Did dyno
Then put on spacer, two days later did dyno.
Put on Z tube and filter, 3 days later did dyno
All within 3 weeks on the same dyno
No service inbetween.
In the end i got an exrta 15rwkw
I gave time between mods so the computer can adjust, Thats what i've been told needs to happen or you can reset the ECU for quicker results.