backpressure
Senior User
Joined: Jul 2003
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From: irwin,pa
interesting
Originally Posted by Saurian
Some backpressure is good, though.
Look at the new 6.0's. Alot of people that are blowing out there Turbo's..what do they have in common? Free-flowing 4 inch exhaust that isn't providing enough backpressure..so their turbo overboosts and blows itself up.
When people say that some backpressure is good, they mean that the exhaust gas velocity. It's nice to correct them, but not to an overextent.
You need to match pipe diameter to horsepower - or the level that you want to get to.
Don't dragsters run a pipe out from each individual cylinder? I thought they had pipes off of each cylinder going down...which is why they have trouble blowing out their spark over the nice 6 second runs.
Look at the new 6.0's. Alot of people that are blowing out there Turbo's..what do they have in common? Free-flowing 4 inch exhaust that isn't providing enough backpressure..so their turbo overboosts and blows itself up.
When people say that some backpressure is good, they mean that the exhaust gas velocity. It's nice to correct them, but not to an overextent.
You need to match pipe diameter to horsepower - or the level that you want to get to.
Don't dragsters run a pipe out from each individual cylinder? I thought they had pipes off of each cylinder going down...which is why they have trouble blowing out their spark over the nice 6 second runs.
2- faster spool up time- boost is not based on the exhaust size- i went to 4" on my 1989 pontiac turbo trans am- -when i was running the stock te 28 turbo-spool up time was considerably less- i showed this topic to the grand national guys and they got a kick out of this- my.02$
New User
Joined: May 2004
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Thanks Sigma, sounds like you know what your talking about. What would be the good pipe size to run on 2000- f150,5.4, I drive around town and haul stuff time to time. I want more low end. What pipe size would you suggest, thanks.
Senior User
Joined: Jul 2003
Posts: 379
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From: irwin,pa
size
2 1/2" mandrell bent with a straight through type muffler,ie. magnaflow- will keep the tq up-- maybe reason ford went with 2 1/2" in the first place?i went with a 3" #15609 ss magnaflow catback and i can honestly say i didn't lose tq- maybe picked up a few lbs- but hp definetly improved-shoot me email- got an interesting dyno of a 5.4 with my exhaust -phil
New User
Joined: May 2004
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Openclasspro
OPENCLASSPRO,
I don't have e-mail privelges yet on the site. Thanks for the info though. I know I'll probably catch some 'hell' over this question, but what about gutting the cats on my truck 2000f-150, and doing some kindof exhaut work on my truck. I'm running a Borla dual exhaust muffler on there now. Do you think I would get more sound that away. Thanks for the help.
I don't have e-mail privelges yet on the site. Thanks for the info though. I know I'll probably catch some 'hell' over this question, but what about gutting the cats on my truck 2000f-150, and doing some kindof exhaut work on my truck. I'm running a Borla dual exhaust muffler on there now. Do you think I would get more sound that away. Thanks for the help.
Posting Guru
Joined: Feb 2002
Posts: 2,404
Likes: 3
From: Cleveland, WI USA
Sigma,
That's the best and most accurate description of backpressure I've read yet. I'm gonna e-mail a link to this thread to about 20 people I know that swear backpressure is something you try to achieve as opposed to a by-product.
Quoting another thread "if you think back pressure is good, shove a potato in your exhaust and see how good it runs".
I love that!
Kevin K.
That's the best and most accurate description of backpressure I've read yet. I'm gonna e-mail a link to this thread to about 20 people I know that swear backpressure is something you try to achieve as opposed to a by-product.
Quoting another thread "if you think back pressure is good, shove a potato in your exhaust and see how good it runs".
I love that!
Kevin K.