No Fly Arizona Dec 12/13
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Joined: Apr 2011
Posts: 256
From: nj
Rep Power: 85
I see. Ignore the 184. I had a bunch of slips on the table and that got caught in the picture. I had 9 of them laid out by fastest time I did that day. The 188 is the only relevant one in this topic.
1/2 mile run with vbox data was the same run that I did 188 on trap, add in the ~300 feet go give you the difference of 8mph between the 1/2 mile of 180.4(6) and the 188.1 speed on the slip - 3000-2640 = 360ft, which was the added distance to give me the slip vs vbox data.
Now, if I started my car at the cones and logged that time, you would see the true variance in the timers versus the speed/vbox. However, I don't recall anyone using those trap timers for true speed calculation, most people used a vbox.
What I am saying is my vbox showed 188 mph where i crossed the lap trap timer and my slip showed the same time; therefore, in my case, the track timer was accurate to speed according to what my vbox reflected. The only variance to calculate here would be if I continued to accelerate after the cones (i.e. how quickly did I get my foot off the pedal after passing them). Which means that my Vmax would show 188, but my official crossing time would have been 186.x. If the timers were reading high, then I wouldn't have known unless I checked all slips versus data.
Does that help clarify?
1/2 mile run with vbox data was the same run that I did 188 on trap, add in the ~300 feet go give you the difference of 8mph between the 1/2 mile of 180.4(6) and the 188.1 speed on the slip - 3000-2640 = 360ft, which was the added distance to give me the slip vs vbox data.
Now, if I started my car at the cones and logged that time, you would see the true variance in the timers versus the speed/vbox. However, I don't recall anyone using those trap timers for true speed calculation, most people used a vbox.
What I am saying is my vbox showed 188 mph where i crossed the lap trap timer and my slip showed the same time; therefore, in my case, the track timer was accurate to speed according to what my vbox reflected. The only variance to calculate here would be if I continued to accelerate after the cones (i.e. how quickly did I get my foot off the pedal after passing them). Which means that my Vmax would show 188, but my official crossing time would have been 186.x. If the timers were reading high, then I wouldn't have known unless I checked all slips versus data.
Does that help clarify?
They are all relevent
But thats not how anything actually plays out. The sensors measure the average time over distance. What I tell all our racers in the meeting is to visualize that the front wheels start the race ( we have start mph) and your REAR wheels end the race, so continue accelerating PAST the cones/flags (sensors) to get your most accurate mph.
This is what it shows you have done. Your log shows going past 3k feet for that vmax of 188, so vmax @188@32xxft. but yet your mph slip shows 188.
Without seeing the full logs in the other graph form, we cant see what that ~200ft is worth in terms of mph.
So im still rather convinced there was a slight error.
Your car is blazing fast, no denying that. 18x is a fast car. I didnt mean stir drama, and gladly it doesnt seem like people, or yourself took it that way. Its just I have a passion for following this sort of thing and the accuracy of these events so we can all share our data globally for accurate comparisons, like 60-130's
No drama, I am just trying to state that the time is accurate based on the vbox data.
The length of the track does not matter as the vbox is doing all of that for you via GPS data.
Since we're debating the accuracy of the timers, then yes, there could be variance. However, when I ran that 188.x I used the full length of the track, which is the rolling area, which we've determined is a minimum of 300ft, likely between 300-400ft, but probably not greater than 450ft.
I reached 188.1x @ 3043 feet. Which I started from a dig at the very back end of the track to include that rolling start area.
To get a little more precise: 3043-2640=403ft of "rolling start" area. Assuming I started decel at the instant I hit the cones/timer.
The trap timer gave me the same speed as my vbox.
Now, if we knew the exact distance, measured, of the rolling area; let's say it was 300ft exactly. That would mean I have an extra 103ft of potential speed after the timer which would equate to a higher vmax speed.
Doing the math, if I was traveling at 186mph at crossing, that's 272.8 feet per second. If that were the case, my extra distance in vmax would only equate to 0.378 seconds in speed. If my math serves me correctly.
If I kept my foot in it too long, let's call it 2 seconds after passing the cones, I'd have traveled over 500ft. 2 seconds is a pretty damn slow reaction time for decel. I figure anything under 2/3 of a second is reasonable.
Since I'm fairly certain that the rolling area was no less than 300ft
All in all, the trap timer has no relevance when comparing it to a vbox. You can see if they're both reading similarly, but I'd take vbox data over the rig they were using. Now if this were something official, one could argue the other way. But nobody was there to get actual record times.
The length of the track does not matter as the vbox is doing all of that for you via GPS data.
Since we're debating the accuracy of the timers, then yes, there could be variance. However, when I ran that 188.x I used the full length of the track, which is the rolling area, which we've determined is a minimum of 300ft, likely between 300-400ft, but probably not greater than 450ft.
I reached 188.1x @ 3043 feet. Which I started from a dig at the very back end of the track to include that rolling start area.
To get a little more precise: 3043-2640=403ft of "rolling start" area. Assuming I started decel at the instant I hit the cones/timer.
The trap timer gave me the same speed as my vbox.
Now, if we knew the exact distance, measured, of the rolling area; let's say it was 300ft exactly. That would mean I have an extra 103ft of potential speed after the timer which would equate to a higher vmax speed.
Doing the math, if I was traveling at 186mph at crossing, that's 272.8 feet per second. If that were the case, my extra distance in vmax would only equate to 0.378 seconds in speed. If my math serves me correctly.
If I kept my foot in it too long, let's call it 2 seconds after passing the cones, I'd have traveled over 500ft. 2 seconds is a pretty damn slow reaction time for decel. I figure anything under 2/3 of a second is reasonable.
Since I'm fairly certain that the rolling area was no less than 300ft
All in all, the trap timer has no relevance when comparing it to a vbox. You can see if they're both reading similarly, but I'd take vbox data over the rig they were using. Now if this were something official, one could argue the other way. But nobody was there to get actual record times.
Last edited by dhahlen; Dec 15, 2015 at 03:05 PM.
Registered User
Joined: Apr 2011
Posts: 256
From: nj
Rep Power: 85
No drama, I am just trying to state that the time is accurate based on the vbox data.
The length of the track does not matter as the vbox is doing all of that for you via GPS data.
Since we're debating the accuracy of the timers, then yes, there could be variance. However, when I ran that 188.x I used the full length of the track, which is the rolling area, which we've determined is a minimum of 300ft, likely between 300-400ft, but probably not greater than 450ft.
I reached 188.1x @ 3043 feet. Which I started from a dig at the very back end of the track to include that rolling start area.
To get a little more precise: 3043-2640=403ft of "rolling start" area. Assuming I started decel at the instant I hit the cones/timer.
The trap timer gave me the same speed as my vbox.
Now, if we knew the exact distance, measured, of the rolling area; let's say it was 300ft exactly. That would mean I have an extra 103ft of potential speed after the timer which would equate to a higher vmax speed.
Doing the math, if I was traveling at 186mph at crossing, that's 272.8 feet per second. If that were the case, my extra distance in vmax would only equate to 0.378 seconds in speed. If my math serves me correctly.
If I kept my foot in it too long, let's call it 2 seconds after passing the cones, I'd have traveled over 500ft. 2 seconds is a pretty damn slow reaction time for decel. I figure anything under 2/3 of a second is reasonable.
Since I'm fairly certain that the rolling area was no less than 300ft
All in all, the trap timer has no relevance when comparing it to a vbox. You can see if they're both reading similarly, but I'd take vbox data over the rig they were using. Now if this were something official, one could argue the other way. But nobody was there to get actual record times.
The length of the track does not matter as the vbox is doing all of that for you via GPS data.
Since we're debating the accuracy of the timers, then yes, there could be variance. However, when I ran that 188.x I used the full length of the track, which is the rolling area, which we've determined is a minimum of 300ft, likely between 300-400ft, but probably not greater than 450ft.
I reached 188.1x @ 3043 feet. Which I started from a dig at the very back end of the track to include that rolling start area.
To get a little more precise: 3043-2640=403ft of "rolling start" area. Assuming I started decel at the instant I hit the cones/timer.
The trap timer gave me the same speed as my vbox.
Now, if we knew the exact distance, measured, of the rolling area; let's say it was 300ft exactly. That would mean I have an extra 103ft of potential speed after the timer which would equate to a higher vmax speed.
Doing the math, if I was traveling at 186mph at crossing, that's 272.8 feet per second. If that were the case, my extra distance in vmax would only equate to 0.378 seconds in speed. If my math serves me correctly.
If I kept my foot in it too long, let's call it 2 seconds after passing the cones, I'd have traveled over 500ft. 2 seconds is a pretty damn slow reaction time for decel. I figure anything under 2/3 of a second is reasonable.
Since I'm fairly certain that the rolling area was no less than 300ft
All in all, the trap timer has no relevance when comparing it to a vbox. You can see if they're both reading similarly, but I'd take vbox data over the rig they were using. Now if this were something official, one could argue the other way. But nobody was there to get actual record times.
Video at the bottom of my first post versus a GTR.
Of this particular run... with 188mph.. here:
https://www.facebook.com/pobudz/videos/10207687885828155/
Registered User
Joined: Apr 2011
Posts: 256
From: nj
Rep Power: 85
https://www.6speedonline.com/forums/...w-results.html
Video at the bottom of my first post versus a GTR.
Of this particular run... with 188mph.. here:
https://www.facebook.com/pobudz/vide...7687885828155/
Video at the bottom of my first post versus a GTR.
Of this particular run... with 188mph.. here:
https://www.facebook.com/pobudz/vide...7687885828155/
I've got the mapping down and all the distances, I dont post the images in public as its bad form, but it still doesnt correlate to the numbers. If you want to look further into it in private i can email you
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