Brad Barnhill's Virtual Dyno with HP Tuners

[TiredGXP]

Virtual Dyno doesn't really like that log:

Attachment 27665

The other tool gives about the same result as your last log:

Attachment 27666

The .txt format of the log removes a bit of precision from the time stamp. If you export your log to a .csv format, then you can get a bit more precision on the time stamp by formatting the cells to [mm:ss.000] when opening it in excel. As it is, you only see data to the nearest tenth of a second, which can skew the results a bit.

I charted the change in rpm between data points. note the big drop just before 5500 rpm, this coincides with the bottom of the trough in the virtual dyno plot (much easier to see at a lower level of smoothing). One more significant digit in the time stamp may well have eliminated this dip all together.

Attachment 27667

[SargeZ06]

Virtual Dyno doesn't really like that log:

Attachment 27665

The other tool gives about the same result as your last log:

Attachment 27666

The .txt format of the log removes a bit of precision from the time stamp. If you export your log to a .csv format, then you can get a bit more precision on the time stamp by formatting the cells to [mm:ss.000] when opening it in excel. As it is, you only see data to the nearest tenth of a second, which can skew the results a bit.

I charted the change in rpm between data points. note the big drop just before 5500 rpm, this coincides with the bottom of the trough in the virtual dyno plot (much easier to see at a lower level of smoothing). One more significant digit in the time stamp may well have eliminated this dip all together.

Attachment 27667

It won't let me upload CSV files to this website so I had to convert it to .txt.

[SargeZ06]

Here I will just upload the .xlsx and let you guys see if you can make it work.

nitrous pull. Can't remember if this was a 125 or 150 shot.

[TiredGXP]

There's like only 9 WOT data points in the log, tough to get anything meaningful, especially with such a low gear.

Based on the speed in the log, this must have been a second gear run. Second gear is 2.07?

You might want to check on the drag coefficient. Some web sources indicate it's 0.31, not 0.373 as previously posted. 0.31 makes more sense - it's a 'vette, not a truck.

Can you confirm what your rear tire size is? Maybe you've changed them, but stock rear tires were 295/35-18 (may be model year specific), which yields a tire diameter of 26.13, not 25.5.

At any rate, this log only gives a result of 335hp using second gear of 2.07, Cd of .31, and tire of 26.13" diameter (correction factor of 1).

[miami993c297]

This is the engine dyno power curve:



from this dyno session (click on the image):



On 03/21/11 I went on my usual private road, flat with no elevation on 3 miles, recorded my DA with the stationary weather station, weighted the car before the run ( I know it's not on the light side...), and launched my 4th gear WOT from ~2500 rpm to ~ 7250 rpm...all temperatures monitored.
For this purpose the car was tune in "race trim" which is not something I would run everyday...

The results from Brad Virtual Dyno are making sense to me as the drive-train loss on the Dynojet was 64 RWHP...adding that amount to the power curve below and we are pretty close of the engine power...
Nonetheless, the power difference above 6500 rpm is certainly a consequence of the full racing open headers on dyno and no air filter, versus a complete full exhaust and air filter in vivo...just my guess!!!
Obviously, those are SAE corrected numbers:



Now, let's speak of the real measured power to the groung this precise day, and have a look to this power curve not corrected:



Again it is making a complete sense as now we can analyse my usual time sheet for this run...the starting speed is ~66 mph @ ~3000 rpm at the start of the run and ~159 mph @ ~7250 rpm by the end of the run, GPS measured:



I find this software easy to work with, repeatable, and makes the analyse so convenient on the dot...and it gives the all community the opportunity to compare and overlay our engine data with a lot of accuracy.

Christian

[SargeZ06]

There's like only 9 WOT data points in the log, tough to get anything meaningful, especially with such a low gear.

Based on the speed in the log, this must have been a second gear run. Second gear is 2.07?

You might want to check on the drag coefficient. Some web sources indicate it's 0.31, not 0.373 as previously posted. 0.31 makes more sense - it's a 'vette, not a truck.

Can you confirm what your rear tire size is? Maybe you've changed them, but stock rear tires were 295/35-18 (may be model year specific), which yields a tire diameter of 26.13, not 25.5.

At any rate, this log only gives a result of 335hp using second gear of 2.07, Cd of .31, and tire of 26.13" diameter (correction factor of 1).

No way I can do 100mph in second. Has to be 3rd gear. Tire is not stock. It's a Mickey Thompson 315/35-18 which is 25.5".

How do I get more data points?

0.31 is probably good.

[Leafy]

No way I can do 100mph in second. Has to be 3rd gear. Tire is not stock. It's a Mickey Thompson 315/35-18 which is 25.5".

How do I get more data points?

0.31 is probably good.

Get more data point by logging less pids. I believe that should work if I remember the instructions/help file/faq for hp tuners.

[miami993c297]

Get more data point by logging less pids. I believe that should work if I remember the instructions/help file/faq for hp tuners.

That simple...

Christian

[TiredGXP]

No way I can do 100mph in second. Has to be 3rd gear. Tire is not stock. It's a Mickey Thompson 315/35-18 which is 25.5".

How do I get more data points?

0.31 is probably good.

The data file you posted shows 64 mph during the full throttle run, which seems about right for 6010 rpm in second gear with those tires. Maybe you posted the wrong log file.

You only really need to log RPM to make this work. Logging fewer pids really increases the frame rate, although HPT gets a bit erratic at high refresh rates. Plus, third gear will ramp up slower than second.

[SargeZ06]

The data file you posted shows 64 mph during the full throttle run, which seems about right for 6010 rpm in second gear with those tires. Maybe you posted the wrong log file.

You only really need to log RPM to make this work. Logging fewer pids really increases the frame rate, although HPT gets a bit erratic at high refresh rates. Plus, third gear will ramp up slower than second.

I'll log a new run when it dries out. Raining all day here.

[bbarnhill]

You really need three things.

Time which isnt a pid, RPM and TPS. Go ahead and grab TPS that lets the program auto trim your run. Otherwise youll be tasked with trimming it by hand and that sucks.

I do see that the legend for the graph was falling off the bottom and if you add more runs it starts creeping up the page. I want you to know that I have that fixed in the next release. There are a PAGE full of changes that got made. A lot of the changes are 'under the hood' but they help with maintaining this application over the long haul. I did make some noticeable changes and I hope to get this new release out soon. It will even check the web for an update when it has internet access so you dont have to constantly worry you have an old version. (Should have added that long ago but I just got time to get that done).

If you guys need anything you know Im here to help anyway that I can. Ill keep you guys posted on the next release coming which is going to be 1.1.0, its a pretty big release.

[SargeZ06]

You really need three things.

Time which isnt a pid, RPM and TPS. Go ahead and grab TPS that lets the program auto trim your run. Otherwise youll be tasked with trimming it by hand and that sucks.

I do see that the legend for the graph was falling off the bottom and if you add more runs it starts creeping up the page. I want you to know that I have that fixed in the next release. There are a PAGE full of changes that got made. A lot of the changes are 'under the hood' but they help with maintaining this application over the long haul. I did make some noticeable changes and I hope to get this new release out soon. It will even check the web for an update when it has internet access so you dont have to constantly worry you have an old version. (Should have added that long ago but I just got time to get that done).

If you guys need anything you know Im here to help anyway that I can. Ill keep you guys posted on the next release coming which is going to be 1.1.0, its a pretty big release.

Oh does it parse the file to only look at 100% TPS?

[Leafy]

Oh does it parse the file to only look at 100% TPS?

Yes, but you can choose to have it not. And I believe set a threshold as to whats considered 100%, if that feature's not in there it should be.

[bbarnhill]

No its not in there ... it automatically figures out what the highest TPS in the file is and figures out the WOT section of the log. So there is no need to input any value

[shizon]

I've used it on a couple cars and it has been really accurate. I'm going to use it on a h/c LS3 camaro next week.

Any beta I can try for you? Maybe one that doesn't require me to delete the first 7 rows in excel from the export from the scanner?

[bbarnhill]

send me an export before you edit it.

If its a normal HP Tuners export you shouldnt have to delete those lines. If its a log format that I havent seen maybe but I have several logs and none of them have the header deleted out.

[T-Man]

315/401 from Brads Virtual Dyno

DJ showed 311/360

Pretty close! Thanks Brad!

[bbarnhill]

Sometimes depending on the dyno and the smoothing applied there can be a difference. Make sure you dont have a spike or something.

[T-Man]

Sometimes depending on the dyno and the smoothing applied there can be a difference. Make sure you dont have a spike or something.

Nature of my boosted ride. Graph was almost identical to the real deal.

Appreciate the time you spent on this Brad!

[buldogg]

I've just tuned a C5 Z06 with Headers / Induction
Ive tried your program.
I've got a dyno sheet of the same car Induction Tuned. (without headers)


<?xml version="1.0" standalone="yes"?>
<CarDataset xmlns="http://tempuri.org/CarDataset.xsd">
<CarParameters>
<CarMake>Chevy</CarMake>
<CarModel>Corvette C5 Z06</CarModel>
<Weight>3115</Weight>
<TransGear3>1.43</TransGear3>
<TransGear4>1.00</TransGear4>
<FinalGearRatio>3.42</FinalGearRatio>
<DragCoefficient>0.29</DragCoefficient>
<FrontalArea>20.47</FrontalArea>
<TireDiameter>26</TireDiameter>
</CarParameters>
</CarDataset>



Here is the dyno without headers (dynoflow dyno)
342 RWHP

Im sorry if Im late to the party but Ive just started playing with this today and everywhere I have looked it shows the 3rd gear ratio for your car is 1.30 I might be wrong but when I use this xml file it gets with in 10 hp of the actual dyno try this and see if it helps I est your weight as 3250 with driver.

<?xml version="1.0" standalone="yes"?>
<CarDataset xmlns="http://tempuri.org/CarDataset.xsd">
<CarParameters>
<CarMake>Chevy</CarMake>
<CarModel>Corvette C5(Manual)</CarModel>
<Weight>3300</Weight>
<TransGear3>1.30</TransGear3>
<TransGear4>1.00</TransGear4>
<FinalGearRatio>3.42</FinalGearRatio>
<DragCoefficient>0.31</DragCoefficient>
<FrontalArea>20.7</FrontalArea>
<TireDiameter>26</TireDiameter>
</CarParameters>
</CarDataset>


Let me know