Do i have to change my ECU if i have the head swap?
4A-FE Head swap: The head swap is a relatively simple way to increase horsepower in 6th generation ST’s with the 4A-FE engine. To put this project simply: you are taking the stock car removing the FE head and replacing it with a supercharged -GZE or -GE heads (more performance-oriented heads). As the 4A-FE is basically an OEM version of a stoked 4A-GE the block is almost identical to that of a 4Ag. The supercharged heads are fairly cheap and can be found in the US in the 89 and newer supercharged MR-2s. The NA heads are found in the Corolla GT-S and elsewhere. The GE head shouldn’t give you an increase that would really benefit the cost IMHO. This is an option for someone making an all-motor engine, something outside the scope of this topic, so I will focus for the most part on the supercharged (-GZE) head. The way I figure it- a very conservative figure for power should be at bare minimum a 30HP increase over the stock 4A-FE. (looking at the difference between a stock 4A-FE at 105HP a
