Originally Posted by westcoaststyle
Depends on what all you have done. There are some seriously badass manifolds out there, but you need to be making a good deal of power already to make full use of them.
to back up this post, i'd like to make sure that that this is also stated.
Our car's stock manifolds are designed to flow much more air than they actually flow as a stock motor. Therefor you are able to make some upgrades & not even worry about air flow for a while. Example, sticking a header & an intake on a stock motor is worthless. The only gain would be the K&N style filter due to the fact that it wouldn't be as restrictive, BUT the amount of difference that the filter would make, is not going to be noticeable to the eye or feel of the vehicle so to say.
Hope that helps some of u guys out there.