it has a turbo timer greddy. Is this the electronic boost controller?Well many convert to AWD which is more recommended coz can handle power better and it's what makes Evo special. Fwd with this kind of power will chew up the front tires fast.
Evo 9 stock boost peaking around 1.45 then tapered down to about 1.2. Not sure about Evo 4, I think not yet reaching 1.4 for stock boost more like 1.2-1.3 then maybe tapered down to 1-1.1.
As I said above, if you feel the power now enough and you see the pressure on the boost gauge is stable, then no need to change to external gate yet. Changing to external gate will require taking off the turbo then welding shut the internal gate or remove it completely, then modify either the manifold or O2 housing to install the wastegate, all will cost a lot of money too. If you're just targeting 300+ hp, then just use upgraded actuator like me.
Do you have an electronic boost controller? If no, I recommend you get one like Greddy Profec B v2, or the newer OLED version.
Yeah I will just keep it stock boost