I was searching the internet and I came across a site that sopposedly told me how much hp and torque I would get from certain mods. Was just wondering if they were saying that to try and persuade people to buy those parts from them. Are they lying and what will I really get out of them? I was told that AEM CAI will get me 15 hp and 12 lb of torque. Borla Cat-back exhaust would get me 5 to 15 % hp and torque gain and even more if I got a XR-1 collector muffler. Unorthodox Racing ultra S standard belt crank underdrive pulley would gain 5 to 14 hp and 4 to 12 pounds of torque. Greddy headers would add 3 to 4 hp.

 

Well, that site is being a little optimistic on everything except the Greddy headers. The Borla catback may give you around a 5% to 10% increase in power, the pulleys maybe 2-3hp gain, and the CAI is definitely gonna be less than 10hp gain. A lot of times waht these companies do is "cheat" by using differeing methods in Dyno testing. Like when the car is stock, they'd just do a dyno run on it, but when they put on the CAI they take off the hood and put a big fan in front of the car to blow in cooler air. Despite what a lot of companies might have you believing, a lot of the factory equipment on cars is really quite good. Of course replacing it will most likely give you more power, but it's not like it's totally transforming the engine.