16-01-2012, 01:08 PM
Less psi is better, flow is what you really want, but thats hard to measure unlike boost pressure. If you put a large restriction in your pipe from the turbo -> TMIC (I.e a load of wire wool or similar, not recomended, thats just an example) then you would probably get a few more psi, but performance would still be down as the air flow is restricted.
Also worth remembering, smaller turbos flow less and they also produce a hotter charge, whereas bigger turbos will flow more at a lower charge temp (because they are spinning slower) Which is why a TD04 at 25psi will be fairly reliable and produce ~160hp with the fuelling to match, and a GT15 at 25psi will be spinning it tits off, producing a very hot charge and only about 130hp.
Also worth remembering, smaller turbos flow less and they also produce a hotter charge, whereas bigger turbos will flow more at a lower charge temp (because they are spinning slower) Which is why a TD04 at 25psi will be fairly reliable and produce ~160hp with the fuelling to match, and a GT15 at 25psi will be spinning it tits off, producing a very hot charge and only about 130hp.