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Exhaust back pressure, myth or fact? 

 

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 Post subject: Exhaust back pressure, myth or fact?
Posted: Wed Aug 03, 2011 8:18 pm 
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I'm getting differing opinions on required back pressure on the exhaust.

Get the camps that say get the gases out fast as possible with no restrictions, then those they say you require some back pressure.

What are the facts?

I have blown out my cat and removed the rear muffler from the BA XR6, sound is almost perfect as *I* want it. The extractors will finish off the note I'm chasing.

Will lack of back pressure be an issue?

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Wed Aug 03, 2011 8:21 pm 
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Myth. If you want to know why do a search, has been covered many times (even brought up in a current thread in this section.

Close f**k thread.

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Wed Aug 03, 2011 8:24 pm 
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Because I'm nice - in the following thread there are several good posts explaining why you should never use the words back pressure at about page 2...it had someone trying to argue that you can't design extractors to give low down torque.

http://www.fordmods.com/ford-4l-and-6-cylinder-f1/best-extractors-for-low-down-power-torque-for-el-t73445.html

 

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EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Wed Aug 03, 2011 10:25 pm 
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no one will ever convince that an exhaust system that pushes exhaust gases BACK INTO the combustion chamber is a good idea.

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Wed Aug 03, 2011 11:26 pm 
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Back pressure is not the aim, it is a by-product of trying to maintain some velocity in the pipes, but there are many factors in exhaust tuning not just velocity.

Check here for all your backpressure needs and much much more.
http://kalecoauto.com/index.php?main_pa ... ducts_id=3

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Thu Aug 04, 2011 7:52 am 
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skidder wrote:
Because I'm nice - in the following thread there are several good posts explaining why you should never use the words back pressure at about page 2...it had someone trying to argue that you can't design extractors to give low down torque.

http://www.fordmods.com/ford-4l-and-6-cylinder-f1/best-extractors-for-low-down-power-torque-for-el-t73445.html

Thanks for the rant but I've already looked in that thread and many others. The information is quite conflicting and I'm more after an answer if people would believe that once I chuck some extractors on if I will have an issue with my set up.

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Thu Aug 04, 2011 12:12 pm 
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Deff wrote:
skidder wrote:
Because I'm nice - in the following thread there are several good posts explaining why you should never use the words back pressure at about page 2...it had someone trying to argue that you can't design extractors to give low down torque.

http://www.fordmods.com/ford-4l-and-6-cylinder-f1/best-extractors-for-low-down-power-torque-for-el-t73445.html

Thanks for the rant but I've already looked in that thread and many others. The information is quite conflicting and I'm more after an answer if people would believe that once I chuck some extractors on if I will have an issue with my set up.


Deff wrote:
\

What are the facts?

I have blown out my cat and removed the rear muffler from the BA XR6, sound is almost perfect as *I* want it. The extractors will finish off the note I'm chasing.

Will lack of back pressure be an issue?



With what you have now, I will garrenty to you do indeed have back pressure.

 

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 Post subject: Re: Exhaust back pressure, myth or fact?
Posted: Thu Aug 04, 2011 2:46 pm 
Getting Side Ways
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Deff wrote:
skidder wrote:
Because I'm nice - in the following thread there are several good posts explaining why you should never use the words back pressure at about page 2...it had someone trying to argue that you can't design extractors to give low down torque.

http://www.fordmods.com/ford-4l-and-6-cylinder-f1/best-extractors-for-low-down-power-torque-for-el-t73445.html

Thanks for the rant but I've already looked in that thread and many others. The information is quite conflicting and I'm more after an answer if people would believe that once I chuck some extractors on if I will have an issue with my set up.


Lack of 'back pressure' won't be a problem. If you select headers not designed to make power wherever you want it obviously that will be a problem, but this will be due to lack of efficiency at desired rpm.

I'm sorry I wasn't clear enough earlier....the above thread gives a good idea of how exhaust systems work...to make your way through it IGNORE any post that uses 'back pressure' as a justification....or just any post by green car in general.

 

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EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

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