I currently have a 04 STi with Ecutek and TBE 3" dynod at 280 whp @18 psi of boost. Stock the car dynod 237 whp. Can I hit 350 whp or 400 flywheel with a 20 G turbo bigger injetors and bigger fuel pump? of course with a retuning of the ecutek to go along with it? Can I hit this target with a 20 G ?

I'd like to know as well, I have a 20g setup waiting to be installed. I don't think 350whp is possible on pump, but i hope to be proven wrong. 20g will flow 200cfm more than the stock vf39, so it will be a good improvement. Are you staying internal wg?

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I currently have a 04 STi with Ecutek and TBE 3" dynod at 280 whp @18 psi of boost. Stock the car dynod 237 whp. Can I hit 350 whp or 400 flywheel with a 20 G turbo bigger injetors and bigger fuel pump? of course with a retuning of the ecutek to go along with it? Can I hit this target with a 20 G ?

All you need is another 40hp or so to get to 400 at the crank; the 20 G should be good for that, with the proper mods and a good tune. OTOH, 350 to the wheels? I don't think I've seen a 20G make that kind of power on pump gas...at least not on a mustang dyno. About the best I've seen is around 325-330whp. But that is way over your crank number.

Maybe if it were externally gated it might do it...