Of all the companies you might expect to build a one-off track special, Kia might not be the first name that comes to mind. But since the launch of the Stinger, with its 365bhp twin-turbo V6 and rear-wheel drive handling dynamics, the Korean manufacturer has been showing its sporty side. The reveal of the Stinger GT420 at Silverstone race circuit was a welcome continuation of that trend, and Petrolhead was there to be one of the first to get behind the wheel.
Even before you fire up the engine, you know the GT420 is something very different. Its aggressive aero kit, which includes a front splitter, prominent rear diffuser and lip spoiler, gives off the appearance of a replica touring car. And then there’s the sound… The standard exhaust has been replaced by a lighter version from Miltek with the catalysts removed, letting the V6 breathe freely. It’s an angry-sounding engine, emitting a baritone growl that reverberates around the stripped-out cabin. You will have certainly never heard a Kia like this before.
The GT420 is far from a stickers-and-exhaust wannabe track car though. No, it’s the real deal. Power has been increased to 422bhp and torque to 413lb ft, while the car has also been through an extensive weight-saving programme. Nowhere is this more obvious than the interior. Gone are luxury features such as the sound system and sunroof, replaced by racing seats, harnesses and a custom-built roll cage. A lithium ion battery saves 22kg; the fitment of OZ Racing wheels a further 5kg per corner. In total, these changes have resulted in a substantial weight reduction of around 150kg.
Out on track, the first thing that hits you is the noise. The GT420 is loud. I have a professional driver sat next to me, but any instruction is limited to hand signals as conversation is rendered almost impossible. Despite the performance gains, in a straight line the GT420 isn’t hugely faster than a regular Stinger GT-S, although it still piles on speed at an attention-grabbing rate. The weight-saving is more noticeable, the lower mass bringing a greater sense of control through the corners. Changes to the suspension, including lower springs and fixed-rate dampers (replacing the road-going car’s adaptive set up), help to sharpen up the handling further, while the car feels much more eager on turn-in thanks to an increased camber angle of -2.5 degrees.
The most impressive element of the GT420 was the braking performance. The Stinger’s front brakes have been uprated, gaining new pads, 380mm discs and six-pot callipers from Brembo. On a subsequent passenger lap with a professional driver, the ability to brake late and deep into a corner was phenomenal. Combined with the grip on offer from the Pirelli Trofeo R tyres, the GT420 is something of a track weapon. The lateral force through the bends gave me quite a workout as I strained to stop myself being flung around in the bucket seat (not always successfully, as you can see in the onboard video below)!
There was always a feeling that there was more to come in terms of outright performance from the Stinger, which is ultimately more of a long-distance cruiser and therefore not fully at home on the track. The GT420 gives us a tantalising glimpse at what a more focused series-production Stinger could be like (although there are currently no plans for such a model). Based on the grin-inducing effects it had during my laps around Silverstone, I’m glad Kia Motors UK chose to save LA66 HTG from the crusher, where, as the first pre-production Stinger to arrive in the UK, it had been destined to end up. Maybe, just maybe, it will convince Kia to give us the hardcore road-going model we now know they are capable of creating…