Blinx's Official Exhaust Manifold (Header) thread.


blinx9900

Super Moderator
Donator
Joined
Dec 5, 2006
Messages
10,899
After seeing a million threads on this topic and seeing that the users really wanted an official thread for this here we go!

Those of you who have read my past threads know that a lot of my knowledge comes from actual working on cars for the past nine years but some of it is also my opinion and I always do my best to separate opinion from fact so here we go:

Exhaust manifold, also known as:
-Header
-Four branch manifold
-4-2, 2-1, 4-1, etc...
-manifold (though this should not be used as we also have intake manifolds and allows misunderstandings)

Furthermore everything said here is assuming you have a B series engine or other with its traditional exhaust system layout, some D engines have the cat in the header, we will not be talking about that here.

The purpose of the exhaust system is to get the exhaust gas out of the cylinder head, through the catalytic converter and out the back box. The header is the part between the cylinder head and catalytic converter.



Now there are a few different types:

Street Types:

4-2-1(four to two to one):
General:
Possibly the most popular header on street driven civics/integras, just about every company makes them.
Pros:
Usually have great ground clearance, popularity has made them very affordable, and gains are usually across the entire powerband, bolt on installation.
Cons:
None really, this is a great all around header, it’s not the best, its not the worse, 90% of people will love it.
My Opinion:
For your average Joe it doesn't get better than this, this is the type of header I ran when I was NA and I loved it.
Pics:
Possibly the best (and most expensive) 421 TODA Header



4-2-1 JDM TYPE
:

General:
Additionally this header has an interesting variation that there is a JDM version of the 421 that is somewhere between a traditional 421 and a race type 421, companies like Vibrant, T1R, and Honda TWINCAM make these, they have much longer primaries on the 4-2 part.
Pros:
Generally will make more power than the traditional 421, still has great ground clearance.
Cons:
Usually more expensive, usually requires removal of ITR or CTR transmission stiffener, in some cases is NOT bolt on and required modification to cat/testpipe/or b pipe as these generally have a 2.5" exit.
My Opinion:
One of my favorites, if you have what it takes to install one do it! You will often see me recommending the Vibrant 421 JDM spec because I love it so much.
Pics:
Vibrant JDM 421 Header



4-1 (four into one, or four to one)
:

General:
Considered by most people to be best for top end gains, while this is where this header does its best it is not superior in terms of top end gains when compared to other headers. The JDM 98spec ITR comes with an OEM 4-1 header and it’s a popular upgrade for many other B equipped cars.
Pros:
Good gains in upper rpm's, popularity has made them relatively inexpensive, OEM ITR one allows for use of factory heatshield to hide header from police etc, bolt on installation.
Cons:
Horrible ground clearance by design which leads to crushed piping which reduces flow which defeats the purpose of an upgraded header.
My Opinion:
This is my least favorite header, my reason is the ground clearance, I HATE these headers, unless your car is a 4x4 you will most likely crush this header. Okay I'm going too far, if your car is at OEM ride height with OEM or larger wheels you should be OK but there is still possibility of crushing the header on bumps/dips.
Pics:
DC 4-1 Header



Race types
:

4-2-1 Long Tube:
General
:
These are real deal race headers originally designed for race cars, they bypass the catalytic converter and bolt straight to the B-pipe, they are usually very expensive and provide the most power gains as they are usually built for each customer based on there engine setup.
Pros:
Possibly the best for power production as they are built custom for each specific customers needs.
Cons:
Price, deletes cat, and usually requires removal of CTR/ITR transmission stiffener, as this is a race header usually for drag applications they can sometimes hang below the oil pan and have horrible ground clearance. Some of these even require removal of AC and PS.
My Opinion:
These are beautiful headers that are so good looking you may just want to hang them up on your wall and stare at them for hours, if you are considering this type of header you will not need to read this thread or ask any questions, your a die hard racer, you have money, you are well informed and know what your doing.
*Special Note*
Due to popularity off the shelf street versions of this header are now available from many companies like Hytech and SMSP that do not delete the cat and are bolt on but still usually require removal of ITR/CTR transmission stiffener. While not as good as a custom headers they are still great headers and would be considered a step up from the JDM 421 headers like Vibrant. Since these are street versions they generally will have better ground clearance unlike the race versions.
Pics:
SMSP Header RACE

SMSP Street style (notice the shorter design to allow the cat)



4-1 Long Tube
:

General:
These are real deal race headers originally designed for race cars, they bypass the catalytic converter and bolt straight to the B-pipe, they are usually very expensive and provide the most power gains as they are usually built for each customer based on there engine setup and come in more than one variation as seen in pictures below.
Pros:
Possibly the best for power production as they are built custom for each specific customers needs.
Cons:
Price, deletes cat, and usually requires removal of CTR/ITR transmission stiffener, as this is a race header usually for drag applications they can sometimes hang below the oil pan and have horrible ground clearance. Some of these even require removal of AC and PS.
My Opinion:
These are beautiful headers that are so good looking you may just want to hang them up on your wall and stare at them for hours, if you are considering this type of header you will not need to read this thread or ask any questions, your a die hard racer, you have money, you are well informed and know what your doing.
Pics:
RMF Drag Header

SSR Streetsweeper



Side Exit In Either 4-2-1 or 4-1 Configuration
:

General:
Once again these are typically real deal race headers originally designed for race cars and custom built motors but have trickled down to the masses and many off the shelf options are available however as the name implies these are side exit headers that not only eliminate the cat but eliminate the entire exhaust system so if you thought your Buddyclub Spec II exhaust was loud wait till you hear a car with a side exit header! These can exit out either side of the front bumper or even through the hood!
Pros:
Generally will have the most power production as exhaust gas travels the shortest path and headers are usually custom built for each motor.
Cons:
Loud, very loud, as these are race headers removal of AC and PS are often required, modification to front bumper or hood are required depending on exit location, ground clearance may be horrible as its not taken into consideration during design, remember this is a race header for a car that goes straight!
My Opinion:
Balls to the wall here, some people put them on street cars if there states law permits but I think it’s absolutely ridiculous and rude. This is one header that should stay on a race car that goes to the race track only and is never driven on the street.
Pics:
RMF Side Exit Drag Header



Equal Length Headers In Any Configuration
:

General:
This one is a wild card as any of the above headers can be made equal length, they could be bolt on, they could be side exit, they could be 421 or 41, some of the headers mentioned above are equal length.
Pros:
Depends on exact configuration.
Cons:
Depends on exact configuration.
My Opinion:
Depends on exact configuration.
Pics:
See above (RMF)

Personal Note:
Okay, so now we have covered just about all the different header types (please pm me if I left out something) now you may ask which is best for me, well I don't know, I'm not you and if you have read any of my write-ups you will know that I usually do not recommend one part over the other, my purpose is to provide as much information as possible to allow the end user to make the best educated decision for there car. Remember people these are our cars we build, we should decide as individuals what parts we chose, we should do research not just ask "which header is best" as there is no answer to that it all depends on your setup, your states laws, how much balls and money you have, etc... Some people may want a bolt on header, some people may be willing to fabricate while others will sacrifice all comfort for that extra 1-2whp. You are an individual, so please, make the decision based on your personal taste, style, and budget.

Wait I'm not done with my personal note ;) please don't ask me about Chinese or eBay headers, that is not the purpose of this thread. If that’s what you want do your own research on them please.

As with all exhaust products all headers usually come in Stainless and Mild Steel, and optional ceramic coatings, you should know the difference by now of what this all is, if not Google is your friend.

No one design is superior to the next, all headers are great and have there intended application. All purchasers of race headers should assume further fabrication and or removal or modification of parts is required for installation.

See this thread for information on Dyno results:
http://www.ek9.org/forum/honda-integra-type-r/24-headers-dyno-results-stock-integra-type-r-engine.html

**Once again, please do not ask which header is best, do not ask about eBay or Chinese headers, do not ask where to buy a certain header, contact one of the ek9.org vendors to see if they can help you**
 

Last edited:


Cookie

Honda EK 97
Joined
Nov 4, 2008
Messages
219
good work blinx :D, i would add reputation to you but i've been giving you too much points lately gota give some else a go hehe
 


blinx9900

Super Moderator
Donator
Joined
Dec 5, 2006
Messages
10,899
Thanks, hopefully its what people were expecting... That took me over 2 hours to do :(
 


zeff

Member
Joined
Jun 8, 2009
Messages
738
very nice write up blinx...two thumbs up!
 

Last edited by a moderator:

blinx9900

Super Moderator
Donator
Joined
Dec 5, 2006
Messages
10,899
thanks zeff, please don't use my real name on forums though :nice:
 


Joined
Sep 12, 2008
Messages
1,153
good work as always,really doubt you missed any header types,i wasnt even expecting the race type etc to be covered!!
 



Kozy

Bench Racer
Vendor
Joined
Aug 18, 2008
Messages
4,085
I'd to add a little of my knowledge on the subject regarding how the different designs affect the powerband.

The exhaust header geometery is roughly subject to the same gas flow characteristics as the intake manifold, whereby longer runners/primaries improve low end torque at the expense of top end, and short runners/primaries impove top end at the expense of low end torque.

The length of the runners affects the helmholtz resonance within the pipe, which is tuned to a particular rpm band in order to maximise cylinder scavenging. Given that the speed of sound remains constant over all RPM, typically a shorter runner will have a shorter resonance as the pressure waves bounce back and forth over shorter difference, and this will be suited to higher rpm. A longer primary will take longer to bounce pressure waves back to the valve face and as such will be suited better to lower RPM.

This is where the difference between 4-2-1 and 4-1 comes in, the '2-1' section in a 4-2-1 is effectively lengthing the primaries over the 4-1, legthening the helmholtz resonance and thus providing better low/midrange response.

By matching the cylinders correctly in the '2-1' collector you also gain favourable characteristics in how the pressure waves interact with each other, in that the wave from one cylinder will compliment another, as opposed to a 4-1 where you are simply trying to get all the gas out as fast as possible, at the expense of everything else.
 



Mr. Clean

New Member
Joined
Sep 28, 2009
Messages
262
great write up man! wish there were dynos for a b16b lol too picky huh..DOH! :angry2: when i was looking for the vibrant header it only says
b16A... is it the same or any knowledge on what to do wether to get the itr or gsr one?
 






soxturf

Member
Joined
Jun 27, 2009
Messages
635
love the thread brilliant work keep it up i appreciate how time consuming it was !:);):)
 



rvm

admin
Staff member
Joined
Apr 15, 2006
Messages
10,599
Car(s)
EK9/Civic
When I grow up I want to be like you blinx hehehee, thanks for this useful information :bow: :blinx:
 


stevesupernova

stevesupernova
Joined
Aug 25, 2009
Messages
37
Hi gyes i have a problem please help.I know that toda is the best for b16b but...not chep at all too.im thinking for js racing or spoon.i like them both but from js racing i dont have a dyno results.And my other exhaust part is mugen.
 


CSB

New Member
Joined
Jul 1, 2008
Messages
272
Thats a freaking amazing thread Blinx, nice Job.
Thanks for making all this research and knowledge available to all of us.
 


Top