Super Chevy and DSE Test

[Steve1968LS2]

Understanding why the DSE methodolgy gets markedly faster results than the PHR methodolgy is important, because depending on where and how the measurement variables are introduced, the repeatablity of one of the two methologies may be suspect..

To be clear.. this is not "PHR methodology" it's PRIMEDIA methodology.. same as used with Super Chevy, Chevy High, PHR, Street Rodder, etc...

A set of timing lights is a pretty basic and time tested (pardon the pun) testing method.. lol

[Steve1968LS2]

If DSE were willing to do so, a back-to-back test using the Vbox technology and your fixed, autiomatically triggered timing lights might be a very interesting article.

Yes it would be and Kyle stands by the performance of his system. Maybe we could ship out our lights or they could ship us thier VBOX.

In any case the gain they experienced is still a valid scientificly derived result.. and that's the important part.

[Mkelcy]

Yes it would be and Kyle stands by the performance of his system. Maybe we could ship out our lights or they could ship us thier VBOX.

In any case the gain they experienced is still a valid scientificly derived result.. and that's the important part.

I agree the methodology used by PriMedia is pretty much foolproof. However, unless and until we understand why the DSE methodolgy gets results that are roughly 20% greater than the results the PriMedia methodolgy measures, we can't speak to the validity of the gain measured by DSE.

As for exchanging technologies and running the slalom using both methodologies simultaneously, I'm all for it.

[Damn True]

Oh I get it now. It’s like Einstein relative math. In the car(data acquisition) you are wiggling through cones at 58mph(more distance than 420'/time), but an observer watching from the side (entrance and exit lights) sees a car passing by at 48mph(420'/time). The only thing the same is the time elapsed from the entrance to the exit. Without it, it’s like comparing apples to oranges.

Ding ding ding! Winner. I figured you'd be the first to figure this out.

PHR test - elapsed time from entrance to exit extrapolated into speed
DSE test - speed in MPH while between entrance and exit w/o consideration of time/distance

There is no attempt at funny business or a right or wrong. Just a different way of collecting data. The bummer is that you can't accurately compare the two, because you don't know how far the DSE car deviated from the course centerline, so you can't measure the entire distance covered.

The salient point though is that they picked up 3mph with the modifications. That is HUGE. It by no means though discredits Alcino's time in the PHR test.

[wendell]

not to be a downer but a 3mph increase in 1/4 trap speed would indicate that an 8th spark plug was added in addition to the quadra link rear suspension. While the lower ET may have been a result of the rear suspension, trap speed is a function of horse power and 3mph is a big deal.

[Mkelcy]

Ding ding ding! Winner. I figured you'd be the first to figure this out.

PHR test - elapsed time from entrance to exit extrapolated into speed
DSE test - speed in MPH while between entrance and exit w/o consideration of time/distance

There is no attempt at funny business or a right or wrong. Just a different way of collecting data. The bummer is that you can't accurately compare the two, because you don't know how far the DSE car deviated from the course centerline, so you can't measure the entire distance covered.

The salient point though is that they picked up 3mph with the modifications. That is HUGE. It by no means though discredits Alcino's time in the PHR test.

Assuming you're being serious, no. You are attemtping to measure the average speed at which the car goes through the slalom. In every case, that's a measure of how long (time) the car took to complete the course (distance). How you measure the two variables should NOT affect the result.

[Damn True]

Assuming you're being serious, no. You are attemtping to measure the average speed at which the car goes through the slalom. In every case, that's a measure of how long (time) the car took to complete the course (distance). How you measure the two variables should NOT affect the result.

Except that is not what was done.
PHR uses timing lights. They are capturing the elapsed time from when the car enters the course to when it exits. That time x course distance = speed over the 420' not speed within the course.

DSE used some form of in-car data logger that measured the speed of the car within the course not the speed over the 420'

One is a meausure of speed from a to b, the other is a measure of speed while traveling between a and b. Very different.

[Mkelcy]

Except that is not what was done.
PHR uses timing lights. They are capturing the elapsed time from when the car enters the course to when it exits. That time x course distance = speed over the 420' not speed within the course.

DSE used some form of in-car data logger that measured the speed of the car within the course not the speed over the 420'

One is a meausure of speed from a to b, the other is a measure of speed while traveling between a and b. Very different.

Sorry, the "measure of speed from a to b" and the "measure of speed while traveling between a and b" are both simply time and distance. There is something in the DSE methodology that is giving them very different results from those obtained by the PriMedia methodology. This is not an application of the Heisenberg Uncertainty Principle.

[Damn True]

Sorry, the "measure of speed from a to b" and the "measure of speed while traveling between a and b" are both simply time and distance. There is something in the DSE methodology that is giving them very different results from those obtained by the PriMedia methodology. This is not an application of the Heisenberg Uncertainty Principle.

No, no they are not.
What you are suggesting would only be true if they were capturing the data the same way. They are not.
Think about it.

In the PHR test the actual distance traveled is greater than 420' because of deviation from course centerline. They could, and probably are going just as fast, but the additional distance brings their speed over the 420' course down.

In DSE's test they are measureing the speed within the course irrespective of distance travelled or actual course length.

[wendell]

This whole site just stepped it up a level with a reference to Heisenberg's uncertanty principle. We know how much the camaro weights. We know how fast it was going. If only we could figure out where it is...

[Damn True]

For those who don't know what that is: http://en.wikipedia.org/wiki/Uncertainty_principle

[Mkelcy]

No, no they are not.
What you are suggesting would only be true if they were capturing the data the same way. They are not.
Think about it.

In the PHR test the actual distance traveled is greater than 420' because of deviation from course centerline. They could, and probably are going just as fast, but the additional distance brings their speed over the 420' course down.

In DSE's test they are measureing the speed within the course irrespective of distance travelled or actual course length.

I think you're correct. DSE is apparently using the average speed over a course that is, in effect, substantially longer than 420 feet, while Primedia is assuming a distance of 420 feet regardless how far the car actually travels going between the cones. They're measuring two different things and the results are, as we've seen, very different. Unfortunately, we can't compare the two results because we don't know how far the car in either method actually travelled.

Too bad.

[alcino]

Hallelujah!!! Agreement

[Damn True]

I think you're correct. DSE is apparently using the average speed over a course that is, in effect, substantially longer than 420 feet, while Primedia is assuming a distance of 420 feet regardless how far the car actually travels going between the cones. They're measuring two different things and the results are, as we've seen, very different. Unfortunately, we can't compare the two results because we don't know how far the car in either method actually travelled.

Too bad.

Cool. I thought I was going nuts there for a second.

Irrespective of the difference in data collection the fact that DSE picked up and average of 3mph between their test "A" & "B" is bloody impressive.

[Damn True]

Hallelujah!!! Agreement

More importantly, your record is secure.

[silver69camaro]

What did the Art Morrison 55 chevy do for numbers? Did it have street tires on it?

I would've liked to see the Camaro beat the bigger 55 Chevy, but I can't remember what the number was it was above .9

Art's '55 managed a .94 average and damn close to 49MPH in the cones. This was done on 245/45 and 275/40 BFG KDs. Same tires used to drive from Washington to CA.

I'm pretty excited about the Corvette project with a C5 front and a slightly modified triangulated 4-bar used in the '55. It will be about 800lbs lighter than the '55, with larger tires.

I just wish it would use my 3-link. Either way, I'm sure it will pull some good numbers.

[alcino]

I hate to say record cause I know there are better times out there, for one the morrison gt55 5.92s to my 5.95s slalom. Mine is just currently the best at PHR, and a few other mags. Hope someone beats it on PHR. Maybe then they will let me do some mods and tunning and try to defend my title.(just a ploy to get me in mag again )

[Steve1968LS2]

Ding ding ding! Winner. I figured you'd be the first to figure this out.

PHR test - elapsed time from entrance to exit extrapolated into speed
DSE test - speed in MPH while between entrance and exit w/o consideration of time/distance

There is no attempt at funny business or a right or wrong. Just a different way of collecting data. The bummer is that you can't accurately compare the two, because you don't know how far the DSE car deviated from the course centerline, so you can't measure the entire distance covered.

The salient point though is that they picked up 3mph with the modifications. That is HUGE. It by no means though discredits Alcino's time in the PHR test.

Give this man a cupie doll!

We can't compare the data between the DSE test and say Alcino's car, but we can compare the before and after tests on the DSE car since they were done using the same scientific method.

Case Solved..

[Streetking]

All I can say is, never doubt anything Kyle has to say. He has no reason to b.s. anyone.

For anyone that doesn't believe the numbers, I know they are taking the car to Road Atlanta for more testing, I'm sure he wouldn't mind giving a few rides.

SW

[Damn True]

All I can say is, never doubt anything Kyle has to say. He has no reason to b.s. anyone.

For anyone that doesn't believe the numbers, I know they are taking the car to Road Atlanta for more testing, I'm sure he wouldn't mind giving a few rides.

SW

Nobody is doubting Kyles integrity, the validity of the numbers or the efficacy of the modifications. We are saying that the way he did his test was different, and therefore the results netted a higher speed in both the before and after. The bummer is that because he conducted the test differently we cannot compare those numbers against tests done in a similar fashion to the PHR/Motor Trend test protocol.