ECU remap

I was thinking about turbocharging a s14 with the KA motor and was wondering what if anything has to be done to the ECU. I read in the FAQ about having it remapped. I was wondering if you could expand on what this is and why?

go with a stand alone. you can't go wrong with it. it will cost a lot and then tuning it will cost more, but it will be worth it in the end. the jwt ecu imo is crap... just get something good like a Haltech E6K or E6X, or if you are loaded on cash then go with the Electromotive Tec3. The complete Tec3 system will run you a little over 2 grand and then your still going to need to pay for tuning on top of that.

If you go stand alone then you have control over every little thing that is going on inside your motor. When dealing with as much power as your going to make from turbocharging your KA, you will want to make sure it's done right the first time so you don't blow your motor.