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Discussion Starter #1
is it bad to run open header like just thru the test pipe and thats it.
You make the most power and are the fastest running open header right?
i know you lose torque down low but when your racing your never at low rpms.
 

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It's possible to warp valves on some cars running open header because cold air gets drawn back into the motor through the header. The risk is low though, but there probably won't be much of a power gain on a relatively stock motor because aside from the cat, the exhaust isn't all that restrictive.
 

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was going to say that because it could cause the backfire making fugged up valves. just lazy.
 

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Don't do it, it will burn your exhaust valves. The thing that will make the most power would be to put a straight pipe from the header and paint it. Where the paint stops looking burnt after you run for a while that’s where you need to cut the pipe. It’s what we call scavenging, gives good hp and doesnt really hurt low end Torque.
 

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Discussion Starter #8
u dont need backpressure u want free flowing ya im aware of flowering warping the valves but thats if u do a down rev from high rpms, ill just drop the clutch so it wont down rev in gear

i dont see why u would burn exhuast valves

cuz what i want to do is run stock exhuast then a cut out before the high flow cat
so i look stock then i flip the switch and its free flowing and most hp while retaining stock look and sound while closed. most of the time it will be closed but sometimes ill race and want it open how bad do u think that is cuz i dont like exhuasts constant loudness is annoying
 

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Yea, dont worry about a cut out That will be ok, but believe me running open header all the time will burn your valves, the exhaust gasses come out hotter when allowed to flow free like that, esp. with a header like the rsx comes with. A cut out will work but it will confuse your computer and you'll get a CEL and then lose HP from open loop operation, the only way to really make HP from a cutout would be to upgrade your computer as well, and I'm talking about one of those programable ones.
 

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Discussion Starter #10
hmm why would it confuse my ecu? it shouldnt throw a cat ineffusceny(sp?) code cuz i have capsers o2 sim so i think my ecu will be fine, not talking from experince tho but i just dont see why my ecu would fuck up
 

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I ran my header open from my house for a block to the muffler shop to have the cat welded in. Not only did my car sound like a broken harley (it was LOUD!!!!); it seemed to have NO torque down low. I only reved to about 4K the whole time, but it wont' be something I'd do on purpose.
 

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I do it and im running great. I wouldnt do it 24/7 though, just for track and dyno time. I wouldnt say its 100% safe, but I wouldnt worry about it. As long as you have the exhaust gasses exiting pretty far from the engine.
 

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clutch burner
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i ran open header just around town for a few minutes because i was waiting for my test pipe to come UPS and i had nothing better todo till the truck came....and it def lost alot of low end and high end was loud but definitley slower...

and vroom running open header DOES make you lose power and is not good for the engine..RIGHT lol

i was referring to running open header before.....open test pipe im not sure it may still be too short to make enough backpressure? :dontknow:
 

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Ninety3octane said:
i ran open header just around town for a few minutes because i was waiting for my test pipe to come UPS and i had nothing better todo till the truck came....and it def lost alot of low end and high end was loud but definitley slower...

and vroom running open header DOES make you lose power and is not good for the engine..RIGHT lol

i was referring to running open header before.....open test pipe im not sure it may still be too short to make enough backpressure? :dontknow:

all depending on whats done to your car, because i had an integra and when i had the exhaust on it cut the power to 150 at the wheels, when we dropped the exhaust at the header i made 186 at the wheels. i had to get exhaust with larger piping so i could push the air out that i was bringing in. now as far as if it's good for your car or not i have no say because i honestly don't know.
 

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Discussion Starter #18
u do make power but lose torque thats why u think u lost power when driving u really didnt its just all high end hp, if u think u lose hp then your just plan dumb. u want the exhuast free flowing so basically srtait out is the best u can do. i deff need to let all the exhuast out im taking in more air then i can squeeze out hence the cut out will make my car a top end vtec monster compared to one with an exhuast that does what the stock exhuat does flow thru it with bends and muffling.

warning if the header is too short in which case my setup isnt.
1. warped valves they will flower like a tulup
2. burn exhuast valves
now this only happens in very cold weather and if u down rev so the engine sux cold air back in.
of course im not gunna daily drive with the cut out open to strait pipe from header so everything should be ok

just cuz u dont feel a diff or it feels slower doesnt mean it is, hondata for example alot of people said they dont feel it cuz the power band is so smooth which is better for acceleration
 

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clutch burner
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vrooom said:
all depending on whats done to your car, because i had an integra and when i had the exhaust on it cut the power to 150 at the wheels, when we dropped the exhaust at the header i made 186 at the wheels. i had to get exhaust with larger piping so i could push the air out that i was bringing in. now as far as if it's good for your car or not i have no say because i honestly don't know.
but an integra header has much much longer runners from the head to where the exhaust bolts to...

when you do run open header theres nowhere to plug the o2 sensors into which makes the car run like shit and makes it slower most of the time.
 
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