I was just wondering if I could tune a stock ecu on a rx7? So when I get a new exhaust system and couple small mods I could get it running efficient.

 

No they are not adjustable .Doing a few mods you wont have to do any computer adjustments

 

I agree with the above as the ECU is not able to be tuned. The mods that you want to install will not require a tune. The engine will run just fine and the car will have no driveability issues.

 

I'm using a stock S5 NA ECU with a streetport, VDI mod, and RB Street Exhaust, 6-port inserts. putting 165whp (No issues).

 

The FC uses a metered air system to calculate fuel/timing values. The ECU responds directly to the amount of air being moved through the engine via the AFM and pressure sensor. Increase airflow, and the ECU increases fuel accordingly. So no adjustments are needed for basic modifications.

That said, the stock ECU tune isn't the greatest anyway. Power can be gained by leaning out the high throttle areas. There are simple piggybacks like the S-AFC that can fool the ECU by fiddling with AFM readings, allowing some basic fuel curve control.

For what it is worth, the stock ECU can be tuned directly. But only if you are able to unsolder the ROM, dump the file, alter it, program it into a new chip, and solder back. Not practical.