quaternion sleep (trying to make slower turns?)

hey gang, trying to fix my quaternion.slerp so it slowly turns to face the target, but it spins really fast (doesn't seem to matter if TurnSpeed is 12, or 0.1) its always at the same speed rather then turning slowly turning... if (Target != null) { this.transform.rotation = Quaternion.Slerp (transform.rotation, (Quaternion.LookRotation (Target.transform.position - this.transform.position)), Time.deltaTime * TurnSpeed); }