Don't open it up, just run it, and if it's too noisy maybe think about some baffles.
That pic was just an example, you only need a big area change to terminate a wave, hence why it's called a termination box.
Weber DCOE 45 rich phase
Moderator: Team
Re: Weber DCOE 45 rich phase
Yes, from a performance standpoint the baffles only serve as supports to keep a flat-sided box from oil-canning itself to death. (ask me how I know this... 
)
)Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
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leebrignull
- New Member
- Posts: 36
- Joined: Thu Dec 17, 2015 9:23 pm
- Location: Christchurch, New Zealand
Re: Weber DCOE 45 rich phase
Ok guys back at work now and should be getting an old CAT tomorrow, just one question though, how come I plumb this in at the second length at around 35", rather than the first length at 18.6" ??
Also I cut the 3rd "Y" off the headers to shorten the secondaries and think I also found a problem there that could be contributing to the reversion, the pipe on the outlet side of the Y, was pushed about an inch into the Y before it was welded in place ! so obviously one hell of a non flowing path for the exhaust gases to try and escape out of the Y into the main pipe.
I had no way of checking the 1st two Y's as too many bends to get a look down, so incase they were manufactured the same I cut those off to check too, they were not as bad though as only poked through slightly into the Y junction.
Am having a exhaust shop flare the ends of the main pipe and secondary pipes to the same diameter as the Y' outlets so there will be no step, and will then mount it all back up and weld in place.
Getting there....
Lee.
Also I cut the 3rd "Y" off the headers to shorten the secondaries and think I also found a problem there that could be contributing to the reversion, the pipe on the outlet side of the Y, was pushed about an inch into the Y before it was welded in place ! so obviously one hell of a non flowing path for the exhaust gases to try and escape out of the Y into the main pipe.
I had no way of checking the 1st two Y's as too many bends to get a look down, so incase they were manufactured the same I cut those off to check too, they were not as bad though as only poked through slightly into the Y junction.
Am having a exhaust shop flare the ends of the main pipe and secondary pipes to the same diameter as the Y' outlets so there will be no step, and will then mount it all back up and weld in place.
Getting there....
Lee.
Re: Weber DCOE 45 rich phase
You've got 1.750" pipes when you should have 1.43, and if you make a higher VE they have to be smaller again. I think those steps were helping you by artificially shrinking the pipe to the right diameter.
Re: Weber DCOE 45 rich phase
35" is just a good safe guess.
There are multiple "working theories" on how to tune headers, and they do not all agree, but in this case most of them agree 35 is a good bet, and I think it should work OK if the rest of the header is right or not.
Schools of thought which would support 35" collector:
The OLD short primary type tri-y header theories, A.G. Bell's book, pipemax, general v-8 knowledge, and many production cars.
Sometimes a 1/2 length collector will work better, sometimes it won't. I would not try that first.
There are multiple "working theories" on how to tune headers, and they do not all agree, but in this case most of them agree 35 is a good bet, and I think it should work OK if the rest of the header is right or not.
Schools of thought which would support 35" collector:
The OLD short primary type tri-y header theories, A.G. Bell's book, pipemax, general v-8 knowledge, and many production cars.
Sometimes a 1/2 length collector will work better, sometimes it won't. I would not try that first.
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chimpvalet
- Pro
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- Joined: Wed Jun 04, 2014 2:02 am
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