This car can pick up its skirts and shovel like no big estate I have ever sat in. Let’s be honest, it’s faster than most of the exotica I have ever sat in too! When asked to do so, the Litchfield car simply squats and fires – with the immediacy and drama of a high explosive device. If you’re going to play at this level, prepare yourself for a visceral assault as your ears revel in that simply delicious exhaust note while your eyes struggle to adjust to how fast the horizon approaches and your brain realises just how fast it as having to think at this velocity. Iain wasn’t lying, it IS a very civilised car, but on a public road, with that much immediate power and that much gut-wrenching torque, it does make you adjust your driving style in order to make the most of what’s on offer. This car isn’t just fast, it can be in the next postcode before your cerebral cortex has had the chance to realise that you’ve even started moving. Not concentrating is not an option when you invite this car to play.
As we approach the traffic lights, the speed is quickly scrubbed off by the impressive factory stoppers – those Goodridge lines giving impressive modulation as the nose squats heavily towards the tarmac – and in an instant, it’s a pussycat again. No barking, popping exhaust. No crackling downshifts. Just a big estate car, happy to pootle to whichever school run, shopping trip or holiday that you need it to. Iain’s right. This really is the only car you’ll ever need. More exciting and involving than a factory-level supercar, yet practical and useable enough to handle the boring and sensible stuff that life throws at us. If your budget stretches to an RS6, and you’re debating as to whether you need a supercar or an estate car as your next purchase, then why compromise? Why not have both? This really is the only car you’ll ever need…
Litchfield Audi RS6 Spec Sheet
Litchfield Audi RS6 Stage 3 Conversion
Litchfield Stage 3 remap
Litchfield carbon airbox
Full Akrapovic evolution
Custom 90mm downpipe
552bhp/516 ftlb – 750bhp/680ftlb torque
Goodridge brake lines
Michelin SuperSports Tyres