The way you make more power is by increasing your boost, and adding an appropriate amount more fuel. Just swapping on a new turbo won't change much, except for spool time perhaps. The stock boost on the 1KZTE is probably around 10psi. I'm pretty certain the stock CT12B can support up to 20-25psi. This would be good for another 30-50% more power. So you don't need to upgrade your turbo to achieve more power. The turbo is probably one of the last things you would need to upgrade. You'd first want an intercooler and exhaust upgrade.
Up to about 14psi the computer will add proportionally more fuel, so there is no need to adjust the injection pump or anything else. All you need is a manual boost controller. Beyond 14 psi, you will want to intercool the engine and upgrade the exhaust. At this point you also need a way to bypass the fuel cut that occurs at 15psi. You will also want to adjust the spill control valve on the injection pump. If you decide to do these things, I can tell you how to get around the boost cut etc. I've been running my y LJ78 at the limits of the injection pump and turbo (19psi) for the last four years, and the ECD system is the same, so the same tricks will apply.
I think your first task is to sort out what is wrong with your turbo. You need to confirm what the problem really is. You could ask your mechanic for more details.
Did you buy the truck this way, or is this problem something that has recently happened?
Just to prove you don't need a different turbo to make more power, have a read through this thread. This fellow (also on ih8mud) achieved some ridiculous power with the 1KZTE with the STOCK turbo. He made 152 rear wheel hp and 277 ftlb rear wheel torque!!
Partially ROM tuned 1kz-te
View attachment 1650207
Here are specs of his setup:
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RED is the current tune, BLUE is the OEM tune. I still have some room for improvement but I was running out of time. Also I'm somewhat unsure where the limits are and how to find them. I don't want to blow it up! I will definitely get the area at 2500 rpm raised up into the 275ft/lb range and try to further smooth out a few of the other dips. That will come later, for now I'm going to drive it!
Current mods:
Full 3" exhaust
Front mount intercooler
Re-routed the intake to get fresh cool air.
Techtom Rom board
Manual boost controller set to 17 PSI
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