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Unreal performance, Power levels, Torque and EGT limits. Please adress this issues.


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Greetings to all the members on this community, I'd like to adress an issue that is the most important of a airplane and it is: Performance, since the beggining of this beatiful TOGASIM product there has been a problem with how the TPE331-10-501M/-511M performs, basically the power levers get to the mehcanical stop very early in the climb, in real life that's not the case, the turbines will limit by torque and later by EGT depending on the conditions and is the pilot's work to manage those limit with the power level wich will have plenty of room for movement (if you take them to the top you just blow the TPE).

this not only make the operation of the engines a fake situation but most important affects the performance of the plane, right now we have a MU2 with a performance of a Twincommander 690 whith -5 TPE's engines 

255/265 TAS

The MU is a 300kts TAS plane. 

So far it's imposible to make a "real flight" beacause there isnt a reference for what the model do. 

I know it's hard for the developer but I think that in a simulation the reality is a lot, a very big lot more important than looks or details that make users "confortable" 

the plane is the way it is and it should be portrayed as.

 this gorgeus model is just to one step to be perfect and to be one of the most iconic products ever produce to Xplane.

 

Isaac Martínez

CPL

AC90 pilot

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  • 2 weeks later...
On 9/6/2023 at 11:55 PM, Isaac Martinez said:

but I think that

but many many more people don't think that.   BUT.....to your point....I agree that the performance model needs to be improved!  Its a laborious process that involves a lot of flight testing...and for the Moo, that time isn't recouped financially.   So....I have to approach it after I handle the things that genreate the revenue statistically.  Its never been ideal for the hard-core performance guys I admit...but I do agree with you that it needs work.

-tk

 

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In my testing (4 bladed prop) , numbers seem spot on to me, performance wise. 

Test Conditions:

-FL280
-40C (ISA at FL280)
-ISA Barometric Pressure

Throttle Max/Props Adjusted to 650C ITTs

Results 280 KTAS/ FF ~400lbs. (Fuel flow is about 64lbs too low, pretty close though)image.thumb.png.ee93545fa8cd8acedc18b507fee414dc.png

I'm comparing my results to this brochure advertisement:
image.png.3c9479e8edab5f3948670c36142d2732.png

Edited by Hawkeye91
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Cruise power isn't too far off (though it depends a bit on altitude, and not all parameters will hit the POM values):

image.thumb.png.39efafba1b5d2c380ed673fed29cabe3.png

Getting those all dialed in will possibly not work - there are also tables for ISA +/- 10, 20 and 30, and then the same for max range power (the one above is for recommended cruise, i.e. pretty much the maximum you can get from those TPEs). In total there are nearly 1,300 different altitudes, temperatures and power settings to be dialed in (108 table lines * 3 weights * 2 different power settings * 2 different props (4 & 5 blade)), and for each you'd have to align four data points (torque, ITT, fuel flow, airspeed), so a total of over 5,000 data points.

With the way X-Plane's engine, prop, lift and drag models work, I don't see this is close to possible - you can nail one setting by tweaking the fuselage shape, airfoils, engine and prop parameters and curves, but that will most likely throw you off course for another data point. So Tom's dilemma here will be that he has to chose which data points to align to, and accept that others will be somewhat off.

If I understood Isaac correctly though, he was more addressing the engine limits in climb (first they're torque limited, later on they're temperature limited) - that'd be the next >5,000 data points to pin down...

Finally, I'd like to say these discussions here sometimes come across as if we only had to criticize the Moo - we're so much quicker in reporting issues and bugs than being grateful for how great a Moo model Tom created here. Tom, if you read this, the MU v2 is great and deserves more visibility in public (and more sales). It is by a huge margin the aircraft model I fly and enjoy the most ever since it released for XP12.

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There's no doubt the engine model needs some work.  This is simply a matter of 'business triage'.  

On 9/6/2023 at 11:55 PM, Isaac Martinez said:

I'd like to address an issue that is the most important of a airplane

there is some truth here; however, one could rephrase to say,  " the most important issue of a .......flight simulation experience for enjoyment" is NOT the performance!  A great many number of simmers enjoy the more visceral aspects of simming..."sights / sounds / perception of flying / visual stimuli", rather than the performance.   The airliners certainly attract simmers who enjoy the cognitive and intellectual aspects of simming, ergo the performance aspects of those classes of products,  but for GA aircraft?  its is a very small percentage of users who are "by the book"...and that simply doesn't pay the bills for the work involved.

I definitely will come back to the Moo engine model at some point....and I won't charge any hidden fees when I do, but from a strategic perspective, its simply having to wait its turn.  But your points are noted and I've logged this post to revisit.

-tk

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20 minutes ago, OneOffRegistrationUser said:

Well, I'm personally do not mind to pay extra for updated Moo. And saying that I do not event expecting anything new, just current issue-log cleared.

I’m of this mind too. I’ve spent thousands on this hobby. I’m always willing to pay for devs works and don’t expect them to work for free. 

Edited by Hawkeye91
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  • 3 months later...

none to speak of.  I did spend some time trying out Captain Crashes "fixes"; however,  I found out that he only tested in "cruise conditions" to "match numbers", because he had charts with numbers......but in doing so.....using his new prop / engine settings, the plane is completely inaccurate for ground ops, with insufficient thrust for taxi without going well into the alpha region.  When I asked him about this he said, "no, I didn't test on the ground"....DOH...  This is why I'm generally roll my eyes at community members with "fixes"....their perspective is usually very one dimensional, only regarding whatever it is they are passionate about. but the whole of the system is very inter-dependent.

I'm keeping part of his work, and dismissing other parts..and its a parameter by parameter evaluation.   So sorry..no news yet, but certainly the work is still in my inbox.

TK

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On 1/11/2024 at 11:52 AM, tkyler said:

none to speak of.  I did spend some time trying out Captain Crashes "fixes"; however,  I found out that he only tested in "cruise conditions" to "match numbers", because he had charts with numbers......but in doing so.....using his new prop / engine settings, the plane is completely inaccurate for ground ops, with insufficient thrust for taxi without going well into the alpha region.  When I asked him about this he said, "no, I didn't test on the ground"....DOH...  This is why I'm generally roll my eyes at community members with "fixes"....their perspective is usually very one dimensional, only regarding whatever it is they are passionate about. but the whole of the system is very inter-dependent.

I'm keeping part of his work, and dismissing other parts..and its a parameter by parameter evaluation.   So sorry..no news yet, but certainly the work is still in my inbox.

TK

Ouch. Thanks Tom, can't say this makes me want continue to contribute or feel valued in your community. Well I wouldn't say it's my work that's the problem it lies more with the governor and stock engine model. I followed the overhaul manual for both blade profile and airfoil from hartzell. And I tested in the air because there is no data for "ground handling". Thanks, crash

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3 hours ago, CaptCrash said:

Thanks Tom, can't say this makes me want continue to contribute or feel valued in your community

I know how you feel Mike....I felt a similar sting reading your comments on Toto's Discord a while back,  insinuting a simple swap from your work to mine would "make eveything OK" and I was just too lazy to do it....and clearly my defensive posture resulted in a harsh turn of phrase above..which doesn't make it right.  At the end of the day though, we get the customer support emails (a much larger contingent than is present on forums)  and as such, I have a broader perspective of my customer base ...and enough experience in this market to know that your changes would result in making several customers happier, but also several more disappointed and I have to answer to those folks.

I'm sorry if it stung a bit.   What we're dealing with here is a "philosophy of development" given known limitations in 'modeling methodology'.   For a good while I've watched us aircraft devs "put in the numbers" and complain to Austin when things don't perform right.  But at the end of the day, these are just a big collection of numerical models and approximations, some better than others depending on lots of factors. So as aircraft devs with 'approximate models' in many places, we've always had to determine "which numbers to prioritize"  given the state of X-Plane's flight/systems models.  If, for example, you prioritize "accurate blade angles and engine parameters per handbooks" but the plane's performance is off in some regime because X-Plane's 'black box models' are off or too generic in places ....then you have to ask yourself, "can a user see the blade twist angles of the flight model? ..... or can a user more easily see the "off-nominal performance" and you make your decision about what to prioritize and compromise.  If I said, "I'm putting in all the accurate numbers and will wait for X-Plane to 'come to me' and perform correctly before I release the product....well..you can imagine how that will go, so my philosophy is different.  Numerical compromises and fudges are required for more balanced performance across the envelope in my experience. 

Indeed you have put in a crazy amount of accurate info into Plane-maker, and I do appreciate your work and it won't go to waste.  It is not a simple swap and deploy because as you've noted, the X-Plane models aren't perfect so some numbers will have to change to accomodate the ground regime; however, your work is a wonderful springboard that I do respect and will simply have to look at parameter by parameter and gauge the effect against their impacts in a broader range of regimes.   I hope I can strike a balance that satisfies enough.

-tkyler

 

 

Edited by tkyler
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5 hours ago, tkyler said:

 

I know how you feel Mike....I felt a similar sting reading your comments on Toto's Discord a while back,  insinuting a simple swap from your work to mine would "make eveything OK" and I was just too lazy to do it....and clearly my defensive posture resulted in a harsh turn of phrase above..which doesn't make it right.  At the end of the day though, we get the customer support emails (a much larger contingent than is present on forums)  and as such, I have a broader perspective of my customer base ...and enough experience in this market to know that your changes would result in making several customers happier, but also several more disappointed and I have to answer to those folks.

I'm sorry if it stung a bit.   What we're dealing with here is a "philosophy of development" given known limitations in 'modeling methodology'.   For a good while I've watched us aircraft devs "put in the numbers" and complain to Austin when things don't perform right.  But at the end of the day, these are just a big collection of numerical models and approximations, some better than others depending on lots of factors. So as aircraft devs with 'approximate models' in many places, we've always had to determine "which numbers to prioritize"  given the state of X-Plane's flight/systems models.  If, for example, you prioritize "accurate blade angles and engine parameters per handbooks" but the plane's performance is off in some regime because X-Plane's 'black box models' are off or too generic in places ....then you have to ask yourself, "can a user see the blade twist angles of the flight model? ..... or can a user more easily see the "off-nominal performance" and you make your decision about what to prioritize and compromise.  If I said, "I'm putting in all the accurate numbers and will wait for X-Plane to 'come to me' and perform correctly before I release the product....well..you can imagine how that will go, so my philosophy is different.  Numerical compromises and fudges are required for more balanced performance across the envelope in my experience. 

Indeed you have put in a crazy amount of accurate info into Plane-maker, and I do appreciate your work and it won't go to waste.  It is not a simple swap and deploy because as you've noted, the X-Plane models aren't perfect so some numbers will have to change to accomodate the ground regime; however, your work is a wonderful springboard that I do respect and will simply have to look at parameter by parameter and gauge the effect against their impacts in a broader range of regimes.   I hope I can strike a balance that satisfies enough.

-tkyler

 

 

My sincere apologies for making any inference that you were not being proactive toward the development of the MU-2.

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