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Thread: ESE's works engine tuner

  1. #34951
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    It appears to me the hot gasses follow the outside radius of the pipe, while unburnt fuel tends to follow inner radius of the pipe. (Header early diffuser)

    A cylinder more susceptible to transfer/exhaust short circuiting is more likely to lose power with a twisty pipe over a straight one

  2. #34952
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    Quote Originally Posted by jonny quest View Post
    It appears to me the hot gasses follow the outside radius of the pipe, while unburnt fuel tends to follow inner radius of the pipe. (Header early diffuser)
    Flow through a pipe, especially unsteady compressible turbulent flow does not behave as we would think. The closest mind picture is that it forms two contra rotating cork screws going through the bend. The following pictures are a simplistic view of the process:

    Click image for larger version. 

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    A better reference is:

    https://macsphere.mcmaster.ca/handle/11375/21560

    The download is free.

    A bend does a very good job of mixing gas. Fuel droplets are not part of the gas and will probably accumulate on the outside of the bend.

  3. #34953
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    Quote Originally Posted by Vannik View Post
    Flow through a pipe, especially unsteady compressible turbulent flow does not behave as we would think. The closest mind picture is that it forms two contra rotating cork screws going through the bend. The following pictures are a simplistic view of the process:

    Click image for larger version. 

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ID:	348298 Click image for larger version. 

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    A better reference is:

    https://macsphere.mcmaster.ca/handle/11375/21560

    The download is free.

    A bend does a very good job of mixing gas. Fuel droplets are not part of the gas and will probably accumulate on the outside of the bend.


    I always get the vortex to start right after the bend when the pressure at the bottom decreases. has tried to change the CO2 level without major changes in results.
    They say that the source code in this program is used by several Formula 1 teams, perhaps McLaren
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

  4. #34954
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  5. #34955
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    FOS pipes I built made very excellent power on the very first pull on the dyno. Only 3hp shy of supposedly well developed pipes. These were built using the starting point 550 speed of sound variable. I feel as if there is gobs of power still left behind as this is version 1. I hope to model this engine and get a peak power egt from the donate-ee for simulations.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  6. #34956
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    Quote Originally Posted by Condyn View Post
    FOS pipes I built made very excellent power on the very first pull on the dyno. Only 3hp shy of supposedly well developed pipes. These were built using the starting point 550 speed of sound variable. I feel as if there is gobs of power still left behind as this is version 1. I hope to model this engine and get a peak power egt from the donate-ee for simulations.
    Glad to hear it, Condyn .

  7. #34957
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    Quote Originally Posted by Muhr View Post
    Here is a sim of 0mm radius 8mm and one ellipse./[/url]
    Did with a little help from a friend a test on bellmouth unfortunately on the wrong engine (for obvious reasons), but maybe can give an indication of what to expect.

    Engine: tm kz-R1
    Dyno: Dynostar
    EGT: Auto release 550 ° C
    Compensation: 0.025 hp / kmh driveline loss (shown as 0.03)
    Water temperature: 50c ° (external temperature controlled coolant)

    Test:

    Purple: With air box (Righetti)
    Green: Without +5 on jetting for the same EGT for all below
    Red: With little Bellmouth
    Blue: With huge Bellmouth
    Attached Thumbnails Attached Thumbnails Med (lila) vs utan (gron) vs l iten (röd) vs stor (Blå) BM.pdf  
    No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

  8. #34958
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    In dynamics, can the airbox add an unmeasurable addition to the dyno?

    The air being tranquilized and not subjected to the eddies and the speed of movement

  9. #34959
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    Quote Originally Posted by nitro2tfx View Post
    The next time I post I will post a screenshot of the pressure waves from a unique pipe we have used on 4 strokes. Yes I know nobody wants to hear about 4 strokes lol, but 2 stroke//4 stroke is not the point, the point of showing it is to show that a 2 stroke like exhaust pressure trace can be generated without using a 2 stroke type exhaust pipe and it can even be generated on a 4 stroke engine.
    EXHAUST TRACE FOR A TYPICAL 4-2-1 EXHAUST ON A 4 STROKE
    I know we aren't here to talk 4 strokes, but for reference sake, this is basically what an exhaust trace looks using a typical exhaust header design (on a 4 stroke).




    EXHAUST TRACE FOR UNIQUE CUSTOM EXHAUST ON THE VERY SAME 4 STROKE ENGINE
    This exhaust design generates a pressure trace that looks fairly similar to what is generated in a 2 stroke tuned pipe, BUT ths exhaust pipe looks nothing like a 2 stroke tuned pipe.


    So what is the point of posting this ? First, this unique custom exhaust design exists nowhere else but at TFX, it functions over a very wide rpm range and can generate a very intense low pressure. Second, the pressure trace looks a lot like a trace generated by a 2 stroke tuned pipe but it's design is completely different from that.

    Third, and the main point of posting this is that this is a 100% creative exhaust design, it looks nothing like that which is used on 2 stroke or 4 stroke engines. It was not arrived at by using simulation software, nor altering a 4 stroke design, nor altering a 2 stroke design. Thge general design was literally pulled out of thin air using some creative thinking and logic, then made to work using real time exhaust pressure data. This very same general design could be fabricated in any number of different ways in terms of specific dimensions and 99 % of them will not work (as we learned lol). The reason we were able to arrive at the working version is because we had real time exhaust pressure data and could see where we were going wrong and the direction we needed to take to get where we hoped (I say "hoped" because we had never been there) to go. The design exceeded our hopes. This is an example of the "C" I was talking about previously when I mentioned that simulation software will get you from A to B quickly, but real time pressure data can get you from B to C even when you don't know if "C" exists, no matter what you design real time pressure data shows you what you have and you can see where you need to go.

  10. #34960
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    Well here we go again with me disagreeing and thinking in a completely differnt tangent to you Nitro.
    What you have shown with the 4 stroke plot is simply what has been documented in many SAE papers describing what is needed , and comparing TFX data to simulation data to prove it.
    Perfect example is SAE 2001 01 1797/4218.
    This showed real time data against Optimum Power Technolgy's 4 stroke sim package ( I can use that as its free to Uni engineering depts )
    Testing a straight pipe Vs a pipe/diffuser combination.
    4Ts exhausts are simpler in that there are two effects that can contribute to power , pulling as wide and as deep a depression around TDC overlap as possible , and secondly a strengthening leftward
    depression during the EVO period to reduce exhaust stroke pumping losses.

    Achieving both together can accentuate peak power , spreading the two effects out favours powerband ( torque ) width.
    Saying that achieving that plot could not be done just using a sim package is narrow minded rubbish - again it comes back to interpreting the data , and intellectual accuity in coming up with innovative
    solutions to generate the desired end result.
    Its easy to see on that plot that achieving even greater depression , sooner , between - 150 and -30 would reduce pumping losses during EVO. I dont need real data to see that trend at all.

    The result certainly isnt limited by the sims ability to represent vey accurately the real time data - the big differnce being the time and work involved is exponentially less the harder the task at hand is.
    Sadly for 4T tuning the exhaust plays second fiddle big time to the gains achievable with inlet tuning , the complete reverse of a 2T.
    Variable length Exhaust = big 2T power , variable length Inlet = big 4T power.

    EDIT - I could not resist adding a reply to this quote " I know we aren't here to talk 4 strokes, but for reference sake, this is basically what an exhaust trace looks using a typical exhaust header design (on a 4 stroke)."

    That pressure trace result is NOT from a typical exhaust header , its a completely wrong example , there is virtually no help with exhaust stroke pumping losses , and there is virtually no depression around TDC overlap
    ie that pipe setup is NOT tuned correctly to the chosen rpm.
    The super secret setup IS tuned correctly so will obviously produce superior pressure trace shape and power as a result.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

  11. #34961
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    Sadly for 4T tuning the exhaust plays second fiddle big time to the gains achievable with inlet tuning , the complete reverse of a 2T.

    Think Wobb if you have time for it !!!!!!!!

  12. #34962
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  13. #34963
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  14. #34964
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    Quote Originally Posted by nitro2tfx View Post
    EXHAUST TRACE FOR UNIQUE CUSTOM EXHAUST ON THE VERY SAME 4 STROKE ENGINE
    This exhaust design generates a pressure trace that looks fairly similar to what is generated in a 2 stroke tuned pipe, BUT the exhaust pipe looks nothing like a 2 stroke tuned pipe.
    Nitro,

    That is a truly amazing trace. More so on a 4T engine. I know you do not want to disclose how you achieve it but is there a way we can do an NDA so I can test to see if a sim can duplicate it?

    It does seem that there are a number of steep wave fronts in there. Very interesting.

  15. #34965
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    Well Dutch you have me by the balls , I read it twenty times , and thought on it all night.
    If you fuckup the Exhaust on a 4T but have a perfect inlet system it will make around 70% of its power capability.
    If you completely fuckup a 2T Exhaust , but have a perfectly developed inlet system it will make around 30% of its capability.
    Is that not what I was saying, or am I so blind I cant see the woords for the trees.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

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