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Virtual Dyno


gotsugg

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  • 1 month later...

If you send me the specs on a couple of LGT Ill support them.

 

Send me the cars information in the following format:

 

<CarMake>Subaru</CarMake>

<CarModel>Legacy 2.5i SE 07 (auto)</CarModel>

 

<Weight>3325</Weight>

 

<TransGear3>1.000</TransGear3>

 

<TransGear4>0.694</TransGear4>

 

<FinalGearRatio>4.111</FinalGearRatio>

 

<DragCoefficient>0.33</DragCoefficient>

 

<FrontalArea>22.00</FrontalArea>

 

<TireDiameter>25.07</TireDiameter>

 

 

Look forward to supporting all the Legacy GTs.

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  • 3 weeks later...

Is this what you need then? I think most specs would be the same as the 2.5i, other than the manual gear ratios I changed.

 

<CarMake>Subaru</CarMake>

<CarModel>Legacy 2.5GT 05 (MANUAL)</CarModel>

<Weight>3325</Weight>

<TransGear3>1.296</TransGear3>

<TransGear4>0.972</TransGear4>

<FinalGearRatio>4.111</FinalGearRatio>

<DragCoefficient>0.33</DragCoefficient>

<FrontalArea>22.00</FrontalArea>

<TireDiameter>25.07</TireDiameter>

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I just dont have the time to browse sites to support new cars. I am working on my Masters in Nursing and time is scarce. If someone would gather the data and combine the replicated data (years that have the same specs say 05-08) When you get a few cars get them to me and Ill support a chunk at a time. That is the quickest way to get a bunch supported. Someone want to volunteer?

 

Let me know.

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  • 3 months later...

Is there any possible way to make it work properly with an auto tranny? any compensation for the torque converter lockup? I've input all the accurate data including final drive and 3rd gear ratio with a 2k-6k 3rd gear pull, can't get the numbers to be somewhat believable...

 

car: 2008 LGT 5EAT

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not really ... can you think of a way to take a slipping clutch into account ... thats about the same enigma. Something that we can see but how to find it by looking at the data is hard.

Have you had a look at Airboy's spreadsheet? His strategy is to use logged vehicle speed data to calculate engine speed from gear ratio (assuming locked TC) and acceleration from that calculated RPM against the time stamps. Calculate torque from acceleration and mass as usual.

 

... at least that's how I understand it.

Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Have you had a look at Airboy's spreadsheet? His strategy is to use logged vehicle speed data to calculate engine speed from gear ratio (assuming locked TC) and acceleration from that calculated RPM against the time stamps. Calculate torque from acceleration and mass as usual.

 

... at least that's how I understand it.

 

 

it seems airboy shows the same issue with a tc lockup... making the graph look better is one thing but the numbers is another... all the smoothing in the world can mask it but the hp/tq comes out wacky tabacky,

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Yes, the spool area and everything up until lockup will be smoothed and wacky but post lockup should read like a manual.
Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs.
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Have you had a look at Airboy's spreadsheet? His strategy is to use logged vehicle speed data to calculate engine speed from gear ratio (assuming locked TC) and acceleration from that calculated RPM against the time stamps. Calculate torque from acceleration and mass as usual.

 

... at least that's how I understand it.

 

For the most part, this is correct.

 

If you have experimental data (speed and time), then you don't have to account for aero, it's included. But there is a tire-balloon effect that isn't accounted for.

 

You can account for slip (either wheel spin, or Torque converter) by noting engine RPM and working engine RPM out of wheel speed and gear ratios. The difference in the two will be your "slip factor", and you can move forward from that.

[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
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I agree with the fact that you can smooth it all you want and mask all the peaks but you will still have the same problem just masked. To get an accurate number you can NOT factor in the torque converter ... it MUST be locked to get an accurate number. It would be the same as trying to figure in clutch slipping or wheel spin. Its IMPOSSIBLE to figure accurately. It would be about as accurate as asking the magic eight ball ... Its just that simple.
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I agree with the fact that you can smooth it all you want and mask all the peaks but you will still have the same problem just masked. To get an accurate number you can NOT factor in the torque converter ... it MUST be locked to get an accurate number. It would be the same as trying to figure in clutch slipping or wheel spin. Its IMPOSSIBLE to figure accurately. It would be about as accurate as asking the magic eight ball ... Its just that simple.

 

You can calculate torque through a slip system. You just have to know more about the system. I'd have to spend some time thinking about it, but I know it can be done.

[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
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If you think of a way let me know. I dont see how you can calculate slip since its always changing. Im not saying it cant be done ... Ill change what I said to say that I dont know how you can calculate it.
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If you think of a way let me know. I dont see how you can calculate slip since its always changing. Im not saying it cant be done ... Ill change what I said to say that I dont know how you can calculate it.

 

I'll see if I can find some time to help come up with a solution. I'll pm you and we can talk about it.

[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
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is virtual dyno suppose to measure wheel numbers or crank? here is my graph with a 3rd gear pull 2k-6k on a 60 degree day corrected, all ratios corrected in xml file, weights exact, wheel diameter exact. 08 LGT 5eat

 

my 3rd gear log is also included

 

Classic case of torque converter not locked up.

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