I'm trying to decide if I should buy a header now or wait until after the winter. I've already lightly scraped my stock one and I'm afraid of having one that hangs even lower and scraping\cracking it this winter because of all the pot holes that develop due to snow. Would I feel a decent hp gain by adding a 4-1 header to my current aem cai + dc exhaust setup? (b18c1 btw.)

 

a 4-1 will hang lower than your stock piece. raise your car a little bit and go for it if you have the resources.

 

4-2-1 hangs near stock height.

 

if u get a 4-1 header w/ 2.5 opening u would end up in the 150~160 hp range. itr territory. btw what's the diamter for ur dc exhaust? If i may suggest u get an smsp exhaust ur a custom mandrel bent 2.5 exhaust. Also remember to get the muffler to be 2.5 too. Bottlenecks are bad. The dc will do fine for now, but when u upgrade ur internal like cams/pistons/valves/ ect...a 2.5 exhuast is the best application for it.