How a properly built exhaust system works

  1. Welcome to Toyota Tundra Forums : Tundra Solutions Forums General discussion forum for Toyota Trucks

    Welcome to Toyota Tundra Forums : Tundra Solutions Forums - a website dedicated to all things Toyota Tundra.

    You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, Join Toyota Tundra Forums : Tundra Solutions Forums today!
     
+ Reply to Thread
Page 1 of 31 12345611 ... LastLast
Results 1 to 15 of 461
Like Tree129Likes

Thread: How a properly built exhaust system works

  1. #1
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758

    Default How a properly built exhaust system works

    I have done a ton of research on this subject and thought it would be helpful to a lot of member's here if I shared some general knowledge.

    There are 3 general ways to quiet down an exhaust system on a vehicle. Restriction, Reflection, and Absorption. Guess what OEM uses. Unless it's an exotic car it's likely restriction. Reflection is what some aftermarket companies use but on the top end of the RPM range they will actually restrict flow as much or more than stock. Absorption is what exotic car manufacturers and high end muffler manufacturers use. On a medium level production line the reflection style muffler is the cheapest to manufacture.

    Let's touch on the subjects of restriction and backpressure. Most engines need some backpressure in order to scavenge properly. Backpressure and scavenging are 2 different things yet they work together. Everybody has a friend who has violently shouted, "you need some backpressure to make power!" But has anybody ever thought about why you need that backpressure? Without backpressure you wouldn't have scavenging. Scavenging is what makes power, not backpressure. That's why you lose power by putting on a huge cat back but leaving your stock manifolds and y pipe.

    Take my truck for example, how can I get away with true dual 2.5" tubing with flow through mufflers? The backpressure and scavenging has been greatly improved by adding Long Tube Headers. All the backpressure this engine needs is in the headers since the exhaust is able to scavenge so efficiently. In other words at peak volumetric efficiency the headers actually 'siphon' the exhaust out of the head. Unlike stock manifolds which have much less scavenging, the exhaust needs to be pushed out of the head into a high backpressure low flowing manifold.

    The next most restrictive area the exhaust needs to overcome in a stock exhaust system is the 'y' pipe. Whether crimped to nothing like stock, or crafted together professionally by an exhaust shop the 'y' pipe is VERY restrictive. Then hit the cats, the resonator, the muffler, and finally the huge crimp bend to go up and over the rear end. Each of these things by themselves are very restrictive not to mention when you put them together on an entire system.

    Exhaust flows exactly like traffic on a freeway! Put 4 on ramps like 20 feet away from each other with no runway and expect the merging cars not to slow down traffic(manifold). Then line the lanes with 6 foot high poles just far apart enough to squeeze your vehicle through.(cats) Now merge 8 lanes into 4. (y pipe) Then make 20 off ramps on each side of the freeway and no runway's.(resonators) Put a maze of different roads going all different directions but ending up in the same location to exit the maze.(muffler) Finally put a huge curve with 2 less lanes.(up and over the axle.)

    If properly built the exhaust would flow like 4 long sweeping on ramps, (headers) Each bank would never merge but instead flow out of the tailpipe using long sweeping curves that never lose a lane.

    The above analogies are EXACTLY how exhaust flows. For all you hydraulics experts out there, you can also picture the exhaust as water traveling through pipes. The OEM didn't design the manifolds to lose power, they didn't design the crimped 'y' pipe to lose power, nor the resonator, muffler, tailpipe. They designed them to make the system quiet and lose the least amount of power possible while targeting a specific decibel at a target price on a large scale production level! So in other words, cheap, quiet, fast. I was always curious as to how much was lost so I built my own system using S&S Longtubes, 32 horsepower to the wheels! Mileage has also increased as long as I don't drive like a jack-***.

    Since most aren't going to spend the money on a full race exhaust system, I'll stay focused on the 2 systems that would make the most power on these trucks. I have tried almost every configuration possible with dyno testing on some of them. I will write part 2 of this when I have time.
    Last edited by escondidotundra; 04-19-2010 at 11:49 PM.

  2. Remove Advertisements
    Toyota Tundra Forum
    Advertisements
     

  3. #2
    September Sky Highwaylizard's Avatar
    Join Date
    Sep 2008
    Location
    above the below
    Posts
    7,217
    Liked
    2208 times
    Images
    65
    Rep Power
    229686

    Default Re: How a properly built exhaust system works

    Very informative. Please post up more on this a I am just beginning my research into this area.
    https://www.facebook.com/septemberskyrocks
    276,558 miles on the odometer [come see me when you get that on your ford]



    2004 Tundra Double Cab Limited Edition 4.7 liter V8, four speed automatic, four wheel drive, testing platform for fuel economy, self designed cold air intake using ram air principle, Ultragauge, Fitch Fuel Catalyst, Aero Turbine, "Foolie Exhaust" from Aero Turbine back, AFe open intake, Mobile 1 in the engine, NAPA oil filter, NAPA in the differentials. 3:91 gears in the front (Thanks Cajuntundra!) and rear (Thanks Nytrousboy!) differentials, Michelin LTX M/S2 tires

  4. #3
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    Quote Originally Posted by Highwaylizard View Post
    Very informative. Please post up more on this a I am just beginning my research into this area.
    Hey, I just edited the article, I fell asleep last night punching the keyboard I woke up in the middle of the night and pushed submit.

    I'll write part 2 tonight.

  5. #4
    September Sky Highwaylizard's Avatar
    Join Date
    Sep 2008
    Location
    above the below
    Posts
    7,217
    Liked
    2208 times
    Images
    65
    Rep Power
    229686

    Default Re: How a properly built exhaust system works

    BUMP BUMP - More articles? please?
    https://www.facebook.com/septemberskyrocks
    276,558 miles on the odometer [come see me when you get that on your ford]



    2004 Tundra Double Cab Limited Edition 4.7 liter V8, four speed automatic, four wheel drive, testing platform for fuel economy, self designed cold air intake using ram air principle, Ultragauge, Fitch Fuel Catalyst, Aero Turbine, "Foolie Exhaust" from Aero Turbine back, AFe open intake, Mobile 1 in the engine, NAPA oil filter, NAPA in the differentials. 3:91 gears in the front (Thanks Cajuntundra!) and rear (Thanks Nytrousboy!) differentials, Michelin LTX M/S2 tires

  6. #5
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    Quote Originally Posted by Highwaylizard View Post
    BUMP BUMP - More articles? please?
    Thanks for the reminder!

    Most Tundra owners aren't going to go 'full race,, meaning no cats'. To me it's still up in the air as to whether it's even beneficial. I've read lots of fact and opinion on the subject. I have recently built a new 'h' pipe for my 'full race' system. This pipe removes the cats. I can tell you this, when I went from single to dual, with cats, there was a REAL noticeable difference! The truck came alive. Going cat free, can't say I notice much. I am in the process of experimenting with new mufflers since my current design is waaaay too loud with tri y long tubes and no cats. Once I've made the mufflers I'm gonna stick with, I'll put it back on the dyno. In the mean time back to the subject.

    Once again most people won't go full race, it's too expensive. From what I've seen there are 2 types of guys. Both want more sound and power. One is willing to spend some money and the other either can't or isn't willing. The guy willing to spend the money will usually buy a cat back, and the guy with not so much money is gonna just buy a muffler. The guy with the money doesn't want it too loud, but the guy without the money wants it loud.

    I understand both guys since I've been both guys at some time in my life. I am kinda in between right now, I want it loud, but not open pipes loud. But back on subject! Both scenarios above can be done a right way and both can be done a wrong way.

    I'll start with the cheaper way. (and there's nothing wrong with this way if done correctly) To simply cut out the stock muffler and replace with a louder one. I won't mention any names, that's not the point of this article, but I've seen this all too often! Guys cut out the stocker put on a 'v' style baffled muffler and let it dump under the truck! HUH! First off you need some tubing after the muffler, second, to put a big wall and a bunch of baffles right in the way of the exhaust flow, and third, to let the muffler resonate under your truck like that! WTF? Not to mention, you're breathing all that toxic exhaust at every stop light. Then we need to consider the flow capabilities of the muffler. The specific muffler that I am talking about was originally designed to make a V8 muscle car sound cool and flow 4 cylinders through it, not all eight!

    When you put this muffler 'in the way' the back pressure increases as the rpm increases. This is the opposite of what you want. So now you ask yourself, what's the alternative? A flow through style muffler! Some guys call it a glasspack, but rest assured, a glasspack isn't what you want. Glasspack is louvered and mild steel core, outer case is too small, and they neck down to 1 7/8" on a 2 1/2" muffler. No good. You want a muffler with a Stainless Steel Perforated core with a properly sized canister and true sizing in and out. Your high end sports cars use this type of muffler why not you? If you insist on dumping this under the truck go ahead, but let me assure you, it's well worth the money/effort to run a tailpipe to the side just before the rear tire. Cut up the old tailpipe and re-weld it to exit the vehicle, don't breath that poison! You will gain at least 5HP with this set up, not lose it. You will also gain a pretty substantial throttle response and mpg.

    For the guys who want it quiet and aren't afraid to spend a little money, I've got news for you,in most cases there's no need for a catback! Most lose power! Most have much larger tubing and that causes the velocity to slow creating backpressure. Unless you replace the manifolds and open up the restrictive y pipe and all the tubing from the headers to the single tailpipe you're wasting your money. If it's just about the growl and a little power/throttle response, cut out the stock muff and weld in the above flow through. It will be much quieter with the tailpipe and you will gain power!

    The above scenarios are based on the 1st gen 4.7 Liters. I will continue this article in the next few weeks after I do a true dual 'h' pipe 5.7L with 2.25" tubing. I will try and include before and after dyno proof and lots of sound clips and pics. Will probably start a new thread and put a link here. Stay tuned!
    Last edited by escondidotundra; 05-12-2010 at 11:56 PM.

  7. #6
    Rookie stkaelk's Avatar
    Join Date
    Sep 2009
    Location
    Missoula. MT
    Age
    49
    Posts
    6
    Liked
    0 times
    Images
    5
    Rep Power
    0

    Default Re: How a properly built exhaust system works

    Looking forward to that next post. I've been itching for a better exhaust. I'll wait for more info so I can do it right.

    '08 5.7 Dbl Cab, Bilstein 5100 3" lift front, 5100 rear, Toytech 1" block rear, Toytech 1" diff. drop, Daytime running lights disabled!

  8. #7
    Veteran Member cheapskate's Avatar
    Join Date
    Feb 2009
    Location
    Kitchener Ontario
    Posts
    1,993
    Liked
    407 times
    Images
    15
    Rep Power
    30268

    Default Re: How a properly built exhaust system works

    Interesting reading. Can anyone tell me how I can bookmark a thread like this in the future without having to post a comment? Do I use the permalink tab or "subscribe" tab?
    2012 Crewmax TRD 5.7, 4x4, 15% tint all around plus sunstrip. Ionic Gladiator running boards. Weathertechs front and rear. Line X, AVS vent visors. Viper 5301 2 way remote start, MBRP S5316304 cat back exhaust. Bakflip Fibermax tonneau cover.
    Traded in my 05 4x4 DC, AFE CAI, Magnaflow Catback15820, Line X bedliner.

  9. #8
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    Quote Originally Posted by cheapskate View Post
    Interesting reading. Can anyone tell me how I can bookmark a thread like this in the future without having to post a comment? Do I use the permalink tab or "subscribe" tab?
    Top right...click on thread tools.... In your usercp you can turn on or off automatic subscriptions

  10. #9
    Senior Contributor tundrunk's Avatar
    Join Date
    Nov 2009
    Location
    check the bar or liquor store
    Posts
    6,164
    Liked
    2482 times
    Images
    216
    Rep Power
    248772

    Default Re: How a properly built exhaust system works

    I agree with everything you said, good job.
    Glad somebody is using logic rather than making assumptions, can't tell you how many times I've heard people say go with a bigger tailpipe, it opens up for more HP!
    youvebeenkumped likes this.
    "Drunk by noon but that's okay, I'll be President some day"
    - Sublime

  11. #10
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    Quote Originally Posted by tundrunk View Post
    I agree with everything you said, good job.
    Glad somebody is using logic rather than making assumptions, can't tell you how many times I've heard people say go with a bigger tailpipe, it opens up for more HP!
    hahahahahaha, bigger pipes actually make MORE backpressure! The velocity of the exhaust slows and actually goes stagnant, the exhaust trying to exit the system hits this stagnant exhaust and it slows down, causing a back up (back pressure) in the entire system. Now instead of scavenging (siphoning) out, the engine has to push out the exhaust. This takes horsepower away from the wheels.
    TRDCrewMax likes this.

  12. #11
    Hall of Fame Member Mr. Creosote's Avatar
    Join Date
    Apr 2006
    Location
    .
    Posts
    32,593
    Liked
    1526 times
    Rep Power
    268069

    Default Re: How a properly built exhaust system works

    Worse flow at lower rpms, but once the revs increase, scavenging can begin again. Had this experience with my MagnaDrone dual system. They use 2.5" tubing which seems to be a bit too big for a stock 5.7. It did wrap the tach needle over better, but so much torque was lost the truck would barely break traction off the line.
    Attention environmentalists, reduce emissions from this:

  13. #12
    Rookie
    Join Date
    May 2009
    Location
    california
    Posts
    3
    Liked
    0 times
    Rep Power
    0

    Default Re: How a properly built exhaust system works

    Great write up!! Hey Escotundra what muffler do you recomend??

  14. #13
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    any good flow through muffler, Borla, Magnaflow (a straight through not chambered) Gibson, BAMuffler.

    The thing that is most important when choosing a muffler is that the case, perf. tubing and end caps need to be 16GA or thicker. I bought a really awesome no name brand from PepBoys. All stainless, flow through. Sounded really good. Not too loud, but you could hear it. Nice deep pitch.

    One trip to Pismo and it got really loud and pieces of rusted metal began spitting out my tail pipe. It actually rusted through in a couple months. The outer case was 304 stainless (the best grade stainless there is) but the core was mild steel That's backwards! The core needs to be stainless, not necessarily 304 stainless, but mild steel 20GA is obviously going to rust.

    I didn't even check this stuff out when I bought it because I just assumed it was good. I was wrong! And I paid $100! I replaced it with a Borla and it lasted until I cut it open to see what was inside.

    All the best stuff is used! The mufflers that I built have many similarities! The only thing that I do different from Borla is the outer case isn't all pretty with 304 stainless. It's aluminized with 3/16" end caps. It would take years to rust through metal that thick. Plus, you can throw it out your window barreling down the freeway. If you can find it you'd still be able to install it. This thing is built like a tank. You can use em for rock sliders

    But like said before, I recommend a flow through style muffler, the same diameter as your stock tubing, 409 stainless core, about 12" long, packed with course fiberglass strands, with a 5" diameter body. Bigger is too much backpressure, smaller is not enough backpressure and it gets too loud as well.
    Last edited by escondidotundra; 05-08-2010 at 12:50 AM.

  15. #14
    cmb
    cmb is offline
    Veteran Member cmb's Avatar
    Join Date
    Jan 2005
    Location
    Cecil County MD
    Age
    61
    Posts
    711
    Liked
    22 times
    Images
    2
    Rep Power
    358

    Default Re: How a properly built exhaust system works

    What's your opinion on Corsa's Catback?

  16. #15
    Veteran Member escondidotundra's Avatar
    Join Date
    Jan 2008
    Location
    san diego, ca
    Posts
    1,161
    Liked
    385 times
    Rep Power
    9758
    Thread Starter

    Default Re: How a properly built exhaust system works

    I have heard real good things about the Corsa. I haven't seen a cat back for the first gen tundra in person so any information I gave would be opinion not first hand. The concept is great and makes a lot of sense. I haven't personally tested it so I can't really give any good advice.

    If you get one I'm sure everybody subscribed to this thread would love to see before and after dyno results. If you do it could you post the link here so we can see it? It would be nice to see another option for our trucks.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


LinkBacks (?)

  1. 10-08-2013, 06:09 PM
  2. 10-05-2013, 05:39 PM
  3. 09-12-2013, 06:00 PM
  4. 08-25-2013, 02:04 PM
  5. 08-15-2013, 12:31 PM
  6. 07-26-2013, 06:18 PM
  7. 05-31-2013, 09:05 AM
  8. 05-23-2013, 10:28 AM
  9. 10-30-2012, 08:20 PM
  10. 10-23-2012, 03:59 AM
  11. 10-16-2012, 11:27 AM
  12. 10-01-2012, 04:02 AM
  13. 09-27-2012, 08:48 AM
  14. 09-20-2012, 06:41 AM
  15. 09-19-2012, 11:01 AM
  16. 09-06-2012, 06:52 PM
  17. 08-24-2012, 09:52 AM
  18. 08-17-2012, 05:37 PM
  19. 08-07-2012, 01:57 PM
  20. 08-07-2012, 07:47 AM
  21. 08-02-2012, 04:34 PM
  22. 07-31-2012, 11:19 AM
  23. 07-30-2012, 11:47 AM
  24. 07-30-2012, 11:12 AM
  25. 07-24-2012, 10:06 PM
  26. 07-11-2012, 08:52 PM
  27. 07-02-2012, 06:29 AM
  28. 06-15-2012, 12:44 AM
  29. 06-12-2012, 11:38 AM
  30. 06-12-2012, 08:45 AM
  31. 06-10-2012, 04:46 PM
  32. 06-06-2012, 07:41 PM
  33. 06-01-2012, 06:46 AM
  34. 06-01-2012, 03:21 AM
  35. 05-20-2012, 06:49 PM
  36. 05-04-2012, 09:23 AM
  37. 03-04-2012, 09:32 PM
  38. 01-14-2012, 12:31 AM
  39. 12-06-2010, 05:47 AM
  40. 05-28-2010, 10:52 AM

Tags for this Thread

Posting Permissions

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