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Old 08-20-2004, 08:50 PM   #1
obuerkle
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Default homemade headers?

I have a single port 2.2 liter engine and after much reading have come to the dismal conclusion that its not worth spending much money on the engine.

I am wondering if there are potential gains to be had in fabricating a set of equal length headers (or as close as one can get due to the head design). I can do the work myself so cost isn't going to be an issue. I am thinking that if I go to this level of effort I might as well replace the whole exhaust or at least put in a high flow cat.

The design goal of this project would be to improve the flow path of the exhaust given that pressure wave tuning is not really an option given the head design.

here are some questions for you guys to take a stab at:

1) what size primary tubes should I use? 2" maybe?
2) what length primary tubes might be an intelligent choice?
2) what size should it be after the two tubes merge? I am thinking 2.25"?
3) are the magnaflow high flow cats on ebay worth considering?
5) is this total idea a huge waste of my time aside from the entertainment it provides?

Thanks for the help and or criticism.
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Old 08-21-2004, 02:56 AM   #2
greg donovan
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if you enjoy the work its not a waste of time at all. i cant imagine it would be any worse than stock. and if it was just go back to stock. go for it. and tell us all about it.
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Old 08-21-2004, 04:52 AM   #3
RoadSpike
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Quote:
Originally Posted by greg donovan
if you enjoy the work its not a waste of time at all. i cant imagine it would be any worse than stock. and if it was just go back to stock. go for it. and tell us all about it.
If anything it would gain a small portion of horsepower just off the smooth curves most provide over the roughness of the stock material. The exhuast note on equal length headers should be cool.
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Old 08-21-2004, 05:08 AM   #4
Kevin Thomas
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Quote:
Originally Posted by RoadSpike
The exhuast note on equal length headers should be cool.

Actually, it seems most people like the sound of an unequal length header, such as the Borla. The equal lengths have a distinct sound people would have to get used to or 'grow to like'. It's not a 'ricey' sound but a different sound. I'm sure not everyone agrees but that's the general consensus that I got from reading a good bit of posts on this subject.
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Old 08-21-2004, 08:51 AM   #5
Tigris
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Default headers

Good to see someone is actually doing some custom work instead of bolting on, 2" is way too big though.1.5 or maybe 1.375 might be the best, see how big the head ports are and measure the id of the stock system, bigger is not better as far as na headers go. Use some of your welding wire to measure and "mock up" the bends to get is close as possible.
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Old 09-22-2004, 06:19 PM   #6
obuerkle
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Well my project has slowly progressed to the point where I practiced welding tube merges on the weekend. I also took off the stock header at the head and measured the exhaust port diameter at the head and also the header diameter next to the head, they are both 1.5". I have read numerous times about the antireversion effect of a step up in diameter from the block exhaust diameter to a larger tube diameter. I realize that bigger is not always better but should I increase over the stock diameter to gain the antireversion effect? I am thinking 1.625" (17% area increase) or 1.75" (36% area increase)? Because the first cylinder to fire on each side of the engine is finishing its exhaust stroke and beginning its intake stroke as the second cylinder is beginning to exhaust would an antireversion cone or step be of added benefit in this situation? Does anyone know the primary tube ID of the 2.5 liter engine? Any further thoughts or ideas are welcome.
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Old 09-23-2004, 04:04 PM   #7
DreddRS25
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Might take some ideas from this guy

Well I can't post the link for some reason.

However, there is a thread on this topic that is being discussed on the iclub website. Very cool looking custom headers.
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Old 09-23-2004, 05:02 PM   #8
Kevin Thomas
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Quote:
Originally Posted by obuerkle
Because the first cylinder to fire on each side of the engine is finishing its exhaust stroke and beginning its intake stroke as the second cylinder is beginning to exhaust would an antireversion cone or step be of added benefit in this situation? Does anyone know the primary tube ID of the 2.5 liter engine? Any further thoughts or ideas are welcome.
First off, I wouldn't see how a bigger exhaust diameter at the head would be beneficial. Stick with the diameter piping size of the exhaust port hole.

2nd, anti-reversion I would think would not be an issue on the exhaust side as it would be at the intake side where the valves are. You are going to have a constant stream of gas coming out of the exhaust ports, which wouldn't allow for exhaust gas to be sucked back up into the cylinder. Also, not going with a wider exhaust piping size will keep velocity high so it wouldn't have a chance to slow down to go back up into the cylinder.

That's my take!
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Old 09-23-2004, 06:35 PM   #9
obuerkle
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Thanks for the idea to check out i-club, I think the thread you were thinking of was this one (there were t threads about this linked together)

http://www.i-club.com/forums/showthread.php?t=70988

Coincidentally his design is pretty much what I had in mind, I was inspired by the MRT header for the 2.5. He has some incourageing words with regards to power gains as well, although I intend to incorporate a catalytic converter. I think I'm going to go with smaller tubes though to keep up the gas speed as suggested.

Last edited by obuerkle; 09-29-2004 at 09:11 PM. Reason: bad link
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Old 11-01-2004, 10:10 PM   #10
sha_zapple
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Link no work any update on the progress? im interested!
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Old 11-01-2004, 10:20 PM   #11
Slack
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I'm in the process of working on some custom equal length headers for the 2.2 single port. I have some prototypes made and on my car, but we're still working out the bugs.


Mick
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Old 11-01-2004, 10:24 PM   #12
96Imprezadent
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i think i might try a project like this in the summer since i am just learning how to weld. obeurkle, hit me up with a pm or email me at [email protected] with those diameters and measurements. make sure you remove where it says remove. thanks
-Pete
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Old 11-01-2004, 10:29 PM   #13
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keep all of us 2.2 guys updated....and when your happy with your results, if you don't post a sound clip, we'll all hate you.
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Old 11-01-2004, 10:32 PM   #14
96Imprezadent
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2.2's rule. Unless they are attached to an 4EAT and leak oil from every orafus possible.
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Old 11-01-2004, 10:40 PM   #15
sha_zapple
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What kind of 'bugs' would headers have?
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Old 11-01-2004, 10:54 PM   #16
96Imprezadent
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hmm bugs. well relativly none. if they are done right and the pipe sizing is correct the exhaust stream should be smoother therefore increasing flow and sound resonation. Now with some headers, they crack....i.e. the borlas. I think the single headers will have no bugs at all. But well see.
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Old 11-01-2004, 10:57 PM   #17
obuerkle
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hey guys the project is still underway but has been sidetracked a bit. I am building a pipe/tube bender to make my own bends for the headers and it is about 60% done. I have the frame completed and only have to make the die's to fit my tune. I'll try to figure out how to post some pictures if anyone is interested. I'm getting laid off on November 12th so after that I will have plenty of time to get back at the project. I'll promise to keep everyone updated.

Owen
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Old 11-02-2004, 12:36 AM   #18
Storm
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I like your optimism considering the upcoming employment change! I hope the project works out for ya, there's not alot of support for the 2.2. You may find a good design that others will happily pay to have.
Quote:
Originally Posted by obuerkle
hey guys the project is still underway but has been sidetracked a bit. I am building a pipe/tube bender to make my own bends for the headers and it is about 60% done. I have the frame completed and only have to make the die's to fit my tune. I'll try to figure out how to post some pictures if anyone is interested. I'm getting laid off on November 12th so after that I will have plenty of time to get back at the project. I'll promise to keep everyone updated.

Owen
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Old 11-02-2004, 01:10 AM   #19
Slack
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Quote:
Originally Posted by sha_zapple
What kind of 'bugs' would headers have?
Right now, I am dealing with O2 sensor issues. I will be relocating the bung for the front (A/F) sensor to remedy it. When I get it worked out, I will make a thread about it with pics. I thought that making headers would be rather simple and idiotproof, but I was wrong.


Mick
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Old 11-02-2004, 10:33 AM   #20
sha_zapple
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So im assuming that your eliminating the cat with the new headers? Or am I wrong in my assumption of where the O2 sensor is?
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