Is there any gains with this manifold compare to stock? Is the gain noticeable, or is it a waste of money

 

going in a 02 rsx-s

 

yes, it will make gains. but for the price u can go with an RBC manifold and karcepts adapter and it'll make even better gains

 

can get one for $300... is that a good deal

 

300 is a very ripped off price for a PRC intake manifol.
u can get an rbc intake manifold with karcepts adapter for 250.
i wouldn't pay anymore than 200 shipped for a PRC intake mani.
i paid 200 shipped for mine, and it came with a used hondata intake manifold gasket.