Simply question about the traps
Originally Posted by 94z28L
believe different track have different lengths and systems, but like you said its as simple as velocity=(time)/(distance)
What I am asking is this: How many feet at the end of the 1320 is used to determine the trap speed?
Trap Speed is measured during the last 60 feet of the 1/4-mile.
More info can be found here: http://www.staginglight.com/guide/defns.html
More info can be found here: http://www.staginglight.com/guide/defns.html
Staging Lane
Joined: Apr 2005
Posts: 92
Likes: 0
From: Westminster, MD
For some reason, I remember mph being calculated based upon 66' before the finish line. Not too many years ago, mph was calculated from two points, one 66' before the finish line and another 66' after the finish line. problem was many racers would hold the thottle through to the last mph photocell to get more mph on their time slip. On tracks with marginal length finish lines, that could be considered a safety issue. Due to this, NHRA eliminated the second mph photocell.
I think there really can be measurable differences in time slips between tracks. Only thing I can figure is minute differences in photo cell placement, be it distance (length) from each other, or even possibly the height at which they are mounted, or even the amount of crown the track surface has which affects the height and rollout. I'm refering to all photocells, not just staging beams. We have two tracks I run at and on is at 525' elevation, the other 325' elevation. The first is a good tenth to .15 in ET slower as well as 2 mph slower than the second. Just 200' in elevation will not creat such a great difference in ET & mph. Really makes you scratch your head to the exact cause to the ET & mph difference.
I think there really can be measurable differences in time slips between tracks. Only thing I can figure is minute differences in photo cell placement, be it distance (length) from each other, or even possibly the height at which they are mounted, or even the amount of crown the track surface has which affects the height and rollout. I'm refering to all photocells, not just staging beams. We have two tracks I run at and on is at 525' elevation, the other 325' elevation. The first is a good tenth to .15 in ET slower as well as 2 mph slower than the second. Just 200' in elevation will not creat such a great difference in ET & mph. Really makes you scratch your head to the exact cause to the ET & mph difference.
Originally Posted by BriancWS6
There shouldn't be any differences between different tracks. If there was there would be huge contraversary about trap speeds, etc on this board when people post up their results.
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6 & 8 Second Club
Joined: Aug 2006
Posts: 2,284
Likes: 0
From: Illinois, RT 66 dragway area
Originally Posted by DOTracer
For some reason, I remember mph being calculated based upon 66' before the finish line. Not too many years ago, mph was calculated from two points, one 66' before the finish line and another 66' after the finish line. problem was many racers would hold the thottle through to the last mph photocell to get more mph on their time slip. On tracks with marginal length finish lines, that could be considered a safety issue. Due to this, NHRA eliminated the second mph photocell.
I think there really can be measurable differences in time slips between tracks. Only thing I can figure is minute differences in photo cell placement, be it distance (length) from each other, or even possibly the height at which they are mounted, or even the amount of crown the track surface has which affects the height and rollout. I'm refering to all photocells, not just staging beams. We have two tracks I run at and on is at 525' elevation, the other 325' elevation. The first is a good tenth to .15 in ET slower as well as 2 mph slower than the second. Just 200' in elevation will not creat such a great difference in ET & mph. Really makes you scratch your head to the exact cause to the ET & mph difference.
I think there really can be measurable differences in time slips between tracks. Only thing I can figure is minute differences in photo cell placement, be it distance (length) from each other, or even possibly the height at which they are mounted, or even the amount of crown the track surface has which affects the height and rollout. I'm refering to all photocells, not just staging beams. We have two tracks I run at and on is at 525' elevation, the other 325' elevation. The first is a good tenth to .15 in ET slower as well as 2 mph slower than the second. Just 200' in elevation will not creat such a great difference in ET & mph. Really makes you scratch your head to the exact cause to the ET & mph difference.
You are correct on both issues. There are always little things about every track, and people were bitching about burning up their cars the last 66' just for a better MPH, the race was already over.
The little crappy track near me has always had short 60' lights. If you get a good launch, the 60' will be a tiny bit better than other places, but the ET is the exact same per weather. We know for a fact the track is not hooking better than other tracks, because we have to soften the launch 75% of the time. So obviously it's in the equipment, if dozens of people get the same results.
I also read an article, where a guy secretly measured a bunch of tracks, and found a bunch of old tracks were short, 10, 30, 50 feet. He said most new track were good. He also claimed on one track, the elect system was so old, that when the food trailer was cooking something, the ET would be slower from the power drain. Slowing the clocks down????
Be safe everyone.
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TECH Enthusiast
Joined: Sep 2003
Posts: 503
Likes: 1
From: Texas
Originally Posted by kp
Well unfortunately thats not the case, there is a variation between equipment manufactures, a few feet here or there, beam height, temp affects the timers (crystal time based) and you are talking about thousanths of a second with miles of wires, lights that get ran over many times etc etc. Trust me the timeslip racers know the places to go (and even which lanes are better at some tracks) but drag 'racing' is a sport, whoever cuts the better light and crosses the finsh line first wins - not who has the best timeslip
When we first started using data management, logging engine RPM vs drive line RPM and plotting events at various track locations, that sort of stuff drove us nuts!...especially when some of the tracks started looking to be 20 to 100 foot short!!
Originally Posted by kp
Well unfortunately thats not the case, there is a variation between equipment manufactures, a few feet here or there, beam height, temp affects the timers (crystal time based) and you are talking about thousanths of a second with miles of wires, lights that get ran over many times etc etc. Trust me the timeslip racers know the places to go (and even which lanes are better at some tracks) but drag 'racing' is a sport, whoever cuts the better light and crosses the finsh line first wins - not who has the best timeslip
Thanks for all the replies guys, good info in here.
Originally Posted by BriancWS6
Oh I definately understand that aspect. I meant that there wouldn't be X track using 60ft for the traps and Y track using 75ft for traps.
Thanks for all the replies guys, good info in here.
Thanks for all the replies guys, good info in here.
For some reason the 66' thing sticks in my head but different timing systems may use a slightly different length traps for mph.