Congrats JR Todd, but your front wing is still flopping! (1 Viewer)

UHHHH....Flippy-floppy equals a portion of the front of the car dropping below the 3 inch minimum ground clearance in the lights...:rolleyes:

I hate to say it, because I would love to see JR and Evan kick butt this year, but has anyone super slo-mo'ed the flippy-floppy action when he's entering the traps? If the wing starts off at 3" high at staging, is all that movement at speed tripping the beams :( ?

The finish line and down track beams are approx 6" off the ground.
 
No its been that way for a LOOOONG time. even the 70s when snow shovels started appearing on the torsion bar front suspensions of Dragsters. It has always been a factor. the et stop and mph beams are higher off the track surface than the start beams which are very close to the surface. next time at the track notice the position of the reflectors on the foam cubes on the centerlines. They are right in the middle. and the blocks are about 10 or 12 inches square.

I will add this bit of trivia also
The MPH start and stop beams used to straddle the finish line. The MPH et start was 33 feet before the finish line the mph ET stop USED to be 33 feet beyond the finish line. Some competitors would "'Run it out the back door" (IE "Back door Bob Strucksness') In an attempt to capture top MPH. I forget what year it was but (early 80s?) When speeds and short tracks started to become a problem the speed et stop trap was moved to before the finish line. So today In Theory. the MPH at the finish line is actually faster than what is being timed or reported. It is only the average speed calculated by the elapsed time measured in a segment of track preceding the finish line.

Al, are sure about that mph claim, regarding the relocated traps? Not trying to dispute your contention, but I seem to view this another way.

In the old days, as you mentioned, the last speed trap light was past the finish line. If a car ran "out the back door" (loved that Struksnes reference!) it would be accelerating past the finish line, and the speed reported for the run would be faster than that actually attained at the finish line.

When the speed traps no longer straddled the finish line, there was no need to run past the finish for top speed points, etc. The speed recorded for the run would be the actual speed attained at the finish line, for all practical purposes. The car wouldn't be accellerating for that additional track past the line.

This had a net effect of "slowing down the cars", consistant with NHRA's (and the damn insurance companies...) desires back then.

If ya remember, the 300mph mark was deemed absolutely taboo at that time.

Regards
 
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No its been that way for a LOOOONG time. even the 70s when snow shovels started appearing on the torsion bar front suspensions of Dragsters. It has always been a factor. the et stop and mph beams are higher off the track surface than the start beams which are very close to the surface. next time at the track notice the position of the reflectors on the foam cubes on the centerlines. They are right in the middle. and the blocks are about 10 or 12 inches square.

I will add this bit of trivia also
The MPH start and stop beams used to straddle the finish line. The MPH et start was 33 feet before the finish line the mph ET stop USED to be 33 feet beyond the finish line. Some competitors would "'Run it out the back door" (IE "Back door Bob Strucksness') In an attempt to capture top MPH. I forget what year it was but (early 80s?) When speeds and short tracks started to become a problem the speed et stop trap was moved to before the finish line. So today In Theory. the MPH at the finish line is actually faster than what is being timed or reported. It is only the average speed calculated by the elapsed time measured in a segment of track preceding the finish line.

66 ft before and 66ft after= 132 ft or 1/10 of a 1320... and runnin' it out the backdoor meant something when points were given for the speed record also
 
66 ft before and 66ft after= 132 ft or 1/10 of a 1320... and runnin' it out the backdoor meant something when points were given for the speed record also

You are correct Karl, it was 66 feet not 33 as i mentioned. Its been awhile. gettin old.


Al, are sure about that mph claim, regarding the relocated traps? Not trying to dispute your contention, but I seem to view this another way.

In the old days, as you mentioned, the last speed trap light was past the finish line. If a car ran "out the back door" (loved that Struksnes reference!) it would be accelerating past the finish line, and the speed reported for the run would be faster than that actually attained at the finish line.

When the speed traps no longer straddled the finish line, there was no need to run past the finish for top speed points, etc. The speed recorded for the run would be the actual speed attained at the finish line, for all practical purposes. The car wouldn't be accelerating for that additional track past the line.

This had a net effect of "slowing down the cars", consistant with NHRA's (and the damn insurance companies...) desires back then.

If ya remember, the 300mph mark was deemed absolutely taboo at that time.

Regards

Steve
because todays speeds are measured in a segment before the finish line there is no way to measure the actual speed At the finish line.. The closest you can get is an average of speed within the segment. Which would theoretically be at a point 33 feet before the finish line in a 66 foot trap. the car is(should without limiters) still accelerating the final 33 feet so the speed at the finish line should be faster than posted.. I think you are assuming I meant the speed trap was only after the finish line. Only half of it was. the first half was before the finish line the second half after the finish line for a theoretical average which would place the true MPH at the finish line.
 
The finish line and down track beams are approx 6" off the ground.
Actually, they are supposed to be 5" off the ground.

The starting line beams are approximately 1-1/2" to 1-3/4" off the ground depending on the actual distance between the beams in order to get the proper rollout.
 
You are correct Karl, it was 66 feet not 33 as i mentioned. Its been awhile. gettin old.




Steve
because todays speeds are measured in a segment before the finish line there is no way to measure the actual speed At the finish line.. The closest you can get is an average of speed within the segment. Which would theoretically be at a point 33 feet before the finish line in a 66 foot trap. the car is(should without limiters) still accelerating the final 33 feet so the speed at the finish line should be faster than posted.. I think you are assuming I meant the speed trap was only after the finish line. Only half of it was. the first half was before the finish line the second half after the finish line for a theoretical average which would place the true MPH at the finish line.

Al,

This stuff can get kind of confusing, huh?! :rolleyes:

Actually, I agree that one cannot measure the speed at any one particular point on the track, as you point out. The speed is is mathematically calculated using the time/distance equation, and the average speed over said distance is the result of this equation.

Lets assume a car accelerates to the last speed trap, whether at the finish line, as is now the case, or 66 ft past using the old method. Also lets assume the car has an identical et, since the actual finish line is 1/4 mile in both instances.

By definition, a continually accelerating car would be traveling faster the further down track it goes. If one uses the old method (speed traps straddle the finish line) the car would be traveling through the speed traps in a shorter time, as the car would still be accelerating for an additional 66 ft. past the finish line. And the corrosponding speed readout would be higher.

Using the method currently in place, the cars' speed timing would stop at the finish line, which is 66 ft. further uptrack from the old method. Hence the car wouldn't have as much time to accelerate down track and the speed would be measured as slower. We may be talking only a couple of hundreths difference here between the two methods, but there would be a time/speed difference. Old way = faster speed readout, new way = slower speed readout.

Now, of course, I could be wrong. My wife is always telling that very thing!

BTW, don't feel too bad about getting old. It's happening to me also! :)

Nonetheless, it does makes for an interesting discussion. And also illustrates one of many reasons why it can be difficult to explain drag racing to newbies.

Steve
 
Actually, they are supposed to be 5" off the ground.

The starting line beams are approximately 1-1/2" to 1-3/4" off the ground depending on the actual distance between the beams in order to get the proper rollout.

I thought it was around 6", I just wasn't sure of the specified/mandated height.
 
No its been that way for a LOOOONG time. even the 70s when snow shovels started appearing on the torsion bar front suspensions of Dragsters. It has always been a factor. the et stop and mph beams are higher off the track surface than the start beams which are very close to the surface. next time at the track notice the position of the reflectors on the foam cubes on the centerlines. They are right in the middle. and the blocks are about 10 or 12 inches square.

I will add this bit of trivia also
The MPH start and stop beams used to straddle the finish line. The MPH et start was 33 feet before the finish line the mph ET stop USED to be 33 feet beyond the finish line. Some competitors would "'Run it out the back door" (IE "Back door Bob Strucksness') In an attempt to capture top MPH. I forget what year it was but (early 80s?) When speeds and short tracks started to become a problem the speed et stop trap was moved to before the finish line. So today In Theory. the MPH at the finish line is actually faster than what is being timed or reported. It is only the average speed calculated by the elapsed time measured in a segment of track preceding the finish line.

Al,

I went back and reread your original post and ya know what? I did misread it! You are absolutey correct. Actually we were both correct, we were just debating two different things.

Sorry Al.

I sure hope you guys don't want to ban me! :D
 
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