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Registered:
August 2004
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Re: 1G query...
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Sun, 16 January 2005 01:15
 
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As far as I know, all turbo engines had them, not sure on the NA ones, and supercharged doesn't have them as the intake manifold is different. The problem with them is that the rod that does through the middle goes through every runner except the very front and rear runner, so there are 12 runners, 2 for each cylinder, and the butterflies cover one runner in each of the 2 per cylinder, but due to the design, the rod that passes through the middle, only goes through ports number 2 through 11, and there is nothing at all in 1 and 12, as even in every other port that desn't have a butterfly in it, the rod still has to pass through it to get to the one next to it.
Now, hopefully that wasn't all too confusing, but if you get the gist, the problem is, that that little piece or rod reduces flow by 11cfm, so the manifold flows 11cfm more on cylinders and and 6, not good, as these are 2 cylinders that generally are the first to go when you start melting pistons and stuff. The added problem with this is that the manifold with no butterflies attached already flows 10cfm more air on 1 and 6 on its own, so add the extra 11 cfm, and you have a pretty huge 21cfm more air on cylinder 1 and 6 than every other cylinder.
The manifold flows around 280cfm standard, so thats around 8% or something. Its no big deal in a mild engine, but not good if you are pushing it pretty hard with cooler, turbo and boost, the simple fix is drill and tap a 4mm hole in the ends and install a bolt that just screws straight in, making it the same as every other port, then you only have 10cfm difference to deal with, or 3-4%. They will make vertually no difference to power and should give a reasonable gain down low, so ZI would leave them there.
Cheers..................6BOOST:)
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| | Subject | Poster | Date |
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1G query...
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alterd | Fri, 14 January 2005 23:13 |
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Re: 1G query...
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chrisellis | Fri, 14 January 2005 23:35 |
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Re: 1G query...
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thechuckster | Sat, 15 January 2005 00:34 |
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Re: 1G query...
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Ribbo | Sat, 15 January 2005 02:32 |
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Re: 1G query...
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M.W.P. | Sat, 15 January 2005 11:30 |
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Re: 1G query...
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HyDrA | Sat, 15 January 2005 23:39 |
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Re: 1G query...
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680OST | Sun, 16 January 2005 01:15 |
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Re: 1G query...
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ddeane | Sun, 16 January 2005 03:01 |
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Re: 1G query...
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alterd | Sun, 16 January 2005 18:51 |
