Owen Developments offer this "Stage 4" Hybrid K04HTA turbo for the Vauxhall 2.0L turbo Z20LE* engines. These upgraded units are based on genuine Borg Warner K04 turbos, and the standard VXR exhaust manifolds, making these turbos a simple bolt on affair.
Whilst looking similar in it's outward proportions to your original unit, and being able to make use of your existing hardware for an easy installation, this turbo is nothing like your original: For starters, the core is upgraded with a far superior bearing pack that takes high boost in its stride; The Compressor wheel is replaced with the massive, aerodynamically designed, 65mm Exducer, CNC machined and Anodised unit that you see in the pictures; The turbine wheel is clipped, to allow better outward flow at high load; The Diverter valve and Actuator are replaced with the much better Forge items.
These things are good for an easy bolt on upgrade upto around 350hp, whilst retaining all of the responsiveness of the original K04 unit.
Cut back turbine blades to improve exhaust gas flow at high engine load
Owen Developments designed and manufactured 360° thrust bearing kit for increased reliability and allowing for increased boost levels
Turbine and Compressor wheels balanced to a higher tolerance than standard
Lightweight HTA™ Billet Aluminium Compressor Wheel with an advanced aerodynamic profile for unrivalled transient response and efficiency, available in red, blue, gun metal and silver
65mm Compressor Wheel Exducer
Re-profiled compressor cover to take full advantage of the fitment of the HTA™ wheel
Forge Motorsport Actuator and Recirculation Valve