You don't need to tune for an intake an exhaust.
If I remember right, most cars at wide open throttle use about 80% capacity of the injector. There are a lot of factors that go into timing and ignition, ambient air temp, air density, load, etc...Car's have a base tune that engineers with tape on their glasses figure out with algorithms. Then there are the long term and short term fuel trims. They factor in the outside variables and using the base tune adjust the fuel and air mixture for the best performance.
If you open up the airways of the intake and exhaust, the computer will be able to adapt using the short and long term fuel trims. Most cars are actually rich from the factory at WOT to keep the engine on the cooler side. Guys that really know what they are doing with tuning can piggyback the car's PCM with a fuel controller and either richen the mixture if needed or lean it out at WOT.
Guess I'll stop with my dis-information though because I have no idea what I'm talking about.