Other than the typical PC programming.....not much. Cat back exhaust, maybe some aftermarket cams. Most bang for the buck.....find a Ford Lightning 5.4 super charger, along with the higher volume fuel pump. You can find them in a salvage yard or on eBay from time to time.
if you can find the hp. of the eng., you can add between 12-20 more hp. for the headers.
Does not effect engine's output.
yes it can... get royal purple it adds up to 15% of your stock horsepower
In normal everyday driving it will add no extra horsepower. In a racing situation at high rpms it will add some but not much. How much depends on the engine that it is installed on.
There is no easy way to increase horsepower but probably the easiest way is to add a nitros system. Be aware that you can destroy the engine with nitros used incorrectly.
Does increasing the diameter of your exhaust pipe leading from the engine increase exhaust flow and therefore lessen engine burden causing an increase in horsepower? The answer for that is yes, but is negligible. Maybe 3-15 horsepower at best.
Install a computer chip upgrade to improve fuel injection and ignition output. This is the most "efficient" way to add 50 horsepower. The quick and dirty way to add more horsepower is nitrous oxide. Putting the motor on a single-stage NOS bottle will raise horsepower, but threaten the viability of the engine.
190 Horsepower which is stock for this engine. The K&N filter will add almost no horsepower at normal driving rpms. It will help some but only at higher rpms, which is a range that you will not be driving in. These type free flow filters only help in a racing environment, and do almost nothing for day to day normal driving. As to the TB Spacer, it does nothing to increase horsepower. I know you have more than likely been told that they add horsepower, but the dynos do not lie, and they simply do almost nothing for a no-race vehicle.
absolutely. there are many "bolt on" parts that can add ponies or the internals can be modified to get them from within.
Not enough to even notice.
put-up a low pressure turbo charge....
You may not want to do that. the governor keeps your engine below a set RPM limit. going above that too far would grenade your engine. It won't give you any more horsepower at normal RPM's, just the ability to rev higher and generate more horsepower at the expense of engine life.