Cutout flow disturbance?
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On The Tree
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From: Albuquerque
Cutout flow disturbance? We spend extra $$ for smooth, mandrell bent exhaust system components. Has anyone seen any data on the affect of the turbulence/affect on flow caused by the presence of cutouts (when they are capped)? 
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From: new england
Re: Cutout flow disturbance? This is a good question, i havent done testing but most electric cutouts appear to restrictive to flow when butterfly is open because its too small and not conducive to flow. As for flow when closed i say it would act like a accumulator or resovoir pocket and probably doesnt affect or hurt flow at all.
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From: Chicago
Re: Cutout flow disturbance? I'm not 100% sure but I think there was a post on this quite a while back. From what I remember it was concluded that the cutout basically acts as an accumulator when closed (ie what LS1derfull stated) and only has a minimal affect on flow when open. Something like a ~1-2 horsepower difference at best because of the high velocity of the air as it's exiting.
I could be wrong though, this is just from memory...
I could be wrong though, this is just from memory...
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From: Chicago
Re: Cutout flow disturbance? Forgot to add...I think the issue of a flow restriction elsewhere in the exhaust is more of an issue because there's more of an overall impact. Aka, if there's a bad bend real early it negatively impacts flow for the entire rest of the exhaust gas' path of travel, whereas with a cutout the gas is basically at the end of it's path. Just a theory 
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On The Tree
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From: Albuquerque
Re: Cutout flow disturbance? Thanks for the info, but I don't understand the affect of an "accumulator" in the exhaust line.
I'm wondering if I'll be paying a flow penalty for the 90% of the time when the cutouts are capped.
I'm wondering if I'll be paying a flow penalty for the 90% of the time when the cutouts are capped.
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From: Troy, AL
Re: Cutout flow disturbance? "I'm wondering if I'll be paying a flow penalty for the 90% of the time when the cutouts are capped."
No. If there is a penalty, it would be so small that you couldn't prove it on a dyno. That extra path is filled and therefore plugged with air. Think about it. The air in that part will actually act as a wall to guide the moving air on by. That's what was meant by an accumulator.
And yes, the farther away from the engine a restriction is, the less effect it has. Why? Because the exhaust cools and shrinks as it moves away from the engine.
No. If there is a penalty, it would be so small that you couldn't prove it on a dyno. That extra path is filled and therefore plugged with air. Think about it. The air in that part will actually act as a wall to guide the moving air on by. That's what was meant by an accumulator.
And yes, the farther away from the engine a restriction is, the less effect it has. Why? Because the exhaust cools and shrinks as it moves away from the engine.
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From: Chicago
Re: Cutout flow disturbance? Colonel pretty much took the words out of my mouth 
. Basically, the hanging piece of the cutout would "fill up" with air and exhaust gas, thus putting the remaining gases back on a linear path.
edit: bottom line you'll gain a lot more than you'll lose with the cutout so I wouldn't
too much over it 
.
. Basically, the hanging piece of the cutout would "fill up" with air and exhaust gas, thus putting the remaining gases back on a linear path. edit: bottom line you'll gain a lot more than you'll lose with the cutout so I wouldn't
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