I blew my usdm gsr motor and had a jdm gsr motor put in. After about a month of breaking in the motor. I did a test run and the rpm is not hitting the redline mark or the 8100 mark. Instead it is hitting around the 6000-7000 mark. what can i do to fix the redline? or do i take it back to the shop and tell them to fix it.

 

Is it still running the P72 ECU?

I'm going to move this to Engine Swaps.

 

what kind of ecu should i get and how much is it?

 

You should be running the P72. The price of it depends on the OBD. If it is OBD1, it will be much more expensive than OBD2.