O.K., I need to enlist some of the help of your gearheads right now. My freind has a 2001 Integra LS and he is really unhappy about the cars speed, or lack of it really. The LS has 140 HP and he wants to intsall an AEM CAI and a some DC Headers, about $500 for the whole thing including parts and labor. How much HP would each add at the crank, aproximately, and would he really even notice a difference in acceleration? Also, how do headers even add HP to a car???

 

http://www.comptechusa.com/images/dyno/2000LSplot.pdf

for the headers only

 

the headers don't ADD horsepower. they free it up. The stock exhaust manifold is restrictive. making it harder for the exhaust gasses to escape, causing the engine to PUSH the gasses out which leads to lost hp. When you add on aftermarked headers, they are better designed and more free flowing making hte engine not have to work to get rid of the gasses. which meas more power to the wheels

here's an analagy. the stock manifold is like blowing really hard through a drinking straw, but when you put aftermarket headers on it;s like blowing through a 1" diameter pipe. Much much easier.