Truth.

What about when combined with a Cat back? Is it still 15WHP? If so that is amazing and hard to believe.

With most products you will see the most gains when adding them independently. The more you have done the less you will see from each one.

Agreed, however, couple the NA mods with a decent tune and you'll make significant gains in both hp and tq across the entire RPM range, look what the AP did for bluestyle, shyt was nuts.

exactly, even FIs HFCs only made an extra 5 hp with their CBE already on. Im sure if they had done a dyno with only HFCs it would have gained more. And if they had done dyno of their CBE with HFCs already on they probably wouldnt have the gains that they did with it alone. But I do agree the tune will bring the mods into alignment more and gains some gains.

or all the vendors afraid to show dyno results with only there parts. ;)

i was pulled over and sent in for inspection and the cop shop told me straight headers wasn't gonna cut it so i added some cats (clamped on of course ;) ) and threw out the ticket. man canada sucks it sounds like california only with crappy weather.

Edit: this was the old firebird i wouldn't dream of pulling that shyte in a foreign car here

no emission tests here in Arkansas. i love the south. though i was pulled over one day for driving open headers in my Trans am. got bored and what seafoamin the engine to clear out some carbon build-up. rofl i was making cars beside me vibrate :P