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Old 05-02-2001, 06:53 PM   #1
kapnk
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Post sweet n/a header

Very nice jdm ss header. costs about $1100 b4
shipping from japan. drool.

<IMG SRC="http://www.flatt-racing.com/media.html/imp-ex.html/photo3.jpg" border=0>
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Old 05-02-2001, 07:07 PM   #2
Keiho
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Those kinda look like equal length headers..can anyone confirm?
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Old 05-02-2001, 07:14 PM   #3
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i would say most definitely.
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Old 05-02-2001, 07:16 PM   #4
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Very nice. I wonder why Borla has to make the header off the passenger side make that big line across the front of the engine?


<IMG SRC="http://www.cobbtuning.com/images/borla-header2.jpg" border=0>

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Old 05-02-2001, 07:16 PM   #5
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which company makes that header?
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Old 05-02-2001, 07:23 PM   #6
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Old 05-02-2001, 07:29 PM   #7
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sharp curves are much worse than length of pipe. That first header has an almost 180 degree bend in the passenger side pipe where it meets the cat.

I think you'd likely find you get equal, if not more, flow from the borla design than that one.
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Old 05-02-2001, 09:15 PM   #8
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primaries on both systems look kinda short to me, imo. Borla's collector is much more inexpensive to fab compared to the other ones. Not that their's anything wrong with that. Collector design along with exhaust design is not a science. Maybe easier to make is better for power. ? If I win the lottery tonite I will make an attempt to answer these questions
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Old 05-02-2001, 11:37 PM   #9
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Quote:
Collector design along with exhaust design is not a science.
Hehe, if you only knew...

It jsut about takes a degree in geometry, physics, harmonics, and machining to make a perfectly tuned header, intake or exaust. There is alot of variable to it. Length, diameter, number of bends, back pressue. They all factor in. Its not such a big deal on a turbo car. But a N/A car is very VERY picky about tuning. And depending on how the engine is setup, there is a very fine line you can ride for your intake and exaust. Unfortunatly, there is no "perfect" solution for all around. There is an average setup...but we all know what that feels like.

So believe it or not. It is a science...a very big, complicated science.
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Old 05-03-2001, 05:34 AM   #10
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It looks like the first header pictured is an equal length setup. You guys were talking about how bad it is to have sharp bends in the metal and how that restricts airflow.

Which would be worse? An unequal length setup with not to drasstic bends or an equal length setup that has one fairly drastic bend near where it hooks up to the exaust? I'm sure the engineer designed both of these setup with certain bends and other airflow restrictions to make sure the exhaust from both sides reaches the end of that header at the same time and at the same rate. Otherwise wouldn't it create backpressure?

[This message has been edited by MY99 2.5GT (edited May 03, 2001).]
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Old 05-03-2001, 06:41 AM   #11
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I would agree that the collector where the right hand bank joins in is so horribly designed that this header is not worth $1100 plus shipping. It also wouldn't surprise me if it performed worse than the Borla.
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Old 05-03-2001, 11:18 AM   #12
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The crux of the biscuit, as others have mentioned, is that that there is an almost endless supply of variables that affect intake and exhaust flow. There are general rules of things you should avoid, such as unequal lengths/sharp bends/drastically changing pipe diameters, etc., but even these can be worked around if you can't avoid them. Application specific trial and error is the overriding principle. This is why I cringe everytime somebody goes off about how easy it was for them to build their own intake/headers.

The only single inviolate rule is that nobody can tell you how a header is going to perform just by looking at it.
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Old 05-03-2001, 11:22 AM   #13
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Oh, also, equal length doesn't necessarily matter. If you look at the borla design, the passenger side pipes join together almost immediately, while the collector on the drivers side is much further back. This would result in the exhaust on the passenger side flowing much quicker, and cancelling out the problem caused by uneven length. They have engineers design these for a reason .
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Old 05-03-2001, 11:26 AM   #14
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I define science as being able to understand and predict in an area or subject. Exhaust design is far from being predictable or completely undertsood. It is still stuck in theory. No one really knows what is happening when you tune an exhaust. It is exhaustive engineered controled testing, experience and imagination. Having spent the last 11 years imersed in exhaust design, testing and fabrication for 2 and 4 stroke engines I have a feeling of what is out there. I also have some technology in tube forming and exhaust tuning to make the next step in gaining more power with exhaust. The area needed is to combine a complete package with intake tuning, valve timing combustion chamber, ignition and exhaust to raise the bmep of the 4s motor. It must be tuned as a complete system.

I welcome all thoughts on this. The more I learn about exhaust tuning the dumber I get
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Old 05-03-2001, 01:42 PM   #15
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borlas designed to meet CARB specs, which means they attach to stock cats, that's the #1 reason they are the way they are.
AO
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Old 05-03-2001, 03:33 PM   #16
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But does the Borla header actually have CARB certification?
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Old 05-03-2001, 05:59 PM   #17
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I didn't know it needed one.
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Old 05-03-2001, 06:16 PM   #18
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Honestly I don't know if they do, but they're primary design factor is to maintain stock cats, otherwise... you'd be doing something very illegal & costly (possible 10k fine for removing your cats) Did I mention that I'm getting the MRT exhaust which does just that. Thought it's legal as my car is for track use only
AO
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Old 05-03-2001, 08:15 PM   #19
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WOOW! Just what I'm looking for! There's just one thing, I don't have the money to pay for it. CRAP!
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Old 05-04-2001, 05:26 AM   #20
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Am I wrong, but isn't it by definition that a "header" is equal length to be called a header in the first place? The exhaust manifolds are what are not equal length and not classified as a header.
Mike
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Old 05-04-2001, 06:15 AM   #21
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Aaron, the MRT exhaust does have a cat, so although it is technically illegal, at least we won't be completely thumbing our nose at Mother Nature. Actually, now that I think of it, my car has over 50k miles on it and I'm pretty sure my cat is "broken" , so I think it needs to be replaces. Yeah, that it's!

Mike, a "header" just has individual pipes for each exhaust port, they aren't necessarily equal length. Of course, even a manifold has individual pipes for each port, but the pipes all dump into a common manifold as soon as possible. I guess that's how I would distinguish a header from a manifold - the manifold combines everything as soon as possible, while a header tries to give each cylinder room to breathe. (Very scientific, eh? ) Anyway, if you go here http://www.bassani.com/headers.htm you can see an example of an equal length and unequal length headers for a 5.0L Mustang. Those equal length headers may look like a twisted hornet's nest that couldn't possibly be efficient, but they actually do make a bit more power and torque on the dyno compared to the unequals. Not enough difference for me to justify the burned spark plug wires, the greater installation difficulty, etc, so I stuck with unequal length headers. Next up is some good equal length long tube headers, but that's not important right now.

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Old 05-04-2001, 11:43 AM   #22
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oh, I know it has a cat, just not the stock one which is only semi illegal. What ever...
AO
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Old 05-04-2001, 01:57 PM   #23
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I have no idea how most cars are designed in this respect, but it seems pretty dumb to me that the header pipes go into the cat at a 90 degree angle to the midpipe. If they went with the flow of the car (front to back), you wouldn't have the near 180-degree bend in the first header (and in our similarly-designed stock headers).

I know you can get aftermarket hi-flow cats, is that one of the things that is changed, or does the setup stay the same? Someone should manufacture a header/cat combination that fixes this problem.

Marc

edit: I just noticed that in the first picture the header has something on the right pipe. What is that? btw, I have the Borla ones on my car, and I'm very happy with them so far.

[This message has been edited by Marc Sawaya (edited May 04, 2001).]
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Old 05-04-2001, 05:58 PM   #24
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that short piece is a flexible joint or coupler. It just allows some free play so the motor does not shake/vibrate the sytem apart. I many cases exhaust design simply comes down to "plumbing" challenges even if hi-perf systems. It's because of those darn fenders and stuff
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Old 05-04-2001, 11:44 PM   #25
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That thing on the secondary pipe is a flex joint. It is commonly used to make a pipe easily bolt up to something that otherwise could not without it. In this case, it is probably used to prevent cracking and to give the header a little play. I doubt it gives it too much play or they wouldnt be a leading header company in Japan. But that's what it is. It's only a flexjoint. It's not a cat or anything, and I doubt it's restrictive at all. Peace Out
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