HEF - Curious if anyone has done any performance-type items to a Hitachi EX120-2. The first thing that comes to mind is to add a turbo intercooler so that on long hot running days, can maintain some type of decent inlet pressure to maintain horsepower. Keep the engine a little cooler also. I see the new units have them. Increase exhaust size for freeer-flowing turbo as well. I see also the newer ZX models now have this.
No. Those more modern systems have those features from the start. They were not added on to improve performance. Your machine was optimized for the technology at the time. Mucking about with it is likely to cause you far more problems than you can dream of. From the pump design to the hydraulic and engine cooling, it is functional as it is. Dink with it at your own risk.