[sleepdoc]

Originally Posted by Mr. 5

Another thing to think about is that the trap is not the speed at the end of the 1/4 mile. It's an average speed between 2 points.
The speed you are going at the very end of the 1/4 mile is higher than your trap.

Please explain.

[SteelTorque]

Originally Posted by Mr. 5

Another thing to think about is that the trap is not the speed at the end of the 1/4 mile. It's an average speed between 2 points.
The speed you are going at the very end of the 1/4 mile is higher than your trap.

I think you are wrong there.

[Mr. 5]

Originally Posted by sleepdoc

Please explain.

Originally Posted by SteelTorque

I think you are wrong there.

I was told by a couple draggers that the trap speed is not the speed at which you cross the 1/4 mile. It is an average speed between 2 points, and this makes sense.

In order to determine the speed at the time where you cross the 1/4 means that there is some sort of radar detector. Where is this radar detector.

I could be wrong, but I'll try to dig something up.

[T Bone]

Originally Posted by Mr. 5

He ran a 12.86 at 111.8 mph.
Interesting because I ran 12.38 at 111.8 mph, but I had a 1.8 60 foot.

Looking at just the data..... Digital James would walk you on a roll on the empty roads of Mexico.

Digital James....nice runs...glad to see people just running what they brung....

[Mr. 5]

Originally Posted by Mr. 5

I was told by a couple draggers that the trap speed is not the speed at which you cross the 1/4 mile. It is an average speed between 2 points, and this makes sense.

In order to determine the speed at the time where you cross the 1/4 means that there is some sort of radar detector. Where is this radar detector.

I could be wrong, but I'll try to dig something up.

OK, I was right and I was wrong.
I understand how they do it now.

I was wrong because it pretty much is the fastest speed that you will hit.
It really is the speed at when you break the 1/4 mile.

The way it works:
There are 2 beams close together at the 1/4 mile marker.
The trap is the average speed between these 2 marks.

So, let's say that the first beam is 1 foot before the 1/4 mile.
For me to make a trap of 111.88 mph, I would have had to cross the first beam at 12.374.

111.88 mph = 164 feet/second

164 =aprox (1320-1319)/(12.380-12.374)

Get it?

Originally Posted by T Bone

Looking at just the data..... Digital James would walk you on a roll on the empty roads of Mexico.

Digital James....nice runs...glad to see people just running what they brung....

If it sounded like i was trying to show him up, I wasn't.
I was just saying that it was interesting how we got the same traps.
BTW, how do you know?

[lawdude]

Originally Posted by Mr. 5

I was told by a couple draggers that the trap speed is not the speed at which you cross the 1/4 mile. It is an average speed between 2 points, and this makes sense.

In order to determine the speed at the time where you cross the 1/4 means that there is some sort of radar detector. Where is this radar detector.

I could be wrong, but I'll try to dig something up.

No radar. At end of pass car trips one beam in speed trap and then second beam. Plug numbers into formula r=d/t and voila, trap speed.

[Mr. 5]

Originally Posted by lawdude

No radar. At end of pass car trips one beam in speed trap and then second beam. Plug numbers into formula r=d/t and voila, trap speed.

haha!
beat ya to it. ^^

[lawdude]

Originally Posted by Mr. 5

haha!
beat ya to it. ^^

Haha, yep. Maybe I should before I post.

[turbojet3]

the final beam is beyond the quarter mile finish line.

[T Bone]

Originally Posted by Mr. 5

If it sounded like i was trying to show him up, I wasn't.
I was just saying that it was interesting how we got the same traps.
BTW, how do you know?

No I didn't infer that at all. Just looking at the data.

Digital.James had a much slower 60 foot time that you which means you had much better traction at the start but your car was not able to get beyond 111 mph despite having a quicker start

[Mr. 5]

Originally Posted by turbojet3

the final beam is beyond the quarter mile finish line.

Really?
Are you sure?

This doesn't seem right to me, since the trap should be during the run--not after.

[turbojet3]

no, the first beam is 66 ft before the finish line. the finish is the last beam.

[lawdude]

I think the first beam is 66 feet before finish. I assumed second beam was at finish line.

[lawdude]

Originally Posted by turbojet3

no, the first beam is 66 ft before the finish line. the finish is the last beam.

I thought you said the last beam was beyond the finish line.

<added> Second beam being at the finish line would make sense since 66' = .0125 miles. </added>

[Mr. 5]

Originally Posted by turbojet3

the final beam is beyond the quarter mile finish line.

Originally Posted by turbojet3

no, the first beam is 66 ft before the finish line. the finish is the last beam.

OK, so is the second beam at the finish line or after?
I would think that it would be at the finish line.

And...
If the first beam really is 66 ft before the finish line then I am right!
The speed at the 1/4 is greater than what is displayed on your ticket.

[Sniz]

Originally Posted by Mr. 5

I agree, but if you are one to think about the quicker the 60 foot the lower the trap then then the drag radials won't help with the trap speed.
Everything else that you mentioned makes perfect sense.

that is not always the case. If you are spinning bad in 1st and 2nd gear you are wasting valuable acceleration time/real estate on the 1/4 mile. If you can accelerate at full throttle the entire 1/4 mile, you will have a better trap speed generally.

[hotrod182]

Originally Posted by Sniz

that is not always the case. If you are spinning bad in 1st and 2nd gear you are wasting valuable acceleration time/real estate on the 1/4 mile. If you can accelerate at full throttle the entire 1/4 mile, you will have a better trap speed generally.

I believe the reason why you can often have the better trap with spinning tires at the start is because:

When you are sitting there spinning your tires, you are wasting time not going anywhere, but then you still have all that distance left over to accelerate with your engine closer to its maximum powerband.

When you hook up right away, you vault off the finish line, but you now have less distance left over to accelerate under your maximum power range.

The timing light for the trap speeds isn't influenced by the fact of how long it took you to get through your first 60 ft, whether its 8 seconds, or 1 minute. It just measures how fast you are going at the end of the run.

Also, remember, the highest trap speeds would usually come from Pacific raceway rather than Famosa because of the elevation. 10ft vs 650ft, even if Pacific has a terrible launch pad. On 91 Octane, I run 110mph at sea level with no intercooler or aftermarket intake. Sacramento is another low elevation track. However with its cold temps during Shiv's winter runs, it probably had the best potential for high trap speeds.

[Digital.James]

Originally Posted by hotrod182

On my car, 3rd gear will only take you up to about 100mph, so you need to make the shift to 4th gear. My car runs about 12.83 @ 110.43 on 91 pump gas and 19" and on street tires. With the R switch on and fuel I gain major HP. (113-114mph). But if I could really gain 18hp with an intercooler and intake, that would push my car to about 112mph on pump gas. That wouldn't be bad at all.
By the way, they had a build up of the new Challenger 6.2L Hemi with a Diablo Tune, Borla, and CAI. They said they were "so close" to dipping into the 12's @ 109mph. Let me tell you, how great is it when our cars can run with engines twice the displacement of ours!

That's why Im considering changing to 18s and taller tires. It changes the final gearing of the car and would let me hopefully roll out the quarter in 3rd gear.

Yeah I agree. Our cars have so much potential it's nuts. But people still find tons of reasons to complain.