As Litchfield founder Iain Litchfield was fast approaching his 40th birthday, and wanting to add a new GT3 to his fleet, he found that despite his enviable connections, getting onto the list was proving harder than it needed to be. ‘We’re normally able to source most things,’ laughs Iain, ‘But for some reason, that one seemed to be elusive – despite a letter of agreement from a dealer on an earlier 991. It made me think about taking a different tack and perfecting something a little further down the family tree – and when Porsche announced the launch of the Carrera T, it was all the inspiration I needed.’
Quite appropriate really, for a man that’s made a succession of first Subarus, then Nissan GT-Rs, and now supercars perform better than their respective factories could have ever envisaged, it seems perfectly natural to think that the easiest route for Iain to create his perfect 911 was to re-engineer it himself. When you remember he’s a man that can currently count the technical heads of Nissan’s NISMO motorsport division as his co-conspirators, that’s no real leap of imagination.
On further investigation, the idea didn’t even feel like a poor relation of the original plan. ‘I quickly convinced myself this would be the ideal option for me as it was a car I could spec with some of the nice options from the GT cars like the full lightweight buckets, rear seat delete , GT Alcantara steering wheel and a few other choice options,’ Iain enthuses. ‘In fact, the more I thought about it, the idea of a much more subtle car, with some choice mods appealed to me much more than the slightly shoutier GT3. And besides, with my commercial head on, the idea of showcasing enhancements for the Carrera range seemed like a much better business proposition.’
If you’re not familiar with this base specification, the ‘T’ adds a plethora of welcome upgrades and options to the already stellar Carrera build sheet – making it a very different car to drive, even before it’s been breathed on. The ‘T’ feels much tighter and more urgent as it goes about its business, and rewards the driver with sports PSM suspension that lowers it some 20mm over the standard Carrera. The smaller GT steering wheel adds to the general go-kart precision, while the short-shift on the manual snicks rapidly through the gears. It’s not just a short shifter either, the ratios have gone the same way. Add in the sexy seats – or the lack thereof, the lightweight glass, mechanical rear diff, optional four-wheel steering and sports exhaust, and you can see why this car is a truly special machine in its own right. Perfect for those that want to arrive somewhere quickly, without letting too many people know that they’re there. If you squint inside, you’ll also notice that Iain ticked the full carbon seat option, too. In the quest for minimal weight, clearly nothing was too much trouble.
With the car back at Litchfield’s clinical Gloucestershire HQ, and having racked up enough standard miles both on road and on-dyno to set a reliable benchmark or three, Iain’s team turned their collective experience to how to make the car even better. ‘Once I had driven the car, I was convinced that the car just needed an OEM+ style upgrade,’ Iain explains. The car is so pretty anyway, I didn’t want anything drastically different, just lots of tiny detail changes to give the car a fresh dynamic edge.’
Early test runs revealed the car to not only hit its stated 370bhp figure almost to perfection (372, as it goes) on Litchfield’s ultra-accurate Maha twin-retarder dyno, but also, it revealed itself to feel like a car with much more on the road, thanks to the myriad of weight saving options onboard. Or simply not there at all, of course. ‘With the shorter gear ratios, the car felt really urgent,’ Iain grins. ‘That may not be much a headline figure in this day and age, but as a package, it all worked incredibly well. I’m sure it’s no coincidence that Porsche chose to use the engine with the smallest and therefore most responsive turbos for this spec. It’s the perfect, punchy all-rounder.’
The cars first real test at Silverstone with BTCC driver Jake Hill revealed a world of potential, but the need to enhance the soft front spring set up. Under hard braking, the 911’s nose would pitch, lightening the rear, and causing the ABS to kick in too early. Litchfield’s considered fix for this was to commission their regular technical partner KW to create a spring kit to their design that works with both the PSM suspension and lower ride height. With these installed they were able to lower the rear by around 10mm (similar to the GT3 ride height) and bring the front back in line with a 20mm drop. This slight rake not just looking superb, but also giving the car better turn-in. With higher spring rates all round than the OEM set-up, particularly at the front, the 911’s dive was drastically eliminated. ‘The hardest part of this equation was to balance a rate that left ride quality unaffected,’ Iain says knowingly. ‘The result is a car that still has that factory feel – as is comfortable on a long motorway cruise, but so much sharper when switching the dampers to Sport mode.’
Early testing pointed to the suspension lacking under extreme conditions. Litchfield worked with KW to sort
While this may have been enough for many, the work continued with modifications to the front arms, to give a set-up precisely akin to the GT3, with an improved, more direct feel and a much more immediate, self-centring weightiness. The final part of this chassis seeing-to came in the aesthetically pleasing form of custom wheels spacers, again from KW. These improved the track width, improving turn-in further, and giving the car a more direct feel.
Iain was clearly happy with progress so far; ‘We retained the original Pirelli P Zero tyres though out the chassis development and the transformation was remarkable. With the steering perfected, we were lucky to have a certain Mr Harris’s GT3 Touring to compare it back to back - and there is no wanting for feel or precision now. There’s no dead-zone just off centre, just instant feedback and lovely pure connection to the road. The chassis has a neutral handling balance with little to no understeer and oversteer when provoked. It’s a totally different car.’
Everything works in perfect harmony with the factory dynamic mode options - a hallmark of Litchfield upgrades
With a chassis that Stuttgart would be happy to put their top-tier badging on, it was time to find a little more power, and having uprated so many 911s in the past, this was a well-trodden path for the Litchfield team. Ultimately uncorking the exhaust with a combination of parts fabricated in-house, a beautiful Akrapovic rear silencer, and adding their own bespoke ECU calibration would see another perfectly delivered 100 bhp. ‘The only conundrum here was where to sit the torque figure, versus the temperatures the intercoolers can actually work with on these relatively small turbos,’ muses Iain.
Weeks of further testing saw the team settling on a base remap that produced a comfortable 450bhp with 400lbft (up from 332lbft). It was now clear that the turbos were working harder against the exhaust back pressure and generating unnecessary heat. But, as this power level and boost profile drove perfectly the decision was made to effect further hardware changes to improve breathing.
In-house, hand-crafted sports catalytic converters were carefully fabricated, allowing yet another slight ECU tweak. After more careful testing, a totally non-stressed 465bhp and 440lbft resulted. ‘Looking at the data on the dyno and the road it was clear that the engine was running well within itself,’ assures Iain. ‘When you look under the car at the factory exhaust, it was extremely restrictive, especially the manifold design. Akrapovic were claiming a 20+Bhp improvement from just changing the exhaust. It’s almost like Porsche wanted to throttle the flow into and out of the turbos.’
The final piece of the jigsaw was the installation of Litchfield’s own tubular headers that offered an equal length design to smoothly merge just before the turbo entry. These not only added yet more of everything that was needed, but more importantly, allowed the turbos to spool much faster, improving the almost immediate throttle response into something utterly instant. ‘The car now comes alive with any small throttle input and you especially notice it around 2,000rpm, where any car often lives’, a clearly enthusiastic Iain imparts. ‘The free flowing nature of this exhaust allows the engine to produce over 30lbft of more torque at 2,000rpm and another 55lbft at 2,500rpm. The engines response is smoother and more urgent at the bottom end of the rev range and it pulls much harder and crisper at the top end. Overall the new exhaust system increases power to 480bhp and 450lbft.’ Think about that for a second. In a factory lightened car that started with just 370 horses.
A perfect tuning package required the perfect road trip to test. As usual, a pan European dash would be the essential final stamp of approval before the whole solution could be signed off for sale. Here, the hard-worked Pirellis were upgraded to an ‘N’ rated Michelin PS4 set. While they may add a little road noise into this civilised package, the resulting increase in grip was considered to be more than a fair trade off!
What followed was a trip that took in Paris, the Swiss Alps – and all manner of Europe’s best (and worst) roads in a bid to prove to Iain that the car had retained an everyday usability to match its prodigious power and handling. The 7th gear in the trick manual proved its worth across many miles, even showing the 911 to be something of a parsimonious fuel sipper at a cruise. Not what you expect from a car like this. While perhaps not the last word in rifle-bolt shifting, Iain was quick to praise its addition to the car’s easy-to-live-with demeanour. As happy on a ribbon smooth straight as it was on a torturous set up undulating bends, it was clear that the car was ready for its final test – and where we joined it to grab a few shots. It may be a cliché, but there’s a reason that the great and the good of tuning test at the Nurburgring. Its unique set of twists and turns, offering an exclusive set of proving surfaces, corners and braking zones.
As you might imagine by reading this, the car passed its many tests with flying colours. ‘Once we were happy, we put Porsche Championship Wining driver and local ace, Moritz Kranz, into the car for his feedback,’ says Iain. ‘Without prompting he proclaimed to love the steering, and was kind enough to liken it to a gentleman’s GT3, without the edginess or stiffness of the normal GT3. His parting words were that the car remains neutral through the bends without excess lift-off oversteer, offering great power. He felt it would make a phenomenal road car. On the drive home, I had to agree with him.’
Since then, many other luminaries have driven the Litchfield T, proclaiming it to be something of a marvel, enhancing everything that makes the original such a wonderful machine, while adding several additional layers of dynamic ability. ‘It funny really,’ Iain concludes, ‘I set out to buy a standard GT3, but our ‘junior GT3’ is about as good as we could have hoped for. Sometimes not getting what you want allows you to build something you prefer even more…’
Images: Chris Wallbank