im wondering how much flow is needed to hit 400+ hp on a 12a... ive been looking at alot of stuff and dont want to go insanely large, been looking at this turbo and others(due to price and availability) but im unsure about the hotside

BW airwerks S256
will flow 60 lbs a min
Wheel Dimensions: Compressor: 55.8 mm inducer, 76.2 mm exducer, with exclusive Extended Tip Technology.
Turbine: 69.6 mm inducer, 61.5 mm exducer.
Housing A/R: Turbine: 1.22, with 'T4-style', divided entry, and 4.21" v-band discharge.

opinions on a direction are greatly appreciated

 

I like that one. Think of it as a GT35R hot side with a T04B/E style compressor wheel.

I think it will work very well with any of the exhaust housings operating at 1bar / 15psi @ sea level.