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If you go down the strip, you will notice that there are two sets of lights and stripes at the finish. The first set is the mph stripe which is approximately 60' before the last stripe which is the finish line. The miles per hour on the time slip is calculated by using the time the car travels over this known distance. Although the car is still accelerating, a 5 mile discrepancy on a 130ish run is too much. If you lift at the mph stripe, there might be a 2 mph difference compared with finishing the run at full throttle. My guess is that the PDR is not accurate or the picture was taken after the 1/4 mile run while the car was increasing in speed.
The video capture was after the finish line for sure. My PDR has never matched the actual time slip from the track. The track timer seems to start after the car actually moves. All comparisons are the same, PDR just a bit behind the track.
Anyhow I am very happy with this time and have all summer to improve.
The PDR (if accurate) will show the actual speed at the end of the quarter. The time slip shows the average speed of the last 60' of a quarter mile run.
Yeah, I know, but do you really think in the course of 120 feet his speed was 5mph different? I sure don't. At the end of the quarter, you're not picking up ONE mph per hundred feet, let alone 5 or 10.
Still something weird!
My overall point is that speed barely changes at the top of the quarter. It changes rapidly at the start but barely at all up top. They should match dead on, really. ET is harder to get right, but speed is easy.
Yeah, I know, but do you really think in the course of 120 feet his speed was 5mph different? I sure don't. At the end of the quarter, you're not picking up ONE mph per hundred feet, let alone 5 or 10.
Still something weird!
My overall point is that speed barely changes at the top of the quarter. It changes rapidly at the start but barely at all up top. They should match dead on, really. ET is harder to get right, but speed is easy.
It's been edited, so no doubt it's correct now :-)
It could be as simple as you say - the pic was taken at a higher speed rather than showing the completion of the quarter as I assumed.
Do you happen to know in the Sportsman classes if they have the traps now BEFORE the finish line? They used to have them 60 before and 60 after but then people weren't lifting right at the line to help with MPH. So they moved it back. But I don't know if that was only the pro classes or if they moved it back for everyone.
It's been edited, so no doubt it's correct now :-)
It could be as simple as you say - the pic was taken at a higher speed rather than showing the completion of the quarter as I assumed.
Do you happen to know in the Sportsman classes if they have the traps now BEFORE the finish line? They used to have them 60 before and 60 after but then people weren't lifting right at the line to help with MPH. So they moved it back. But I don't know if that was only the pro classes or if they moved it back for everyone.
Originally Posted by 383vett
If you go down the strip, you will notice that there are two sets of lights and stripes at the finish. The first set is the mph stripe which is approximately 60' before the last stripe which is the finish line. The miles per hour on the time slip is calculated by using the time the car travels over this known distance. Although the car is still accelerating, a 5 mile discrepancy on a 130ish run is too much. If you lift at the mph stripe, there might be a 2 mph difference compared with finishing the run at full throttle. My guess is that the PDR is not accurate or the picture was taken after the 1/4 mile run while the car was increasing in speed.
I made a mistake when I was cutting and copying my original post. It has been restored in it's entirety. There was nothing to correct. Please read it carefully. The mph light has never been after the finish line in any class.
I made a mistake when I was cutting and copying my original post. It has been restored in it's entirety. There was nothing to correct. Please read it carefully. The mph light has never been after the finish line in any class.
If we're going to play that way, ok. I don't know where the bad attitude came from all of a sudden, but I can adapt. Why so serious?
Your statement is factually and demonstrably incorrect.
The original speed traps were 132' which is 66' on each side of the finish line. That's 1/10th of 1320, by the way. They moved the final beam back to the finish line in 1989. Before that it was, in fact, 66' AFTER the finish line.
Like I said, it was because people weren't lifting right at the finish line in the hopes of improving their MPH, so they "fixed" it. You shouldn't make statements based on the way you -think- things are, you should look it up first.
But if you don't believe me, ask Eddie Hill. He held the world record in Top Fuel so he ought to know. His username is FourFather. Let me know what he says.
Read this article, which conveniently discusses both Eddie and the finish line, then come back:
If we're going to play that way, ok. I don't know where the bad attitude came from all of a sudden, but I can adapt. Why so serious?
Your statement is factually and demonstrably incorrect.
The original speed traps were 132' which is 66' on each side of the finish line. That's 1/10th of 1320, by the way. They moved the final beam back to the finish line in 1989. Before that it was, in fact, 66' AFTER the finish line.
Like I said, it was because people weren't lifting right at the finish line in the hopes of improving their MPH, so they "fixed" it. You shouldn't make statements based on the way you -think- things are, you should look it up first.
But if you don't believe me, ask Eddie Hill. He held the world record in Top Fuel so he ought to know. His username is FourFather. Let me know what he says.
I stand corrected. Not sure where your "bad attitude" claim comes from. By the way, I innocently deleted part of a previous post and you accused me of editing and correcting the post which I did not.
05-12-2018, 03:44 PM
Well done.
