KIA Insider

Kia Stinger GT420: wild one-off track car driven

Sometimes the answer to a question is very simple and straightforward, such as when we asked Kia why it built the Stinger GT420 track car. ‘Because we can’, came the instant, grinning reply.

Essentially it’s a one-off track car created as a sort of after hours project between Kia UK and the brand’s Engineering Centre in Russelsheim, Germany. Using as its base the first pre-production Stinger GT-S to arrive in the UK, the GT420 has been stripped of weight, given a power boost and had its suspension thoroughly overhauled.

Those at Kia will tell you it’s all just for fun, something they did because they could. But then again, you don’t put this much effort into a project if you don’t intend to learn lessons from it - lessons that might filter down to future, faster models….

What changes has Kia made to the Stinger to make the GT420?

Well for starters the GT420 is around 150kg lighter than the standard car, with much of the weight saving achieved by strippng the interior back to its bare bones. The steering wheel (minus airbag), dashboard, gear selector and driving modes controller remain, but the rest of the interior has been ditched, including the back seats, rear electric windows, the sunroof and the sound system. Installed in the bare metal cabin are a pair of Sparco race seats each with a four-point harness, a bespoke rollcage and, nestling in the spare wheel well, a Lite Blox lithium polymer battery that saves 22kg alone.

Under the bonnet, the twin-turbocharged 3.3-litre V6 now delivers 422bhp and 413lb ft, increases of 57bhp and 37lb ft respectively. These gains have been achieved by tweaking the ECU, plus adding HKS spark plugs, a freer flowing K&N air-filter and a de-catted quad exit Milltek Sport exhaust system. And while the eight-speed automatic transmission is carried over unchanged, there are some tweaks to its mapping and the addition of larger oil cooler to cope with the increased demands of track work.