does any b series header will fit on a b18b? it doesn't matter if its a gsr or a type-r? also what header is best for power on high rpms the 4-1 or 4-2-1?
thanks

there must be ten categories on this subject already. just look through what everyone has said.

you can look at some other posts but i will go ahead and say what i know or what i have read other times. any B series header will fit. there might just be a difference in the length of the header so it might not meet up with the rest of the exhaust like it should therefore might have to have a little material or something added. if you really want some gains with the header make sure it has a 2.5 inch collector.

It has long been promoted that a 4-1 was best for top end while 4-2-1 was better for mid-range, but I think that is only true to some extent. Like if you're buying generic headers. I notice that pretty much all the high-end expensive shop-fabricated headers that make huge power are 4-2-1. The power is all in tuning the length & diameters of the piping.

I agree but the standard for power is that the 4-1 is for top end and the 4-2-1 is more for mid to low end power. Honestly I can tell you that I put a DC 4-1 on my old B20 and a Tsudo 4-2-1 the same day just for comparison and I couldn't tell much of a difference. Now after I installed the ITB's and 404's and then did this same thing I could tell a hell of a lot of difference. The 4-2-1 kind of choked it out on the bottom and really felt like it took power away while the DC 4-1 felt great all the way up. I guess the moral of the story is that in order to feel the difference every component on the engine must work together.