You can have the great performance and great muffler sound of the isometric layout by changing exhaust manifold only with the stock oil pan layout. You will notice immediately the new exhaust sound and the AT vehicle’s paddle shift gear down feels very cool. You can enjoy the GRB as AT vehicle. The gas pedal response is more sensitive, so it’s much easier to control.

                        HKS Exhaust Manifold                                                                                                                                                                                                     Stock Manifold