I want to fab my own header for a mildly modded b16. My goal is to make an unequal length header to get the classic subie rumble. Im not doing this for the preformance gain just the rumble. I was going to start with a 4-2-1 design makeing the top part where it goes down to 2 the unequal length part. Clyinders 1&3 are the longer runners on a subaru by about 23 inches give or take. Currently running a Dc sport header in my Ef with the b16.

What size tubing should i use and what type should i use. Any help or posive input would be great.

 

no, the "subaru rumble" (which is what it seems like he wants) is absolutely because of the unequal length turbo manifold. when you put an equal length turbo manifold on a subaru, it sounds just like any other 4 cylinder. now i dont know how much the turbo plays a roll in this either, or if it will have the same affect without the turbo.

but regardless, it just seems not worth it. you will have extra weight from the extra tubing you will add just to make half the runners longer. just for the sound.

 

It has nothing to do ith the engine. Its all on how the exhaust manifold is made.

Equal length
http://www.youtube.com/watch?v=ejOzvHTplqo

unequal length
http://www.youtube.com/watch?v=re_amuyuLXo

 

im not concerned about the extra half a pound for the headers

 

OK well so far im going to go with stainless steel pipe. The Dc headers are 1" and 5/8 primaries so i will model mine after that.

Is there a better grade of pipe i should go with like 304 or 321?
Which is better for all motor is it even makes a difference and
What wall thickness would be the best?

 

I would just be a little bit more worried about performance then some hunk of metal that you think is gonna make you sound like a subie, considering it is a honda.

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/exhaust-scavenging-101-a-2614040/

exhaust scavenging, better millage, better performance....

a 3" exhaust with turbo spool sounds sounds a lot sexier, then another b16 that rumbles with no punch to back it up.

 

This is one of the stupidest things i have read on Honda-tech.

 

I concur....

 

wow all i asked for was help. I dont need criticizism on preformance or scavenging or on how stupid it is. all i asked for was guidance on how to fab up a header.

 

Why don't you get a cam and have it tuned. It should sound very close.
It would be a lot less work and make your car faster.

 

At least he'd not asking how to put a splitter on a grocery getter, or how to make it more hella flush y0, or how to fab up a Yakima bike rack out of an old shopping cart. FYI my d16 has that rumble to it at lower rpm's, and I like it. I have no idea why it is, but it's not a mech problem. I've swapped injectors, re-checked valve lash, checked compression...it's just how my 4-2-1 turbo manifold sounds.

I am fairly sure it's not so much from unequal length, but more from not properly pairing the cylinders mentioned in your first quote. I've heard some subies that used full-race style headers that paired opposing cylinders together, and they don't have nearly the rumble the stock cast manifolds do. The opposing cylinders are paired since they fire the farthest apart in regards to crank angle. This promotes the best scavenging, and therefor the most power. The stock manifold is one reason subies spool rather slow.


ANyways, the way I'd design it would be to pair 1&2 and 3&4. I'd actually have them merge at the same length (equal length), keeping 2&3 completely parallel until the merge under the engine. IMO that would make the most "rumble".

 

ok thanks. Still need some advice on material to use.

 

Its always easyer to start from something then nothing, get a used header chop it up and re-weld and save yourself alot of time.

What I dont get is, if you have the tools to fab something like this, why waste time on a sound?
Its purely a sound, many hours fabbing could be used to make a turbo manifold or tons of other things to actually make you go faster.

Could just be the kid thing in you, I did alot of stupid **** when I was younger and have learned, but the welding/fab tech on honda tech probably isnt gonna help you out at all, this is the high end area, perfect welds, perfect machining area where people give up design for performance.

Stock GSR sedan, turbo setup 1500$ ish, straight 3" exhaust (no cat, no res, no muffler) sounds like a beast fyi and wasn't even that loud, and I could kill sti's!

Most of the time I see projects like this, its because *you* don't know where to began, and theirs what already kills you, I come up with an idea, look on the internet for 5min to look for ideas and if nothing go out to the shop and start fabbing and playing around and see what works and what doesn't. If this thread would have contained pictures of a project started, stating goals such as sound & performance you more then likely would have been taken seriously but not now, the so called sound you want is even what makes my grandma think o theirs another stupid honda going down the road.

Get in the shop, fab something and post it.

metal tubing, welder, skill.

 

if you want your car to sound like a suby you have 2 options

Buy a Suby

pull out the spark plug to 1 cylinder and it will sound like one

 

Im goin to take a guess. And say it is the way the engine in the SUB idles down from hgher rpms. If you watch your rpm gagues on both cars while listening to the exhaust you will notice it. The SUB idles down a bit slower it seems, createing the "Rumble sound". Its jst like an old pick-up with galss-packs. Only diff, is the packs kackle, the car rumbles. And im goin to have to go along with "The sound might be obtained by a cam", not just a custom header with unequal tubes.

 

EXCUSE ME?? This is the Fabrication forum , most of the posts in here have ZERO to do with Hondas so you don't get to pick and choose who you decide to flame so get the hell out of here and go back to appeareance or where ever the hell you came from.

Please someone just give him the info, help him out- then he gets to post pictures- then I get to see something else beside a god damn turbo manifold.

Also maybe I would love to see a post about a rack built out of a shopping cart, nothing wrong with that. Stop ruining this forum because you guys want to see the same thing over and over jesus,

 

Happens to me all the time when I ask questions. Just ignore the ones you don't like or that have NOTHING to do with your question.

I think it's a valid and interesting question. Sound is important. I get what you're trying to accomplish.

 

I find the information presented here pretty interesting. I love learning how things interact. It doesn't matter why we do the things we do, but understanding what we did is good.

 

Here's a customer's car with an F22C and unequal length manifold.. I believe the runners paired runners are about 6-8" longer than the other paired runners.

http://www.youtube.com/watch?v=hy8UOA-qY1M


Another Honda, but a B18C:
http://www.youtube.com/watch?v=PPnnprvwkRg


Sounds very lumpy compared to other Hondas, but not quite a Subbie yet.. But if you want to exaggerate that type of sound, I am sure you will need about 12-16" of runner length difference to get the distinct rumble.

Sound is very important... I like power, but sound is as much as half the driving experience IMO. A fast car without a good sound is never satisfying. There is nothing wrong with tuning the engine for sound, as most OEM car makers spend tons of money just for that department...

 

QFT!