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Exhaust Manifolds for D-series 1988-2000

Supersprint
two options outputs, part number 920 301 (45mm)
921 201 (60mm)


Iresa C29TE29 60mm output


Fujitsubo part number ? 50.8mm output


Mugen XE4-18100-KOSJ output ?

thx indeed for this - i might be designing my own header close to Supersprint
part number 920 301 (45mm) but ill have to find out how much wide the exhaust ports should be for more power from the head for my build, and im not sure if ill get a ready modified head or a y8 head or stay on the same head ...

one thing for sure is ill be designing a header for sure

never knew this info btw its a first 2me - thx alot betek -

cheers man

for a mild set up you can work with almost any 4-2-1 ebay header. It will do the work.

I think our D14s are revving funs because they have the stock rev-limiter on 7200 and until there they pulls, with no power fall.
Also we can see that the stock header from factory is 4-1.
For this reason I think the optimum header must be the 4-1 like the b18c style that help to have better exhaust flow at high revs!

On the other side the D16s have lower rev-limiter and their strength are on the middle revs and that's why they have 4-2-1 from factory.

Now someone can ask if 4-2-1 headers are useless for D14s?
The answer is no, if our target is more torque at the low to mid revs and we don't care to increase the stock rev limiter.
But the optimum for happy revving D14 engine is the 4-1 header B18C style with reprofiled camshaft or aftermarket one for revving purpose.

Also someone can ask and why there are many 4-2-1 headers and hardly no 4-1 headers?
In my opinion the answer is the that large US market have D15-D16s engines and for these engines the most suitable headers are the 4-2-1 ones and the aftermaket companies will not deal with little market of D14s! And that's why they don't make 4-1 headers.

guys , so i herd that the 4-2-1 hearder gives around 7hp but with my carbureted car i think it will give less ( i dont know ) since my last tune on the carb - i still havent dynoed the car but im not driving the car its just parked in my parking bcoz the dyno shops are so expensive here -- one session is for around 200$ so im just building a virtual build and when im done with my virtual build ill start getting the things .. anyway

my question is how to test the header - meaning if i would design a header ..how do i test how much power it will give me ?
any idea ? i was thinking of a water flush method to test a couple of headers for flow hehe but im just inventing again - i dont know.

how do they test how many hp does a header give .. what do they use?

sktaroins wrote: my question is how to test the header - meaning if i would design a header ..how do i test how much power it will give me ?
any idea ?
how do they test how many hp does a header give .. what do they use?

Dyno run before fitting, then dyno run after fitting!simple

the stock 4-1 header is only made for economy. The design is way beyond 4-1 aftermarket ones. The d16z6 header is a good choice and don't care about the 4-2-1. It is way bigger than stock so it will do the work. I have a 4-1 dc but to tell you the truth I don't think it makes any difference than any other 4-2-1 in this stage of tuning. Sam get a used stock 4-2-1 from d16z6. It will be just fine. Remember that with 4-2-1 you don't change the place of the stock o2 sensor which is a great deal.
John d16z6 is powerful in mid revs not due to the header but for other reasons (cam, displacement and engine design)

done - ill look for it in the market - so its almost the same shape as stock but just bigger right?
how much hp will it add?

iam not looking for big difference - just a bit.

it's not like stock its 4-2-1 and its big

Have a look here
http://mycomputerninja.com/~jon/hondain ... index.html

is the civic esi (d16z6) exhaust header plug and play with the back side of the exhaust (from the cat to the back box)??
how small can be the gains by using such a header...