1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Headers and exhaust

Discussion in 'Performance and Tuning' started by sullivan4987, Apr 11, 2016.

  1. Apr 11, 2016 at 9:19 AM
    #1
    sullivan4987

    sullivan4987 [OP] Well-Known Member

    Joined:
    Jul 1, 2013
    Member:
    #107401
    Messages:
    126
    Gender:
    Male
    Boulder
    Vehicle:
    09 Tacoma TRD OFF ROAD v6 4x4 access cab
    OME 3.5 inch Heavy Duty lift, BFG T/A 285 75 16, on board ARB compressor, ARB bumper with fogs and drive lights, custom on board switches, Line X flares, grill, rear bumper, body frame cat back exhaust
    if I want to replace my headers and exhaust for power gains on both ends, what is the best combination ? I've learned that long tube headers are best over shorties but getting the exhaust pipe diameter and its shape (straight long or Y ) are important so as not to loose power or torque on either end. What have you all done and feel that torque and hp increased on both ends?
     
  2. Apr 12, 2016 at 2:50 PM
    #2
    StuckinOhio

    StuckinOhio Well-Known Member

    Joined:
    Oct 30, 2011
    Member:
    #66154
    Messages:
    418
    Gender:
    Male
    First Name:
    Mark
    Ohio
    Vehicle:
    12' v6 AC 4x4 SR5
    The stock diameter is more than sufficient for flow unless you supercharge.
    The things I learned installing aftermarket headers and y pipe with a stock cat-back on my truck are:
    A N/A 1gr needs back-pressure for torque.
    Adding a URD y pipe with stock headers took a little low-end away but allowed the exhaust gases to exit faster and allowed the truck to pull harder once the rpms were over 2k.
    After installing shorty headers with high flow cats I learned I had Almost no back pressure and truck was an absolute dog to drive. I ended up putting stock y pipe back on to make my truck usable for towing. Although a more expensive option I think the short tubes are the way to go if you want torque or need to tow. Especially if you don't plan on supercharging. Many members have long tube because they have been out on the market for awhile and there are a few different brands out there. All of the short tube header options were to cannibalize stock headers and weld stock cats back onto a new exhaust manifold. Which is a ton more work than remove and replace.
    This was until last year or so AFE came out with a full shorty replacement. From my understanding long tubes shift powerband up and the gains are in the mid to high rpm range. The other header option is the URD equal length headers which claims gains on both ends. Lastly, regardless of tube type, header install is somewhat difficult since it is not full size engine bay. Install for me was about 10 hrs.
    This was the experience / knowledge I learned throughout the process.
    Hope it helps, if not take it with a grain of salt.
     
    MadDaddy likes this.
  3. Apr 26, 2016 at 10:13 AM
    #3
    howl686

    howl686 New Member

    Joined:
    Mar 29, 2016
    Member:
    #182696
    Messages:
    3
    Gender:
    Male
    Vehicle:
    2003 Green Tacoma 5lug
    New here but have some experience with hondas. You don't want back pressure. that is still a restriction.
    you want good exhaust velocity. You ever water your grass and put your thumb on the end. or better yet have a nozzle?
    the water goes further with a smaller flow point. too much pressure and you're down to a trickle but the right amount you can reach the whole yard without having to walk.
    Some cat-backs increase the piping diameter and thats why you see less torque on the low end. and when the engine is going and pumping more air out the exhaust you feel more power. that is because the piping size fits well for that amount of airflow.

    But you're right N/A will not get much in terms of gains if any from wider/ less restrictive piping because its not pumping out as much eshaust as a S/C would
     
  4. Apr 26, 2016 at 7:06 PM
    #4
    StuckinOhio

    StuckinOhio Well-Known Member

    Joined:
    Oct 30, 2011
    Member:
    #66154
    Messages:
    418
    Gender:
    Male
    First Name:
    Mark
    Ohio
    Vehicle:
    12' v6 AC 4x4 SR5
    I am confused by your statement...
    restricting the flow out of a garden hose is creating back pressure in the hose.
    Yes it increases your exit velocity but you also decreasing through-put volume, the water velocity in the hose is also decreased
    If my truck was a manual and i could control engine speed independent of vehicle speed it would be different
    With just headers, no y pipe, nothing, I could barely get the truck moving and there was no pedal response. It doesn't get much more free flowing than that.
    I'm not expecting max torque at low rpm, but eliminating all the restrictions significantly dropped torque output to the point where my truck was un-useable.
    When the light turns green and im at 715rpm (idle) and try to accelerate to 2200rpm, the truck acted like a slug to hit 45mph.
    By installing some of the stock restrictions back on it improved low end performance and returned the drivability.
    Hondas aren't known for their torque nor were they designed for towing or hauling.
    Honda's just start to get into their power band at 3000 rpm. which at that point, the exhaust gas velocity has already been accelerated from idle.
    Any restrictions at that point (from 3000-7000) that slow exhaust gas velocity and would hurt the performance.
    This does not seem to be the case from my experience with the 4.0L
     
  5. Apr 26, 2016 at 7:39 PM
    #5
    howl686

    howl686 New Member

    Joined:
    Mar 29, 2016
    Member:
    #182696
    Messages:
    3
    Gender:
    Male
    Vehicle:
    2003 Green Tacoma 5lug
    Sorry I did a terrible job at summarizing but I was trying to say is covered in this article: http://crxcommunity.com/viewtopic.php?t=318
    But you're right by the time my honda would get going my rpms were up there. so that may be why it feels different on my end
     
    Last edited: Apr 26, 2016
  6. Apr 27, 2016 at 8:52 AM
    #6
    sullivan4987

    sullivan4987 [OP] Well-Known Member

    Joined:
    Jul 1, 2013
    Member:
    #107401
    Messages:
    126
    Gender:
    Male
    Boulder
    Vehicle:
    09 Tacoma TRD OFF ROAD v6 4x4 access cab
    OME 3.5 inch Heavy Duty lift, BFG T/A 285 75 16, on board ARB compressor, ARB bumper with fogs and drive lights, custom on board switches, Line X flares, grill, rear bumper, body frame cat back exhaust
    Thanks for your thoughts, guys. I just want to know what header and mag flow ( 40 or 50? ) would work for what I am seeking. I should mention too that I do love the sound I got from my mag flow last time I had one. Now I want to do headers for added power while also having the nice throaty sound from the after market exhaust. I don't want to pay to have something done only to learn that I have lost a bunch of power. I would like to see gains on both ends with after market exhaust and after market headers. Thanks again for all you have shared !!
     

Products Discussed in

To Top