Standard Turbos and Specs for Imprezas
 

I'm planning to improve the performance of my turbo by keeping it looking standard from the outside but changing the cartridge compressor/turbine/bearing etc. This upgrade would be in addition to a new walbro fuel pump.

The car is a JDM subaru impreza V2 wrx sti gc8c4ed with a standard factory TD05 turbo. I've been looking for a new CHRA with oil lubrication and water cooling but i'm not sure what sizes of compressor wheel and turbine wheel would fit. Also there seems to be a Small 16G and a Big 16G??
=============
"MAMBA Turbo Billet GTX CHRA Cartridge TD05H-16G with 9 blade turbine wheel + 6+6 Billet wheel + 4 holes bearing housing"

Compressor Wheel Spec 48.3 / 68 mm (EVO3 Big 16G 6+6 High Flow Billet Wheel w/ extended tip and Smaller nose OD / Higher Angle to get more airflow)

Turbine Wheel Spec 49.2 / 56 mm ( Inconel / 9 blade Wheel)

=============
https://www.ebay.co.uk/itm/362611298...75.c101224.m-1

COMPRESSOR WHEEL:

48.3 / 68mm (6+6 Blades Billet wheel BIG16G), We also offer GTX 11 blades billet wheel, please let us know if you need to change.

TURBINE WHEEL:

49.2 / 55.8mm (Standard 12 Blades TD05H Performance High Inconel)

=============

To be honest you're wasting your time and money for very little performance gain.
​unless your turbo has failed just leave it alone.