In general will opening up the intake result in more horsepower, but less torque? (I'm talking for any fuel injected car, and opening it the equivalent of simply adding a cone filter.)
I read a theory that the ECM is unable to compensate for the added airflow, and thus runs lean resulting in a loss of torque.

I think that the ECM could compensate by simply adding more fuel. Also, since I'm not talking about forced induction, wouldn't the engine only take in as much air as is optimal for it to run at?

I would love some kind of math, or numbers for proof.

What do you guys think

 

I know for carbed cars, opening up the intake ports can result in the loss of torque, as your are reducing the velocity of the air moving throught the smaller ports. Not really sure if same applies to FI cars (probably, but I'm still a Rochestor 4bb man at heat ) But a head porting & matching cam can overcome this and give you more power.

edit: just think of a garden hose, a smaller hose will have more presure coming out of it than a bigger hose using same facuett, but the bigger hose can flow more volume.

 

When just referring to a cone filter, there's this thing called a mass airflow sensor on the '85-89 V6 cars which directly measures air entering the engine and can account for any amount of increased flow so long as it does go through the MAF

Head/intake porting, cams, etc, are a different story.