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View Full Version : headers - 4-2-1 & 4-1 what they refer to...



HRV-80Y
11-10-2005, 08:39 PM
had a search all day at work couldnt find a thread that answers my question...

when people refer to headers 4-2-1 and 4-1

4-2-1 = low-mid range

4-1 = mid-high range

wat does that actually mean ?

i.e. performace increase for 4-2-1 = 1k -4k revs ? n 4-1 +5k revs ?

is there an actual measure of wat low mid n top end is ?

hope i make sense :thumbsup:

locote
11-10-2005, 08:48 PM
i think it all comes down to tuning of vehicle aswell.
heard many stories of how 4-1 you loose botom end but it is gained after tunning plus more at top end

kousoku
11-10-2005, 08:53 PM
4-2-1 means pipes come from all 4 cylinders in your engine, then go into 2 pipes, before joining into 1 pipe which flows through to your muffler.

where as, 4-1, jsut goes from the four cylinders into a single pipe and through to your muffler.

HRV-80Y
11-10-2005, 08:56 PM
4-2-1 means pipes come from all 4 cylinders in your engine, then go into 2 pipes, before joining into 1 pipe which flows through to your muffler.

where as, 4-1, jsut goes from the four cylinders into a single pipe and through to your muffler.

duuur man i get dat part ! :p :p :p

but dats not wat i want explained. fanx newayz

.::F[L]Y::.
11-10-2005, 09:14 PM
well pas, when it comes to deciding which headers to get for your car u gota look at what u want from it. ie 4-2-1 would give you better low-mid range power which is often good for b16a engines as they tend to be sluggish at the lower end of the rev range. For your car which is a b series as well id recommend 4-2-1 to help the revs pik up abit quicker as once u reach mid range your car goes pretty good. Well thats what i reckon anyways

euGeR
11-10-2005, 10:53 PM
4-1's will be slightly more peaky (higher in the rev range) ... but probably barely noticable on a stock engine. When you start moving to high lift cams... you'd probably see a greater peak in power in high in the rev range.

One thing to note is 4-1's will sit much lower than 4-2-1's... that's probably the primary reason why you don't get many 4-1's off the shelf. I'm not talking about the JDM header either...

They'll probably be to low for the street (espcially in a lowered car)

kousoku
11-10-2005, 11:02 PM
lol pas, i was thinking you couldn;t be that noobie =P

but yea,

in a graph of a 4-1 vs 4-2-1, 4-1 will be similar area under the graph, but the majoirty of the gains will be at the 6,000rpm + range. Whereas with the 4-2-1 there should be more gains felt over the midrange between 3-6000rpm, and also slight gains in the 6000rpm+ range.

In some cases, you will tend to experiences losses of power with a 4-1 setup in the low range area, track cars tend to use these 4-1 set ups as they are usualy not going from a standstill very often. Ie, they are generally always in the 6000rpm+ rev range.

DHOCHKG
11-10-2005, 11:50 PM
They'll probably be to low for the street (espcially in a lowered car)


wat bout a integra with stock rim and drop about 2.25' - 2.5' all round..!
any problem..?

cos i just purchase a 4-1 from our sponsor...!
WORRY.. :(

lerroy
12-10-2005, 07:18 AM
its not gonna be that low i wouldnt worry about it

Pas get 4-2-1 as Kous said 4-1 will give you more free flow in the higher rev range
in out b18cs we wanna get as quick as we can to the vtec hence thats why 4-2-1 is most popular for a street car Toda group buy la !!!

HRV-80Y
12-10-2005, 07:55 AM
its not gonna be that low i wouldnt worry about it

Pas get 4-2-1 as Kous said 4-1 will give you more free flow in the higher rev range
in out b18cs we wanna get as quick as we can to the vtec hence thats why 4-2-1 is most popular for a street car Toda group buy la !!!

yeha i was checkn out crsx toda group buy...

i alwayz wanted 4-2-1 just making sure im not getn d nog option hehe

:thumbsup: :thumbsup: :thumbsup: i can c ur buyin sum toda's !

lerroy
12-10-2005, 08:12 AM
yeah im gonna bite the bullet and get some
i spoke to adrian about more power...he said to loose the Xforce :( headers
so they have to go

but yeah Toda :P $1150 such a good price ( from the norm anyway)

Lukezen27
12-10-2005, 07:52 PM
yeah im gonna bite the bullet and get some
i spoke to adrian about more power...he said to loose the Xforce :( headers
so they have to go

but yeah Toda :P $1150 such a good price ( from the norm anyway)

Toda always say that :p

Xforce's are Mugen copys and they look quite good if ya ask me!!

but no one has bothered to dyno em and till someone dose!!! you know Toda make good gains :thumbsup: if ya got the cash spend away

Silly Toda dont make a header for my D :thumbdwn: :thumbdwn:

But I'm happy with my Xforce's till I got turbo then there gone baby :D

lerroy
12-10-2005, 08:02 PM
Well Toda sell both xforce and Toda
im sure that if the todas didnt make great gains for the price you would get ppl complaing and they wouldnt sell..as is not the case.

Toda headers have been proven great gains on many dynos
i will be testing this also with a comparision before and after and i will get back to you

to be honest with the xforce headers i gained 1KW same dyno different day im sure the old saying goes you get what you pay for

anyway not baggin xforce they are a great header....but there are better