what do you prefer 4-1 or 4-2-1 headers?

[jdm-civic]

like title says, im debating if i should buy a 4-1 header or a 4-2-1 header. opinions?

[big mac]

421

[VickNotic]

4-1

[jdm-civic]

any specific reason why?

[big mac]

better flow and almost always give more power than 41 headers

[jdm-civic]

oh ok. any more opinions?

[99hatch]

either way your really only adding about 8hp, so its not gonna be that big of a difference.

[jdm-civic]

im really just trying to get rid of the ugly stock ones

[gerardojdm]

4-1 hearders... Better flow, less restriction than 4-2-1

[97_luder]

N/A 4-2-1, Forced Induction 4-1

[laokid]

421 its easier to install!

[Vteckidd]

All wrong

my 4-1 beats every 4-2-1 it's ever been dynoed against.

4-1 with correct primary sizing, reverse cone is the best design. 4-2-1 isn't bad but generally hurts top end.

[preferredduck]

All wrong

my 4-1 beats every 4-2-1 it's ever been dynoed against.

4-1 with correct primary sizing, reverse cone is the best design. 4-2-1 isn't bad but generally hurts top end.

my exact thoughts, it also depends on what motor you have etc but on my b16 i'll never get rid of my 4-1 because of top end esp 5500 rpm and up. 4-2-1 is low to mid range and i know CTR and ITR's are 4-2-1 but that's oem. after i put my cams in all the other parts really made a difference. what is your main goal and what motor do you have?

[big mac]

he has a single dam more than likly. and i bet he want to get the dc sport 41 header that sale fore like 45 bucks lol

[jdm-civic]

naw its a b16a with a single layer head gasket

[Vteckidd]

b16 id do a 4-1 for sure, you will never make any midrange power anyway with that engine might as well highlight its strengths

[jdm-civic]

but with it being swapped in a ef hatch, would it fit properly?

[Vteckidd]

how would i know what header you are even looking at? lol

As a general rule:
ALL USDM Headers will fit without having to cut the crossmember. USDM headers like Greddy, DC Sports, etc that have a 2.25 in collector

ALL JDM Style headers, meaning 2.5in collector, WILL NOT FIT without cutting your crossmember or running aftermarket traction bars. Headers include Hytech replica, Kiddracing, JDM 4-1 DC Sports or any JDM 4-1 replica, SSR, SMSP, etc

Basically any header that makes power requires you to mod or cut your front crossmember, its really not that big of a deal.

As far as bolting up to any exhaust you have, welcome to swapped EFs. Almost everything will take some form of modification

[jdm-civic]

i wasnt really looking at any name or brand in particular but thanks for the usdm/jdm sizing, ill keep this in mind! yeah i dont really think i want to cut a part of my chassis out for a header that adds like 8hp

[preferredduck]

naw its a b16a with a single layer head gasket

go with a 4-1 for sure you won't be sorry. i have had a couple of people try to get mine a few years ago for a 4-2-1 and i said hell no!!!!