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Thread: EngMod2T Q&A

  1. #61
    Join Date
    4th December 2011 - 22:52
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    The "proposed" power possible or the "suggested" STA values are based on BMEP values. So even though power is shown the calculation is based on the BMEP value.

    It assumes very good scavenging and very good delivery ratios and very good trapping efficiency. It is what is possible if everything works as expected.

  2. #62
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    20th June 2020 - 07:10
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    As always, thank you for the great support

  3. #63
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    12th October 2016 - 01:24
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    I'm trying to model a single exhaust port where the side walls are not parallel (as pictured). my approach was to use a bridged exhaust with a bridge width of zero as this allows for a "side wall angle". The side wall angle is 22.6, but after saving and reopening this always gets lowered to 19.798. Also, the area in the STA screen shows NAN, so clearly it's not liking the numbers.

    Is this the best approach or is there a better way to go?

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    Patrick Owens
    www.OopsClunkThud.com

  4. #64
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    4th December 2011 - 22:52
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    There is a built-in limit to side wall angle. It is very conservative, I will update it to a less conservative value in the next day or two.

  5. #65
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    12th October 2016 - 01:24
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    Quote Originally Posted by Vannik View Post
    There is a built-in limit to side wall angle. It is very conservative, I will update it to a less conservative value in the next day or two.
    Thank you!

    spent some time today mapping out the cord width across the port, and it seems like that would drive the natural limit. the angle I had (22.6) was in excess of that limit (21.3) but that value is still larger than engmod lets you set.

    I could use the profiled type if need be, that would likely get around the issue, but not as clean.
    Patrick Owens
    www.OopsClunkThud.com

  6. #66
    Join Date
    8th December 2014 - 14:39
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    1980 Suzuki Gs1100E
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    SWPA
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    A new project!

    Hello Neels
    I've had your program for a couple of months but just now have time to play with it. I'm trying to model an old school engine ( single exhaust port, straight transfers, piston port) and I ran into a problem with the exhaust system. I started with the TZ 250g model and just changed the engine, some of the transfer info) I kept the TZ250g info when I didn't know the answer to some inputs because the engine I'm trying to model is very much like the TZ. In fact it is very much like the Yamaha 350 engine except for the reed intake. It's a Polaris 340 snowmobile race engine. Bore= 62mm, Stroke= 55.6mm, Rod center dist= 112mm but it has no boost port. When I put in the dimensions for the exhaust pipe then I try to run the sim it gives me a error code that says that this pipe will not work. I have checked my numbers a couple of time and cannot find the problem. I know the pipe works because I've used it racing. I do not have the file completed yet so I can not pack it, I don't think. Is there anything I can do?
    Thank you, Jeff Neilan

  7. #67
    Join Date
    4th December 2011 - 22:52
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    Hello Jeff,

    Two possibilities assuming you get the message from Dat2T and not EngMod2T:

    1. Try to pack it and if it does pack, email me the pack file.
    2. If it does not pack, open it with Dat2T, open the exhaust and save it, then save the project. Then, before opening Dat2T again, send me the following file: "C:\2Stroke\Dat2TErrorLog.dat"

    I will then see if I can find the issue.
    Kind regards
    Neels

  8. #68
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    8th December 2014 - 14:39
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    Thank you Neels I will try and see what happens. I let you know.

  9. #69
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    8th December 2014 - 14:39
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    1980 Suzuki Gs1100E
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    SWPA
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    file and paper

    Hello Neels
    Thank you for the paper you sent me about the Husky chainsaw. Do you have a file for your EngMod program that follows this paper? I would like to try to incorporate this t-model ex pipe into the handle as is suggested in their studies but I do not have a saw like this and I can find no one that has tried this. Thank you very much for your support and time. Jeff

  10. #70
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    4th December 2011 - 22:52
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    Hi Jeff,
    There is not enough info to accurately model it but I have a rough approximation of it. Do you want the pack file?
    Neels

  11. #71
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    8th December 2014 - 14:39
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    1980 Suzuki Gs1100E
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    pack file

    Hello Neels
    Yes I would like to see your file, thank you. Looking around I do not see and can not find many people that know about this style of tuning. Again, thank you!
    Jeff

  12. #72
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    4th December 2011 - 22:52
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    Okay, sent.

  13. #73
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    4th December 2011 - 22:52
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    The T-pipe discussed here is from SAE2001-01-1853 and looks like this:

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    To model it the following manifold is selected:

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    Then the following silencer is selected to add the box outlet with restricted outlet:

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    And then to get the box dimensions right:

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    Next the pipe dimensions and the collector junction has to be added.

  14. #74
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    8th December 2014 - 14:39
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    1980 Suzuki Gs1100E
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    SWPA
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    Husky pics

    Hello Neels
    Thank you very much for the pics explaining the T-pipe junction. Your pack file would not open but I managed to open the data file and I tried to model my own file but I was stuck about the T-pipe dimensions. Your pics really helped. I'll leave you know how it works. Thank you! Jeff

  15. #75
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    20th June 2020 - 07:10
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    When was the latest engmod2t suite update released? Not sure if I am up to date.

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