Go looking for the catch if you want but Litchfield’s 572bhp upgrade for the 992 Carrera S and 4S unleashes the wild side in Porsche’s new 911. Words: Dan Trent. Photography: Antony Fraser and Chris Wallbank/Litchfield.
LITCHFIELD 992 CARRERA S
Litchfield can give your 992 Carrera S 572bhp for just a ‘bag of sand
Say what you like about Porsche switching to turbocharged engines but the possibilities it offers skilled tuners like Tewkesbury-based Litchfield Motors are seemingly limitless. With a background in four-figure horsepower upgrades for the Nissan GT-R crowd, Litchfield knows a thing or two about making already fast cars even more so. And doing it properly, with the engineering discipline and resources to ensure you’re not setting a ticking timebomb in your engine bay. Put simply, these guys know their stuff and stand by their work to make those first steps into the tuning world as worry-free as possible.
“You’re basically getting Turbo performance for Carrera money”
This is important as the company moves into the Porsche world, where tuning culture is less prevalent than it is in the Japanese car community, at least for current product.
It’s a smart move for Litchfield, given many owners of GT-Rs and the like find their tastes in cars maturing, even if their appetite for horsepower remains as strong as ever. 911 Turbos are an obvious next step on their car ownership ladder and Litchfield’s toe in the water for Porsche tuning centred on upgrade packages for the 991 generation. The real gamechanger, however, came with the arrival of turbocharged 3.0-litre motors in the back of second-generation 991s, opening the tuning market to any Porsche with a Carrera badge on the back.
This inspired Iain Litchfield’s purchase of his own 991.2 Carrera T, partly because he’d always wanted a 911 but also because he’s a canny businessman with an inquisitive engineering mind and sensed an opportunity. We were incredibly impressed with that car when we drove it a year back in the December 2018 road test and for good reason, a combination of remap and freer breathing exhausts unleashing near-500bhp potential from the more modest 365bhp [370ps] stock output. More than the numbers what stood out was the maturity of the delivery, the sense being that the engine was built for this power all along.
Which, funnily enough, it seems it was. While remaps and extra boost are stock in trade for the likes of Litchfield what shocked him most about Porsche’s first application of the 3.0-litre turbo in the 991.2 was how restrictive it had made the exhaust system. Tubular manifolds, racing cats and a choice of aftermarket backboxes from Remus and Akrapovic released significant extra power before he’d even plugged in the laptop and looked into the engine’s brain, Iain recognising the fact Porsche had quite reasonably left itself considerable headroom for future upgrades. Headroom he readily exploited.
Round two and it’s time to do the same to the 992, the pickings richer still with a deceptively simple sounding plug-in upgrade taking the Carrera S and 4S from stock 444bhp [450ps] and 390lb ft of torque to 572bhp and 480lb ft. Yes, the same horsepower as a 991 Turbo S. Without any hardware changes. Combined with the 4S’s four-wheel drive as seen here and you’re basically getting Turbo performance for a Carrera price before the senior model has even hit the market.
The head start gained from developing tuning packages for the 991.2 meant Litchfield was able to hit the ground running with the 992, given the engine is fundamentally the same but comes as standard with bigger turbos (equivalent to those on the 991 GTS, albeit with a new ‘mirrored’ installation) and freer breathing on both induction and exhaust sides. More sophisticated piezo injection and electronically controlled wastegates also permit more precise fuel and boost control, in a further gift to skilled fettlers like Litchfield. Porsche’s own hardware improvements for the 992 therefore address the relatively restricted nature of the 991 installation, suggesting Iain’s belief the 3.0 turbo motor had been somewhat pegged back in that original application was correct. This time around he simply has more scope to play without any need to change mechanical components.
Without wishing to get too technical Iain and his colleagues have exhaustively tested their maps on their in-house dyno, Iain impressed at how Porsche’s latest engine management is precise enough to maintain the most efficient ‘lambda one’ air/fuel ratio of 14.7:1 throughout the powerband. As a manufacturer it needs this lean mixture to hit ever stricter emissions targets. For tuners less constrained by such requirements and who know how to manipulate these qualities it’s a gift. “An air/fuel ratio that would have previously melted a turbo engine is now targeted across the board because it gives exceptional efficiency and economy,” explains Iain. “You need incredibly sophisticated control of the combustion to achieve that, which Porsche does with its latest ignition systems and works really well. And makes it really easy to get more power. A traditional turbocharged car would only run lambda one on light throttle, shifting to a richer mixture to the point where on full power you’ll be in the low 11s. Because Porsche runs such a lean mixture we can then richen it up, opening the door for more boost and all the rest.” Raising the question, can the rest of the powertrain cope?
“All Porsche stuff is massively over engineered,” says Iain, pointing out that this is still early days in the 992’s evolution, the engine and transmission has been designed through economies of scale to be compatible with whatever more powerful models eventually join the range over the model’s lifespan. Experience with mega-horsepower GT-Rs means Litchfield understands the importance of making sure transmission and other components are up to the job, the pride they take in their work meaning they are about a lot more than easy-win power gains. Suffice to say he has no concerns for the 992 and reckons it will comfortably handle the 600bhp-plus he sees there for the taking with further modifications to exhaust and the rest. In bang for buck terms though an extra 128bhp for £1194 installed seems like a no-brainer.
Where the 991 Carrera T we drove previously benefited from a more extensive range of hardware changes to exhaust, suspension and geometry as well as the remap, the 992 Carrera 4 S you see here is stock bar the plug-in power boost. Which is handily representative of what an owner might want of their first step onto the tuning ladder, given it requires little more than plugging in a laptop and a bit of set-up. That obviously makes it noninvasive and entirely reversible, should discretion require it.
It helps Litchfield’s case that Porsche itself feels confident enough in its latest 3.0-litre turbocharged motor to celebrate its forced induction, rather than try and hide the fact to appease those disturbed by the switch from naturally-aspirated power. Much as the 991 Turbo was more expressive than its more binary 997 predecessor, the 992 seems less afraid about deploying exciting rushes of boost and soundtrack its progress with more extrovert whooshes and chuffs from the engine bay. This is a good thing.
Boost has been increased from 1.2 bar to 1.5 when required but it’s testament to the quality of Litchfield’s set-up work you don’t really notice it at normal road speeds. This sounds like damning with faint praise but the way the upgrade is seamlessly integrated into the standard power delivery is a mark of maturity and the long hours on the dyno, the power and torque curves post-conversion following those of the stock set-up, just with bigger numbers. Which is to say when you’re just cruising about the Litchfield 992 feels much like any other 992, just a particularly healthy one.
You’ll no doubt be familiar with the basics of the car, which is to say it feels bigger, more luxurious and more sophisticated than the 991 it replaces. But still like a 911, the seating position slammed to the floor, the interior sober but functional and beautifully finished and the driving experience just the right side of involving. Some may argue – not unreasonably – it’s shifted a little further down the mature GT end of the scale but there’s just enough of the bob and weave still in the package for it to feel authentic. And sharper than ever.
As in the stock car, things get progressively more aggressive and exciting with each clockwise turn of the wheel-mounted drive mode controller. Wet and Normal dial the response back to sensible levels for cruising and mooching. But life’s too short and Sport and Sport Plus are where the real excitement lies, and where the Litchfield Carrera 4 S shows its mettle.
For a turbocharged engine throttle response is superb and the appetite for revs outstanding. Where most modern motors have given their best by 5000rpm the Porsche flat-six is just getting into its stride, the incentive to keep it on the boil and up in the revs revealed by the instantaneous way it responds to the loud pedal. What the Litchfield modifications bring is a savagery not present in any factory Carrera, setting a pretty high bar for the new 992 Turbo to clear when it does arrive. Because, let’s face it, if the best part of 600bhp is a remap away it’s going to have to do something properly spectacular.
This uprated 4S, fully optioned with PDCC, four-wheel steering and all the Sport Chrono goodies, is a teasing taste of what Porsche may have in store for us. Want to enjoy a thrilling sense of surging boost before stuff goes all blurry? Simply haul in gear from 2000rpm and enjoy the fleeting anticipation of turbos spooling up before that huge mid-range clout is deployed.
Can’t be bothered to wait? Click the left paddle a couple of times, watch the rev needle jump a couple of numbers and, with a few rpm on the dial, the Litchfield enhanced motor is ready with a devastating turn of speed the moment you touch the throttle. For an even more ludicrous hit of acceleration hit the Sport Response button and brace yourself…
The contrast of this performance with the relatively understated surroundings of a ‘mere’ Carrera is genuinely laugh out loud impressive, and this car has a turn of speed that would catch even senior supercars napping. Iain’s confidence the transmission and chassis are built for it already bears out as the roads get twistier and more technical, too, the 992 willing to show its more playful side with a little more commitment by seamlessly combining four wheel steered agility in slow corners with genuine throttle adjustability on the exit.
We’re not talking showboating slides or clouds of tyre smoke. Just the power and torque to really test the power-shuffling all-wheel drive system and mechanical grip of the chassis. A test it responds to with real eagerness and a willingness to tighten its line under power you don’t sense at regular speeds in the standard car.
If you didn’t know better you’d swear this package was a factory upgrade, given how seamlessly it operates with the stock 992 underpinnings. Certainly, it highlights the potential in the car Porsche will deliberately (and reasonably) be keeping a lid on this early in the new 911’s evolution, before unleashing its own more potent versions down the line. For those impatient and unwilling to play by Porsche’s long-term product strategy this simple, plug-in upgrade offers instant gratification and proof this new 911 has a whole lot more to give, both in terms of by-the-numbers performance and (perhaps more importantly) raw excitement.
That Litchfield is able to unlock so much extra potential with such a deceptively simple upgrade is testament to both its tuning skills and the quality of the source material Porsche has provided.
CONTACT Litchfield Motors Highfield Business Park, Tewkesbury, Gloucester GL19 4BP litchfieldmotors.com Tel: 01684 216000
The 2020 992 911 is getting ever more pumped up and muscular and Litchfield’s 572bhp upgrade just adds to that appeal. We love the interior (left), and there’s a manual option on the way next year in the UK. We can’t wait for that! Where the magic happens, or more accurately, the hard work. Porsche’s own conservative approach to air/fuel ratios and boost means that the power is there, it just needs to be unlocked. Left: You can’t really call it an engine bay any more. In fact from this angle, it kind of looks like a ‘boom box’! Anyway, lurking below the fans is a 3.0-litre, twin turbo, flat-six fettled to produce 572bhp. On the road, the Litchfield modified 992 offers a devastating turn of speed, with seemingly no trade offs.