i have an STI V5 WRC, still running on the standard ECU with Jap maps and had no problems using Vpower at all.

i was thinking of fitting a decat downpipe with an uprated fuel pump (walbro255) and a fuel press regulator. would this be ok?

also can i fit ported headers as well, will this make a difference?

finally as the decat will increase boost will i need something like an apexi avcr or blitz boost controller?

the big question is can this be done safely without a remap? has anyone done these mods on a JDM?

 

I wouldn't; wait till you can afford the remap and get the lot done in one go. At the very least I would recommend you get a knocklink so you can monitor for det as you mod. Really though, you'll need that remap, at the very least you won't get the optimal gains from your mods without it, at the worst, you'll end up needing a rebuild!

Ns04