What wastegate would I need for my set up.

.t3/t04 silver surfer .63AR - 350-400hp

what spring, psi, bar??

 

im sure a standard 38mm (or mvs) would work fine. the spring just determines the minimum boost level. most likely you will want to get a boost controller to turn it up to the desired level to reach your hp goal.

what manifold are you using? what wg flange does it have?

 

I have I peak boost ac/ps ramhorn manifold with a 44 mm vband wastegate option

 

Thus I kno ill be getting a 44mm but still spring psi and bar need to be determined

 

psi and bar are just different units of the same measurement. 1bar = 14.5psi

do you plan to use a boost controller or are you trying to achieve the desired boost pressure with just the wg spring pressure?

the highest single spring you can get is .9 bar (13.05psi). after that you need to start using multiple springs to achieve higher psi

spring pressure chart
http://www.tialmedia.com/documents/w3_tial_44_sp.pdf