 Back Pressure in NA, Is it really needed? |
 Apr 18, 2004 - 8:11 PM
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 Enthusiast  Joined May 24, '03 From Milton, Delaware Currently Offline Reputation: 0 (0%)  |
Ok, i know everyone says that Back Pressure is needed in NA engines but i need to know whether this is true.
Article If back pressure is actually REQUIRED, then why do you see dragsters w/ nothing but straight pipes coming directly off the engine? Isnt it more likely that a car simply loses power because its not tuned correctly? Granted there is going to be some back pressure caused by expanding gasses in teh dragsters exhaust, but minimal say compared to mufflers and such. I have read in several places that new cams and such will solve problems associated w/ loss of backpressure, and basically cars just arent stock set up to run w/ much less back pressure. So say you're allowed to do anything you want to an engine, besides overbore w/e, or FI, is almost no backpressure really bad? Say you had an exhaust like this.... CLICK but minus the turbo of the wrx? IONO maybe i'm rambling cuz i was just arguing w/ my friend about this.... -Ryan -------------------- AIM : FAQdaWorld
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Apr 19, 2004 - 7:04 PM
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 Enthusiast Joined Aug 29, '02 From Dallas, Tx Currently Offline Reputation: 0 (0%) |
No no no no no.
Exactly right. This guy knows his stuff. There is NOTHING NOTHING NOTHING good about back pressure unless you have cams that have a rediculous amount of overlap (we don't; think early '70s muscle cars). To make a really long fluid dynamics discussion really short: Backpressure (resistance to flow) = Bad (always) Exhaust gas velocity = must be in useful range (i.e. pipe not too small, not too big)(generally around 2.25"-2.75" post collector tube diameter for a 1.8l 4cyl) Turbo cars are less picky about velocity, you can run a rediculously large exhaust (to aid quick spooling) and not really suffer any ill consequences. |
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Posts in this topic
FAQdaWorld Back Pressure in NA Apr 18, 2004 - 8:11 PM
mikew04 backpressure is bad in any car. what you want is y... Apr 18, 2004 - 9:04 PM 1bwilson Back pressure is fine in a n/a car. Its not going... Apr 19, 2004 - 12:54 PM subsolo_21 *Back pressure in boosted car = slower spooling. Apr 19, 2004 - 1:00 PM FAQdaWorld right, i understand this w/ the backpressure in tu... Apr 19, 2004 - 2:22 PM FAQdaWorld Ok spedtoe, u seem to know ur stuff.Let me phrase ... Apr 20, 2004 - 10:52 AM 1bwilson You mean you want it to fire straight out of the h... Apr 20, 2004 - 12:51 PM FAQdaWorld No, i dont want to. I'm just saying for argume... Apr 20, 2004 - 1:11 PM SpedToe169 It would run like crap because it has no exhaust g... Apr 20, 2004 - 5:39 PM FAQdaWorld spedtoe == l337, j/k mang, u rock. Thanks for the ... Apr 20, 2004 - 10:09 PM
SpedToe169 Anytime! I've actually been having this d... Apr 21, 2004 - 9:09 AM |
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