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Discussion Starter · #1 · (Edited)
First, a big thanks to Scott (Racemx-m3) and Chris (HPF Chris) for providing ample data for me to use to test and refine this spreadsheet. I couldn't have done it without them...


Part 1 was mostly proving that the theory would translate into practice, and I had a couple people ask for the spreadsheet so they could use on their own. Now that I'm confident in the various corrections, I have tried to make the spreadsheet as user friendly as possible. You can download it here: http://www.mediafire.com/file/nnhyjn22okk/PBOXdyno.ods

If you don't recognize the ".ods" format, it is open office calc (available for free: http://www.openoffice.org/ ). Many of you have excel, but some don't so this seemed to be the easiest way.

Update: Here is a MS works version (you should be able to open it with excel): http://www.mediafire.com/file/oyniyymy5tz/PBOXdyno.xlr


When you open it up, it should look like this (sorry in advance if screen shots are too big for some monitors):



You will only need to enter data into the red boxes (green box is optional if you want to graph rpm instead of speed). Don't touch anything else unless you know what you're doing...


Now open up the Vbox software and load your run. I'm using the driftbox tools software so it may be a little different.

Here I'll be demonstrating with a pump gas run for a HPF stage 1 car (actually stage 2 -- but without meth):




Under the "graph data" window, make sure Speed (mph), Height (feet), and Distance (feet) are checked (and nothing else). If the units are not in mph/feet, you can change the settings under "options" --> "units of measurement."




Now move the cursor to the start of the run, click "edit data" and "cut all data before cursor" (you can also hotkey shift-x):




Now move the cursor to the end of the run, click "edit data" and "cut all data after cursor" (or hit ctrl-x):




Now click "export" --> "chart" and a TeeExportForm dialogue box pops up. Click the "Data" tab, and make sure format is "text" and delimiter is "tab"




Click save, pick whatever name you want -- just make sure you know where it saved to (I prefer the desktop). Now open that file in notepad/wordpad, hit ctrl+a (selects all) and ctrl+c (copies):




Then go back to the open office calc spreadsheet, click on cell A2, and hit ctrl+v (pastes). A pop-up window will appear -- just hit OK:




Most of the spreadsheet should now automatically fill. Now look at the other red box and make sure the values are correct for your car & the weather at the time of your run. The e46 M3 has a Cd of .32, the frontal area is somewhere in the 22-24' area (this one isn't too critical), weight is 3500-3600lbs + turbo kit + driver. For the weather I go to wunderground.com -- type in "Portland, OR" scroll down to "history & almanac" and put in 11/29/09 (when I believe Chris made this run). At 3:53 that afternoon, I get:




From the vbox data, I see Chris was running on a 30-33* heading (NNE) so the 6mph WNW wind was pretty much at his side. You can leave headwind as zero, or do 1/2 of the wind (since x-winds do add drag). 2.6mph is nothing, but I'll put it in anyway. Pressure was 30.33, temp 43, and humidity 74% For the Green box, these gear multipliers are about right for e46 M3 stock gearing and typical slightly larger (diameter) rear tires although feel free to adjust them to your specs:




If this run had been done over multiple gears, I'd probably just plot speed vs rwhp. To do this, just highlight cells AA9 - AD9 and scroll down until you get "#DIV/0!" -- then click insert chart (and follow the steps under "graphing" below).


But since this run was all done in 4th gear, we can easily get rpm (and from rpm & HP -- we can get torque). So scroll over to AF10, highlight the cell, type in "=$I$14*B10" -- then hit enter. Click back on AF10, right click copy, then click AF11 and drag down as far as AG has valid data (in this case AF 167). Right click again, and select paste. This section of the spreadsheet should now be filled in (the torque values specifically).
 

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Discussion Starter · #2 · (Edited)
Graphing:

highlight all of the cells (including the first row with the titles) you want to graph, click Insert --> chart. A graph appears with a chart wizard. Select "XY (Scatter)" and "lines only"




Click next, make sure "data series in columns" and "first row as label" are checked, then click next again. Step 3 -- just click next again. Step 4, chart elements. You can add a title ("Terry HPF M3"), subtitle (Pump Gas (no meth)), X-axis title: RPM, Y-axis title: RWHP/RWTQ. I generally like the legend on the left, and I like to check display grids for X and Y axis:




You're pretty much done unless you want to spend a little time expanding the graph, changing the scale of the axis, changing the color and thickness of the lines, etc. Here's what I come up with:




I've done some techniques to help with smoothing, but keep in mind the data is taken every 0.1 second (whereas a dyno probably samples 10x as fast) so there are going to be some bumps and dips that probably aren't really there. This graph also happened to be one of the most jagged -- most should be better. Anyway, the general trends should be very accurate (and, as many outside the US have long known, in most cases will be lower than "dynojet" figures)


Other notes: I added SAE and STD correction factors. I'm not really a fan of using correction for FI vehicles (especially turbo), but everyone seems to want SAE. Keep in mind the "actual" numbers are what the car truly made that day -- SAE/STD are basically an educated guess as to what they would make under those preset atmospheric conditions.



other graphs:

Terry pump+meth:



Terry Race (no meth):



Terry Race+meth:



Scott's 4th gear pull last year:



Compare the above with the dynojet runs, and you'll typically see +100ftlbs ~4000rpm (from turbo being able to spool much faster on the road), but also 20-40hp less peak hp...



Scott's recent 5.83 60-130 run on the new HPF stage 2.5 tune:



Scott's friend (TT viper -- estimated weight 3650, estimated temp 60* estimated pressure 30.3)
 

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Can you set us up with your version of Performance Box software i see you got, "Beta release - Developers department"?
I've tried that feature where you export to text and i get an error memory access every single time. I've tried this on two different computers i assume it's a glitch within performance box.

I can export it to the other formats like excel though. But performance box does not like to export to text.
 

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http://www.driftbox.com/download/DriftBoxToolsBeta.zip

If you can export it to excel, you should also be able to just copy/paste the data. I'll also try and get an MSworks version (I don't have excel on this computer, but excel can open MSworks files)...
Thanks this version works.

I tried a few vehicles one a stock suv which has 300bhp from the factory i believe this software stated it had 250rwhp. which is about right.

I tried 2 other cars which had dyno's that week. They came out a little short of power on this program versus what the dyno stated. I will have to fool around with it a bit more.
 

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Discussion Starter · #13 ·
I tried a few vehicles one a stock suv which has 300bhp from the factory i believe this software stated it had 250rwhp. which is about right.

I tried 2 other cars which had dyno's that week. They came out a little short of power on this program versus what the dyno stated. I will have to fool around with it a bit more.
What kind of dyno did they run on, and what percent off is it? Is the overall shape of the power curve the same?
 

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Can you run one for my vbox time? Does you take g's, traction and letting on/off throttle into consideration at all?
 

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Discussion Starter · #16 ·
Can you run one for my vbox time? Does you take g's, traction and letting on/off throttle into consideration at all?
Yours didn't come out too well -- looks like you had quite a bit of tire spin at 6000 and a little more at 7000rpm...


(ignore the 3rd/4th stuff, that was left over from a previous graph)
 

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Yours didn't come out too well -- looks like you had quite a bit of tire spin at 6000 and a little more at 7000rpm...


(ignore the 3rd/4th stuff, that was left over from a previous graph)
Geez man thats crazy! I was expecting more power, in the vbox graph it shows .6, .7+ acceleration G's at times. Cant believe i ran a 6.8 with that condition...
 

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Discussion Starter · #18 · (Edited)
Geez man thats crazy! I was expecting more power, in the vbox graph it shows .6, .7+ acceleration G's at times. Cant believe i ran a 6.8 with that condition...

I had your car weighing 3500lbs with driver (I remember it being semi-gutted). If it was 3800lbs with driver, you'd be at >680rwhp:


The other thing to consider is that the power this calculates seems comparable to dyno dynamics so add ~7% for "dynojet" numbers.
 

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Psshhhht M3
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I had your car weighing 3500lbs with driver (I remember it being semi-gutted). If it was 3800lbs with driver, you'd be at >680rwhp:


The other thing to consider is that the power this calculates seems comparable to dyno dynamics so add ~7% for "dynojet" numbers.
I would say at the time of the run the car should have weighed around 3500, so youre pretty much accurate.
 
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