.

In this regard, how does performance exhaust increase horsepower?

It pulls air in and pushes air through. The more air the engine can move and the more efficiently the engine can move that air, the more theoretical HP the engine can make. So, yes, installing a performance exhaust that allows air to move more efficiently can increase HP for that engine.

Beside above, how much HP gain from cat back exhaust? The new exhaust adds two pound-feet of torque and 2.5 horsepower, but only once VTEC kicks in and the engine needs more airflow. That's not a ton, but it's something.

Similarly, you may ask, does Borla exhaust increase horsepower?

Borla exhaust systems are designed to have the optimal diameters and low restriction flow that promote scavenging. The Borla R&D team performs dynamometer testing on new parts to ensure power gains. We frequently see gains in the 8 to 12 horsepower range, sometimes much higher.

Will dual exhaust increase horsepower?

If you have dual exhaust tips to a single exhaust, your vehicle will look great, but it's not doing anything to increase power. Dual exhaust will give you a significant power increase because of the engine's ability to breathe better. Thus, if you are trying to increase horsepower, dual exhaust may be worth the cost.