Kia Motors UK has turned a Stinger GT S
pre-production homologation car into a “track day monster” called the Stinger
GT420. The name is a reference to the model’s power, which has been
increased from 365 hp in the standard car to 422 hp. The peak
torque delivered by the 3.3-liter twin-turbo V6 engine has also been raised
from 510 Nm to 560 Nm.
It was Kia UK’s
way of saving a pre-production homologation car that otherwise would have had
to be crushed. It was the car used for final testing and tuning in the UK, as
well as a press car that appeared in many UK car magazines and TV shows such as
Top Gear and The Grand Tour.
Impressed by the car’s pedigree and the fact that it
had clocked up an impressive (for a homologation vehicle) 10,000 miles (16,093
km), Kia UK decided to turn it into a track car. With support from the Hyundai
Motor Europe Technical Centre in Rüsselsheim, Germany, the team got to work on
the Stinger420. The list of engine modifications is very long and includes HKS
M45il spark plugs for enhanced combustion, a K&N sports air filter, and a
lightweight Milltek Sport quad-exit exhaust system with catalysts deleted.
The automatic transmission was also upgraded with a
six-row cooler in place of a four-row item to prevent overheating on the track.
Additionally, the gearbox software was recalibrated to provide quicker shifting
characteristic in Sport and Sport+ modes.
To successfully turn the road-going Stinger into a
track car, the team also removed all unnecessary weight, including the seats
and belts, airbags, sound system, interior trim, and rear window regulators.
The engine cover, undercovers, parking sensors, boot and bonnet dampers, and
rear bumper beam and foam were also taken out.
Furthermore, the rear windows were glued into place
and lightweight door cards were installed. Finally, the sunroof was removed and
replaced by a steel panel. In total, engineers were able to cut 150 kg of weight even after the installation of the roll cage, Sparco race seats,
belts, fire extinguisher, and underbody stiffening.
To improve track performance, Kia UK also fitted
Eibach Pro lowering springs and anti-roll bars, wider OZ Racing Leggera rims
shod with Pirelli Trofeo R tires (235/35/R19 at the front and 265/30/R19 at the
rear), and uprated Brembo front brakes, among other upgrades. Rounding off the changes are some
visual tweaks that include a Stillen front splitter and rear diffuser, a rear
spoiler by Air Design, and an eye-catching wrap.
