Ah... I was close.

 

Torque and horsepower are the 2 measurements of power that give acceleration (which is not power). An engine can not have more power to accelerate than it did stock without having gained power, and with an increase in one (hp or ft/lb of tq), 99% of the time you'll have a marked increase in the other, you don't have to pick one. Should that power go up, the engine will accelerate at least a little faster, unless having added the power makes it so you can't control the power and you just sit there spinning the wheel, but that's a different story with several factors that you don't need to worry about.

 

Let me clear this up...
HP is a function of torque. A function is a mathematical model that is applied to a certain, measureable property of a system. Yes, Torque is measured and HP is USUALLY calculated, because of the cost and complexity of a real dynamometer, But HP is also directly measured. The common Dynamometers at speed shops, measure the twisting force (torque) and then CALCULATE a HP rating. However, HP is measured in the laboratory on a dynamometer, which actually measures the temperature increase of a certain volume of water, while it is being "stirred" by the flywheel of the engine, the stirring adds energy to the water, increasing the temp. HP is a measurement of power, which is defined as the ability to do work over time. An engine produces torque, period. Torque is the actual twisting force that the engine produces. The twisting force, is what you feel when you step on the gas and it pulls u back in the seat (G's). HP is just a measure of how much power (work over time) that an engine can produce. If an engine can turn faster (rpms), then it can accomplish more work over time than an engine that turns slowly, get it?
Basically, torque is determined by the displacement of the engine, along with its operating characteristics, (cylinder pressure, compression ratio, cam timing, ignition timing, etc.) the only way to increase torque is to increase either the compression ratio or produce more pressure inside the cylinder, as done by Forced induction or nitrous. HP can be increased primarily by increasing the ability of the engine to "breathe", allowing for more airflow at higher rpms. Of course, only adding air will not add any horsepower, it depends upon cam timing, ignition timing, valve size and configuration, fuel curves, etc.) This is why adding an intake will DO nothing to help your car, maybe adding 1 HP at most. You won't get any noticable improvements unless you add Forced Induction or change the components of the engine.