It doesn't play much of a role on a turbo car, expecially one that spools early and builds boost. On a big turbo car that doesn't spool before 4K it helps but only for off boost light throttle response.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black