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Cutout Backpressure question

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Old 04-22-2006, 12:26 AM
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Question Cutout Backpressure question

Are there any problems with running a cutout wide open? I heard from a buddy of mine that if you have a cutout open for a long period of time, it can cause problems. he said that an open cutout is the same as open headers. He also said that the lack of backpressure from the open cutout, can cause your valves and seals to burn up quicker. does anyone have any evidence of this? or is he full of it. Thanks for any input.
Old 04-22-2006, 12:42 AM
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i've never had any problems and my car drives faster and smoother with them open. open headers are a little different because the O2's are so clese to the outside air (only a few inches). i've ran both. my car would hardley idle with open headers, but once i but my Y-pipe back on with dual cut out's the car idled fine. the cutouts are on'y abpbut 12 inches from the headers but it makes a difference
Old 04-22-2006, 12:57 AM
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I have an electirc cutout now and I have it open most of the time. I've only had it about a month but i have noticed any problems either. I'm just wondering about long term.
Old 04-22-2006, 01:22 AM
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mines been open for about 2 years, no probs!
Old 04-24-2006, 09:46 AM
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had mine for 2 years no problem but they are coming off this week just got corsa catback
Old 04-24-2006, 09:52 AM
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Originally Posted by 99_hugger_Z
Are there any problems with running a cutout wide open? I heard from a buddy of mine that if you have a cutout open for a long period of time, it can cause problems. he said that an open cutout is the same as open headers. He also said that the lack of backpressure from the open cutout, can cause your valves and seals to burn up quicker. does anyone have any evidence of this? or is he full of it. Thanks for any input.
Basically your buddy is so full of it, it must be coming out of his ears

Have a read of the sticky in this forum (exhaust/induction) and learn what back pressure is and what it does and doesn't do.

**It's one of the great 20th Centuary miths **
Old 04-24-2006, 12:54 PM
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If backpressure creates power, then stick a banana in your exhaust and go pull some tree stumps. Proper Sonic tuning is what scavenges the exhaust gases from the cylinder and creates power. As far as burning up valves, I've personally never seen anyone have a problem with that (doesn't say a whole lot). I've seen videos of engines running without any exhaust manifold(s) at all. A Cutout probably won't net you better gains than a properly tuned exhaust, but from what I can tell anything seems to be better than the stock configuration.
Old 04-24-2006, 04:04 PM
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Thanks for all the input. My buddy is just jealous because I own him at the track. He has a 02 mustang GT He said he heard about that on one of his forums.
Old 04-24-2006, 04:31 PM
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maybe it has something to do with his being a 4.6 and ours a 5.7.. is there a certain cu. where a cutout loses power? has to be
Old 04-24-2006, 04:44 PM
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Originally Posted by 99_hugger_Z
He also said that the lack of backpressure from the open cutout, can cause your valves and seals to burn up quicker.

Its a fact from back in the day when valve seats were not hardened. In the 60's you needed back pressure, and High octane fuel or the valves were not happy. Alot of people think the same is true about todays engines.
Old 04-25-2006, 05:50 AM
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Originally Posted by carado1984
maybe it has something to do with his being a 4.6 and ours a 5.7.. is there a certain cu. where a cutout loses power? has to be
eh - I sure hope this is a joke, as you seriuosly can't believe what you have written.
Old 04-25-2006, 05:54 AM
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Originally Posted by OBO
Its a fact from back in the day when valve seats were not hardened. In the 60's you needed back pressure, and High octane fuel or the valves were not happy. Alot of people think the same is true about todays engines.
another "eh"

The valve seats are fine, aircraft engines don't run an exhaust except of some angled tubing - this has always been this way yet they don't have issues with the valve seats.

The only time backpressure is an issue is for proper tuning. If you remove the restriction and reduce back pressure and FAIL to retune for the new a/f mixture then problems can occur, however this is NOT a result of backpressure but the lack of ability to set the engine up.



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