What do you guys think of a header for my b20? I'm currently running the 90-91 integra manifold (worst b-series E.M. EVER made). It is restricting the flow of my b20 WAY too much. I have the 2.5 exhaust and aem cai. What should i do for a header? I was thinking a 4-2-1 because my greatest power is from low to mid and i thought the 4-2-1 would compliment that but after thinking, the b20 has a greater airflow output so shouldn't i get a 4-1 to compensate? I'm thinking about a 4-1 with a 2.5' outlet. Whaddya think?

 

First of all are you ever going to slap a vtec head on the block? If you are I would go with 4-1 piece, great top end. If your planning on staying B20 I would go 4-2-1, good low end and mid range.

 

Go with the 4-1 header good for top end power , I have the jdm itr 4-1 header in my cr-x..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNDER PRESSURE &raquo;</TD></TR><TR><TD CLASS="quote">First of all are you ever going to slap a vtec head on the block? If you are I would go with 4-1 piece, great top end. If your planning on staying B20 I would go 4-2-1, good low end and mid range.</TD></TR></TABLE>

YUP. depends if you are going to swap the head in the future or not

 

i'm staying non-vtec looking to get near 160-170 whp. The header would be for a b18 and the b20 has a greater output so wouldn't i need a 4-1 to compensate for that?
Also...doesn't the jdm itr header only fit the vtec heads or does it fit the non vtec heads as well?

 

I would go 4-2-1 because your going to stay non vtec, and the crv power plant has no power up top so what you want is good low and mid range.

 

I've got a non vtec b20 in my crx and ive got a greddy 4-2-1. it gets my
if u wanna go 4-1 u might need to modify your cross member plus it'll sit DAMN low (bottom out issues)

 

the thing is...
the b20 puts out a higher airflow output than a b18. I've been told by numerous tuners as well as other people here that a 4-1 header would be better to compensate for the 4-2-1's restrictive design for a b20. I've been told that a 4-2-1 aftermarket header will still restrict the flow of a non vtec b20. does anyone have any experience with both or either on a b20?

 

I run Kamikaze's header in the 2.5in option collector. Makes good power up top

 

well...i just bought a header and a cat. i bought the jdm 4-1 ITR header with a 2.5' collector. The cat is a catco 2.5' inlet and outlet...this will all match up nice with my 2.5 piping and 2.5 muffler. thanx for ur guys help!

 

how big off a difference did it make

 

ill tell you when i get it installed next week. I can install the header myself...but i know ill have trouble lining it up with the stock crx cat because as you know the jdm itr header has a 2.5 collector/outlet. So, i'll have to wait till next week when i can pay to get the 2.5 cat welded up to my already existing 2.5 piping. Then i'll install the header myself.

 

**** welding, muffler cement and a clamp lol

ANyways, whyd you go with the jdm itr 4-1?

Why not go aftermarket? I just thought that header was so high priced because people loathing JDM and didnt think its performance would be any good

 

it's great i think it's the same design as the dc sports jdm 4-1. i believe most of the 4-1 b-series headers are designed after the jdm itr header....i didn't pay that much for it...only $150. i got it because it has the 2.5' collector....which is needed for the b20's displacement.

i really hope u were kidding about the cement and clamp thing....that stuff has no place on my car...i do everything clean and right the first time. i paid $265 for my 2.5 mandrel bent catback from a reputable custom exhaust/turbo shop over here. Some people said they could have done it for like $100 bux or something but i got what i payed for...not some crushed bent, clamped, crooked piping from an inexperienced shop.

 

I got my madrel bent 2.25 for $140 no clamps

Also, you know you can turn around and sell the header and make an easy $100 profit?

My brother sold his for almost 300 worth of parts and I see them going for 250 all the time

 

I really don't want to sell the header...I just bought it....lol