Results 1 to 9 of 9

Some useful exhaust info

This is a discussion on Some useful exhaust info within the External Engine forums, part of the LSx Technical Help Section category; ...

  1. #1
    Member Ripper415's Avatar
    Join Date
    Sep 2005
    Location
    NY
    Age
    32
    Posts
    378

    Pewter
    2002 Camaro SS

    Some useful exhaust info

    I found this on another site and figured I'd post it here for everyone’s education...

    “Hey guys I just got done reading a good article in the May 2005 issue of Popular Hot Rodding Magazine. The article was written by David Vizard who seems to be one of the most accredited and respected people in the automotive performance world. In the article he stated that CFM is a great way to help develop a zero loss exhaust system. For zero loss a exhaust must flow 2.2 CFM per horsepower (This means less than 1% of total power produced by the engine is lost due to back pressure.). From reading the article I think that a lot of people that see gains when going from a 2.5” exhaust system to a 3” dual system see them because the muffler on the 2.5” system didn’t flow enough for their application. David stated that per square inch of exhaust tubing there is 115 CFM of flow. So plugging some numbers into the good ole TI-89….. ((3.14 * radius^2)*115[*2 for a dual exhaust system])/2.2 = Max hp supported with zero loss

    A 2.75” (stock) single system is good for a 310hp engine with zero loss…
    A 3” Single system is good for a 370hp engine with zero loss…
    A 3.5” Single system is good for a 503hp engine with zero loss…
    A 4” Single system is good for a 657hp engine with zero loss…
    A 2.25” dual system is good for a 457hp engine with zero loss…
    A 2.5” dual system is good for a 513hp engine with zero loss…
    A 3” dual system is good for a 812hp engine with zero loss…

    Now these numbers are assuming that everything else is set up perfectly. The muffler must flow as much as the open pipe or more to get zero loss at the listed hp levels. He also states that using a muffler with a larger inlet/outlet diameter than your exhaust pipe is a great way to get more out of a smaller diameter system since the muffler flow will be able to match the straight pipe flow. Now there are many other things to consider when designing an exhaust system but I figured this would give a great foundation to build on.”

  2. #2
    M6 King Hot Black Trans-Am's Avatar
    Join Date
    Mar 2006
    Location
    WI
    Posts
    5,085
    Blog Entries
    1

    09 EclipseGT 75 Chevy 4x4
    2001 Trans-Am 13 F-XT

    Good find!

  3. #3
    member since may 2000 nhraformula's Avatar
    Join Date
    Dec 2002
    Location
    n/w chicago
    Age
    48
    Posts
    6,933

    black
    2000 nhra edition formula

    that should be made a sticky.
    its been proven here before that just changing the muffler on stock systems will gain you about the same power as switching to a 3 inch catback. the muffler is the biggest restriction in our cars when stock.
    2000 nhra edition formula
    a few bolt ons, 379 rwhp
    11.96 @113.25

  4. #4
    Senior Member Hurley711's Avatar
    Join Date
    Jul 2005
    Location
    Earth
    Age
    41
    Posts
    3,362

    414 RWHP 395 RWTQ
    00 Black Ram Air Trans Am

    Soooo.....I am thinking about going with some duals through an X-pipe. I am running headers with an ORY, and a Volant CAI plus a TR224 cam. Should I be looking at the 2.25 duals, or should I get the 2.5 duals? In a year or so a LS6 manifold and heads will be going on, should I just get the 2.5?

  5. #5
    M6 King Hot Black Trans-Am's Avatar
    Join Date
    Mar 2006
    Location
    WI
    Posts
    5,085
    Blog Entries
    1

    09 EclipseGT 75 Chevy 4x4
    2001 Trans-Am 13 F-XT

    I'd say atleast 2.5 if your going to bother with doing true duals. That was always my rule of thumb.

  6. #6
    Pathelogical Liar BlackLT1Z28's Avatar
    Join Date
    Aug 2006
    Location
    Missouri
    Age
    30
    Posts
    1,476

    Black
    94 Camaro Z28

    That's pretty sweet. Good technical stuff.

  7. #7
    The Bandit Wesman's Avatar
    Join Date
    Apr 2006
    Location
    NJ
    Posts
    4,033

    SGM
    1998 Trans Am WS6

    Quote Originally Posted by Hot Black Trans-Am View Post
    I'd say atleast 2.5 if your going to bother with doing true duals. That was always my rule of thumb.
    Agreed. That way you always have room for more power should you decide you want to do more mods. 2.25" just seems like its too small, even with dual exhaust.

  8. #8
    Member Sam-SS's Avatar
    Join Date
    Feb 2006
    Location
    Treasure Island, FL
    Age
    79
    Posts
    109

    Red
    '99 Camaro SS

    Quote Originally Posted by Ripper415 View Post
    I found this on another site and figured I'd post it here for everyone’s education...
    Any chance that the other site had the full original article?
    I would like to read more on the subject. If so, could
    you post the URL to it?

    ...>>Sam

  9. #9
    Member Ripper415's Avatar
    Join Date
    Sep 2005
    Location
    NY
    Age
    32
    Posts
    378

    Pewter
    2002 Camaro SS

    this was all there was. i just copied and pasted it here.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. C5 SLP Loudmouth Exhaust - WTT for Stock C5 Z06 Ti Exhaust
    By EREBUS-SS in forum Parts Wanted / Trade
    Replies: 1
    Last Post: 09-27-2013, 01:08 PM
  2. C6 Z06 Exhaust Info?????
    By C6Z06PUNISHER in forum Corvette
    Replies: 16
    Last Post: 03-02-2010, 08:37 PM
  3. Question: I need some info
    By migueelw in forum Drag Racing
    Replies: 6
    Last Post: 09-26-2008, 10:09 AM
  4. Another exhaust thread: loud/deep exhaust?
    By Aetos in forum External Engine
    Replies: 37
    Last Post: 08-16-2008, 03:01 PM
  5. Anyone have any info? (Computer info)
    By blackSS01 in forum Almost Anything Goes
    Replies: 3
    Last Post: 02-01-2007, 02:44 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •