Autotap Question
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Le Mans Master
Joined: Dec 1999
Posts: 5,169
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From: Greenville SC
Autotap Question
Ok, I was looking at an autotap scan and the columns were grossly misaligned so I loaded it into a spreadsheet to clean it up and study it.
http://temp.corvetteforum.net/c5/vstella//tap6.txt
Anyway, I noticed the time is recorded, in what appears to be ABOUT 0.8 second increments - not real good for measuring e.t.s and such.
But, is that a fixed number - or would the sampling speed increase if you cut down the number of parameters you were logging?
If so, and you could cut enough parameters to get increments of 0.1 seconds or better, then it seems to me the autotap would make for a good e.t. measuring tool and might put to rest some of the questions we have about some of the "hotly debated" mods available.
My thinking would be that if you could get the increment low enough on the autotap, then you could drop it in 4th and measure a pull from 3k to the rev limiter and then do your mod and hop back in and do the same pull.
No shifting involved, and no start line tactics, just a good idea of whether the mod improved HP.
Of course, if 0.8 seconds is the best increment autotap can do, then this is a moot point.
http://temp.corvetteforum.net/c5/vstella//tap6.txt
Anyway, I noticed the time is recorded, in what appears to be ABOUT 0.8 second increments - not real good for measuring e.t.s and such.
But, is that a fixed number - or would the sampling speed increase if you cut down the number of parameters you were logging?
If so, and you could cut enough parameters to get increments of 0.1 seconds or better, then it seems to me the autotap would make for a good e.t. measuring tool and might put to rest some of the questions we have about some of the "hotly debated" mods available.
My thinking would be that if you could get the increment low enough on the autotap, then you could drop it in 4th and measure a pull from 3k to the rev limiter and then do your mod and hop back in and do the same pull.
No shifting involved, and no start line tactics, just a good idea of whether the mod improved HP.
Of course, if 0.8 seconds is the best increment autotap can do, then this is a moot point.
Race Director
Joined: Aug 2000
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From: Cincinnati Ohio
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Re: Autotap Question (Tom Steele)
Can answer your question. Taking it back up. Maybe someone will chime in. Might have better luck asking this in Scan Section :cheers:
Le Mans Master
Joined: Jun 2001
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From: Admit Nothing, Deny Everything, Make Counter Accusations.
Re: Autotap Question (Tom Steele)
Decreasing the number of parameters logged will increase the scan rate, but I do not think that your test will be accurate. The time it takes to log a parameter can vary a little bit even if you do not change anything.
A better idea would be to log MPH and the PCM time parameter and eliminate all of those crazy time stamps in the log. The only way to eliminate the time stamps is to use the DOS version of Autotap. In my experience the DOS version of Autotap logs about twice as fast as the Windows version of Autotap and I think this is partly due to the lack of constant time stamps. I do not know how accurate the PCM time parameter is so this test may never be very accurate.
A better idea would be to log MPH and the PCM time parameter and eliminate all of those crazy time stamps in the log. The only way to eliminate the time stamps is to use the DOS version of Autotap. In my experience the DOS version of Autotap logs about twice as fast as the Windows version of Autotap and I think this is partly due to the lack of constant time stamps. I do not know how accurate the PCM time parameter is so this test may never be very accurate.
Le Mans Master
Joined: Dec 2000
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From: Hot Springs AR
Re: Autotap Question (Tom Steele)
All OBD-II systems can handle approximately 20 data parameter requests per second. However, using that to set up a timeline would, IMO, be greatly inaccurate.
Hope this helps,
Mike
Hope this helps,
Mike
