Only the wounds caused in that assault count. As a quick rule if it didn't happen during the Assault Phase by units locked in that particular combat, it doesn't count. Turbo-boosting is Shooting Phase.
I dedicate these deaths to Odin Allfather, Spearshaker, One Eye.
Fleet Shadowmaker - Kabal of the Dying Sun; Cult of Marrow Excised; Coven of Lambent Hunger
Sons of the Last Breath - Chaos Space Marines
Host of Shattered Purity - Chaos Daemons