Header pipe diameter question
 

Im looking into headers for my 930 turbo. will probably go for ghl/b+b. how does pipe diameter affect the performance? im thinking smaller diameter = faster spool up, larger = slower but more flow capability?

my build is as follows

3.3 turbo
8-1 je's
32 carrera heads, flame ringed and twin plugged
964 (or maybe gt2 evo) cams
sds efi
big intercooler
k27 hf2 (maybe gt35)
1 bar spring

does anyone have any recomendations for my engine ?