This paper examines the impact of wake-grid resolution and turbulence modeling on high-speed steady forward flight simulations of a modern lift-offset coaxial rotor XH-59A. The structured near-body grids are constructed using OVERGRID, and high-fidelity CFD/CSD loose coupling is achieved using the CREATE™-AV software Helios and rotorcraft comprehensive analysis code RCAS. Acoustic results are simulated based on high-fidelity CFD/CSD results and the acoustic software PSU-WOPWOP. The sensitivity of turbulence modeling and wake-grid resolution on nondimensional airloads and acoustics is studied based on four cases: SA-RANS with ∆finest= 10% CtipSA-DES with ∆finest= 10% CtipSA-DDES with ∆finest= 10% Ctipand SA-DES with ∆finest= 5% CtipNo significant discrepancy in airloads and acoustic predictions is shown between the different turbulence modeling cases at the forward flight speeds: 100, 150, and 200 knots. However, the SA-DES model with finest Cartesian spacing equal to 5% Ctippredicted slightly higher magnitude of airloads and acoustic pressure peaks than the same model with 10% Ctipspacing especially at high-speed. An increase of BVISPL up to 4 dB is detected with finer wake-grid spacing.