KA's dont have secondary butterflies. its a single runner manifold. there are a set of butterflies right at the head in the manifold that help low end torque, though.

i had 158hp/159ft lbs in my KA and spent little money to do it. considering stock number on 240's is 136hp/128tq thats not bad.

i had a gutted cat, Apex'i N1 catback, cut up airbox and advance my timing to 21 degrees. i then ended up rerouting my intake to the throttle body side by using some crappy discount auto civic shortram and lenghtening my MAF wiring. that made all the diff in the world top end. the car ran a 15.2 in the 1/4 which is almost a full second faster than other stock ones ive seen.

btw, the car had 215k on it, too!

you dont 'need' headers, but they do a nice job. especially the OBX ones. suprisingly, for the price, they are the best out there.