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Old 06-08-2007, 10:52 PM   #16
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My pan car accelerates about 180 ft in about 1 second reaching 60 mph.
I hope I'm not being dense here, but 180' in 1 second?????

Assuming a constant rate, that's 122 MPH...from a standing start, it would have even a higher terminal speed.

180'/second X 60 = 10,800'/min

10,800/minute X 60 = 648,000'/hr

648,000'/5280 = 122.72 miles/hr

Did I miss something??
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Old 06-08-2007, 10:54 PM   #17
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Nice graph. I like that. I guess my assumption that the cars top out halfway down the straight-away was way off. The cars must be hitting their top speed more like 10-20 feet down the straight then.

Andy
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Old 06-08-2007, 11:08 PM   #18
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Originally Posted by adavid View Post
Nice graph. I like that. I guess my assumption that the cars top out halfway down the straight-away was way off. The cars must be hitting their top speed more like 10-20 feet down the straight then.

Andy
I think this will depend on gearing and type of motor. If you gear to get to top speed by 1/2 way down the straight, you might have slower lap times. It depends on how the infield is setup and what percentage of the total track length the straight comprises. From my graph I am pretty sure I can gear taller and still get more speed, but this is a speed run setup where a 100ft straight would look tiny.

By the way, the scale on the bottom for the time is in 1/10th of a second. This comes from the max data sampling of the eagle tree being 10 Hz (samples per second).
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Old 06-09-2007, 03:06 AM   #19
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Ok, I looked at my eagle tree data and did some work in Excel to find a maximum acceleration of 3.27 G's. I did (V2-V1)/(T2-T1). This was achieved with a TC5 running 6 cells, a non_roar brushless motor and rubber tires. Kind of interesting. According to my data, my max G's was decelerating, -3.47 G's.
If you used only RPM sensor instead of real acceleration sensor your measurements do not consider wheel/road slippage. Therefore real values of car acceleration should be less.
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Old 06-09-2007, 05:36 AM   #20
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Eagle Tree system is a great tool for taking these measurements. I had one a few years ago and measured cornering G, as I recall it was only a little over 1g on a very slippy surface. Unfortunately I no longer have my results.
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Old 06-09-2007, 06:47 AM   #21
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Turbo Joe-my acceleration time was not measured. I do have a video I can get a better measure. Thanks for pointing this out.
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Old 06-09-2007, 07:25 AM   #22
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Hi,
With kufman and sosidge mentioning about the Eagle Tree data recorder and this G-force topic I think this may be interesting to you guys.

I also have the Eagle Tree system and really enjoy using it (hopefully it has made me go a bit faster!!!) but I found the software it comes with is a bit limited to be really useful. Hence people load the data in Excel to graph it, albeit time consuming.
So I wrote my own package which you see in the screen shot:
Theoretical on G force elec on road-race-dae-screen-shot-20060821_3.jpg

I am planning to try to sell a few copies so I would like to know if anyone out there is interested!? If so please contact me! Currently the software only loads the Eagle Tree data but if there are other systems out there that produce a data file I could even improve it to be compatible with alternate formats. I have designed the software to be fast to use, intuitive (as possible) and easy to use, as the last thing you want to do is fight with the software that's supposed to be helping with car setup!

Anyway please tell me what you think?!

Also I have a demo version of my software if you are interested in trying it out please PM me.
The demo version has all the same functionality except you cannot load actual files, it always loads 3 laps of demo data!

Cheers
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Old 06-09-2007, 07:49 AM   #23
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Looks pretty good Cookie, I sent you a PM.
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Old 06-09-2007, 02:02 PM   #24
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That software looks cool.
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Old 06-10-2007, 06:18 AM   #25
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Hi,

Thanks!

Here is a link to the install package for the demo software version:
http://www.cookieitsallgood.com/misc...ackageDEMO.zip

It's about 12.3MB to download.
Unzip to any folder, run the setup.exe and complete the setup wizard to select install location and Start menu entry etc.

Cheers
Andy
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