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Backpressure and cutout "theory"

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Old 06-29-2006, 09:31 AM
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Default Backpressure and cutout "theory"

Ok, I've been pondering this "theory" for a while. Looking for some input or if anyone has tried it yet.

My idea stemmed from seeing many different timeslips and the effects of cut-outs on 60' and 1/4 times. From what I've seen is the average gain is a 1/10 in the overall time and 1 more mph with cutouts open, but the 60' time suffers vs full exhaust times.

Now my idea is; if you have E-cutouts you could benefit from both scenarios right?? Have them closed for staging and launch through first gear and hit the switch in the beginning or middle of second gear. This would give the needed backpressure for low end torque off the launch and give the open header flow for the topend. If that would work it could turn the 1/10 gain into a 3/10 gain maybe 4 as well as the added mph.

I will test this soon, but as of now I have no trans in the truck and my exhaust is not yet complete. So your thoughts, experiences, and comments/opinions are requested.
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Old 06-29-2006, 11:02 AM
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Interesting theory that does seem logical. I'm curious as to what the results will be...
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Old 06-29-2006, 11:44 AM
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I would think by the time the cut out got all the way open, you would be done with the 1/4
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Old 06-29-2006, 11:50 AM
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I'll say the same thing on the intake side of things. I cut the 'baffles' off the intake tube and noticed a drop in performance on the low end. I wasn't happy with it at all so I bought a new factory intake.

I run my exhaust open all the time... until I see the police. I definately feel sluggish off the line, which is embarrasing given the amount of noise I'm making. Mid-range is great though. But with the gas savings I'm getting..., I just keep it open.
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Old 06-29-2006, 12:31 PM
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Originally Posted by white1
I would think by the time the cut out got all the way open, you would be done with the 1/4
they open rather quickly maybe 2-3 seconds. this should be intresting
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Old 06-29-2006, 12:44 PM
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Originally Posted by blu01slver
they open rather quickly maybe 2-3 seconds. this should be intresting
, there should be ample time down the track to see a benefit
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Old 06-29-2006, 12:53 PM
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with the mods you'll be running, i think you benefit more from the cutout open rather than closed.
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Old 06-29-2006, 12:58 PM
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Interesting, I was thinking the same thing, get and e cutout, keep it closed till your past your 60' then open em up, get the benifits of both.

I've got a e cutout sitting here, I just need to get a splitter pipe installed so I can hook it up.
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Old 06-29-2006, 01:00 PM
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Originally Posted by bluecajun5.3
with the mods you'll be running, i think you benefit more from the cutout open rather than closed.
I agree, but, in general I still think it'd be most beneficial to keep as much low end torque as we can to get our heavier trucks to launch the best we can.
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Old 06-29-2006, 01:03 PM
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there's only one way to see.
try them both!
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