You'll win with even drivers, but don't forget it's not just the few extra horses the exhaust releases in the Mugen Si, but the suspension is a special 'track' setup, but would increase times in a straight line as well.
Ex. Mugen Si with stock FA5 suspension vs. Mugen Si with Mugen Si suspension
assuming equal drivers, equal conditions etc. only difference is suspension, the Mugen Si with the Mugen Si suspension would win.
