Hi,

If i understand STU lesson very well, no, this turbo is not for your requirement, because efficiancy island is out our 400 bhp.
This turbo is good for 300 / 350 bhp only ( 30 / 35 lb/mn. air flow)

For 400 bhp, it is better to use your first map of GT254OR 76 mm. 48 trim, 0,76 A/R. With this, for 400 bhp, you run with 1,8 bar of TC pressure, you are in good position on Efficiancy Island, and you are just on dotted line.

Regards.

Claude