I will be heading to the track this weekend and the weather is questionable friday night so I will try to put some graphs from racepak together to illustrate what I am saying.

I believe Lenny, with the relay I would still need the trans drop 12v signal to achieve all the information needed. If racepak allowed 2 12 v recorded signals - then I could do what your saying. Only 1 event can be recorded.

What I am hearing from most of the people here is they are doing the same as me. Basically not touching the box unless its some major assignable cause (like the sunlight). Doesn't sound like many - if they are low teens - trust pulling .005 out and having it be high .00X....

quote:

Originally posted by ski_dwn_it:
I believe Lenny, with the relay I would still need the trans drop 12v signal to achieve all the information needed. If racepak allowed 2 12 v recorded signals - then I could do what your saying. Only 1 event can be recorded.

That's what the Normally Closed relay is for. When you press the transbrake button, it would Open the circuit and the logger would not record voltage. Once you release the button, the relay would Close and you should see voltage recorded for the duration of the Delay.

quote:

Originally posted by Lenny5160:

quote:

Originally posted by ski_dwn_it:
There is only 1 12v event recorded so you see when I push the button 12v active, but I might be on it for different intervals and then you see it drop. There is no release of button shown, only when box releases 12v signal.

From the release you can measure the "dead time" I would think to when it cracks the tire. I usually start log at point of trans release to get graphs to overlay and they do perfectly. In other words the crack of the tire aligns which tells me at least that portion is very very consistent. That would be the dead time.

Once the car starts moving till it leaves the beams nobody can tell, even with the device listed above. You can assume its moving the same but its just a calculation off likely the Gforces starting to ramp. To truely know you would need something measuring distance to track and/or distance traveled. Likely laser devices like found on cars to prevent them from wheelstanding. Both of which would not be viewed as legal in the eyes of some or many.

You could put a Normally Closed relay in the wire that sends the Transbrake signal to the Racepak. This relay would be activated by the button itself, so the Racepak will only see voltage after button release.

Make this simple. Add a wire to Trigger 1 terminal on the K&R and land the other end to a Racepak 12v input. Measure the time from when that Terminal 1 input goes low (0v) to when the delay box releases (0v) the +12v to the transbrake. This should correspond to the delay time in the K&R.

You are looking for this value to repeat as it will likely be off slightly from the actual delay setting.

quote:

Originally posted by markemark:

quote:

Originally posted by Lenny5160:

quote:

Originally posted by ski_dwn_it:
There is only 1 12v event recorded so you see when I push the button 12v active, but I might be on it for different intervals and then you see it drop. There is no release of button shown, only when box releases 12v signal.

From the release you can measure the "dead time" I would think to when it cracks the tire. I usually start log at point of trans release to get graphs to overlay and they do perfectly. In other words the crack of the tire aligns which tells me at least that portion is very very consistent. That would be the dead time.

Once the car starts moving till it leaves the beams nobody can tell, even with the device listed above. You can assume its moving the same but its just a calculation off likely the Gforces starting to ramp. To truely know you would need something measuring distance to track and/or distance traveled. Likely laser devices like found on cars to prevent them from wheelstanding. Both of which would not be viewed as legal in the eyes of some or many.

You could put a Normally Closed relay in the wire that sends the Transbrake signal to the Racepak. This relay would be activated by the button itself, so the Racepak will only see voltage after button release.

Make this simple. Add a wire to Trigger 1 terminal on the K&R and land the other end to a Racepak 12v input. Measure the time from when that Terminal 1 input goes low (0v) to when the delay box releases (0v) the +12v to the transbrake. This should correspond to the delay time in the K&R.

You are looking for this value to repeat as it will likely be off slightly from the actual delay setting.

I agree, but we’ve been told only one 12v channel is possible.

^^^^ I didn’t catch that. This is a Racepak with only one (1) 12v event to be recorded? I don’t understand this. What’s using up all the +12v channels?

quote:

Originally posted by markemark:
^^^^ I didn’t catch that. This is a Racepak with only one (1) 12v event to be recorded? I don’t understand this. What’s using up all the +12v channels?

Sportmans are equipped with only 1 12v event. I am sure you could probably buy a vnet sensor that might be able to add more but I am out of open channels so I would be looking at 600plus to do what we are saying.

You had some instructions on how to check the delay with the grid, which I also have. I could use that to confirm the box. The rest I think I can get from the racepak and do not feel that is an issue - for reason the graphs overlay track to track and run to run very very well. What I mean again by that is the trans brake signal drops to 0v, crack of tire overlays other graphs same time out. Only thing I see different in graphs is sometimes where the car gets up on tire after the crack the peak is slightly higher , and I usually see a few thousands in my 60ft when that happens. Its a heavy 5.6s car so that can be expected and well after the beams are broke.

Don’t discount the role of staging in this as well.

I don’t have any feel for [staging depth] vs [RT change] but we’re talking about thousandths of a second here.

To go back to the original question, I make tiny changes to the box all the time. But I also don’t have tons of history at any one track; I probably don’t go to any single track more than 2-3 times per year.

We have a vehicle roll out tester in a 4.30x/4.40x dragster. You'd be surprised at how accurate these cars are. So far we have not blamed a bad light (late or red) on a car/roll out problem. It was installed in January of this year so we have roughly 50 passes on it with my son driving it. He's in his 20s so he should be better at the human part that I am, but we all get into slumps and that was the leading factor in us getting the new toy in the first place. What we have seen is it's all driver related.

My vote here is to focus on the human factor in all of this fix the driver and fix the problem.

On the question about removing 0.005 or 0.010 if you are setup on a teen RT number all day, my experiences are similar to what others have shared. I think the human variability for me and my son ranges anywhere from 0.000 to 0.015. If you setup on a 0.015 tree and really crush it, you will end up in the 0.00X range, the bad thing is if you even slightly miss it you end up in the 0.025 range. This is all in the driver reaction to seeing the light and letting go of the button. If we were robots we would not have this discussion, but the variability is all in the driver from my experiences. When I am doing really well I'm VERY focused and consistent on button pressure, hand placement, and thumb/finger orientation on the transbrake button. If you setup your practice tree in your car you'll see how much variability you can introduce in this regard. Or if you intentionally move or change your finger/hand/release method on the practice tree button you can get a feel for how much impact this can have.

Friday we got rained out so I put some graphs together from racepak. These were random graphs from different day and tracks. As you can see the car is very consistent in two step RPM which was brought up. And also the crack of the tire which is the first little spike. These graphs are zoomed way in and I put some time markers and it shows the "dead time" of about 61ms.

https://photos.app.goo.gl/ygPjTYmc2D4qEbgk9

Saturday I was double entered and took both entries to the 4th round where the sun set behind us at the starting line and directly on the tree washing everything out. I was .010-.019 on every hit prior in both no box and box. Then I was .045 & .046, putting me on the trailer.

Sunday for time shots the skys were overcast and my first two hits between box and no box were .048 & .049 WTF! No blaming the sun this time as I honestly thought it was the day before. So we got busy making adjustments. I threw a few shims in the just in time button, added air to front tires and pulled some out of the box. By second round we had reaction times repeating from .008 to .014. Took both no box to the quarter finals where I let the guy back around me by .001. And went to the Finals in super pro to unfortunately get put in other lane I had not run all day and did not turn on the win light.

So moral of the story is I think the car is deadly consistent - I had at least 5 slips that were within .001 to the 330ft and the driver is the wildcard. For whatever reason I went way slow but consistently slow which allowed me to adjust the car back to me and be successful the next day. I was told years ago to not try to see the tree different and I have always stuck to that. Honestly I don't think I could change my routine and whether top or bottom I see it very much the same. This is evident in the reactions times tracking exactly the same.

I will add I was in the lanes on two separate times and did hear others asking people if their reaction times were super slow? Did something shift during that first day to cause the RT change. And I had at least 3 opponents go WAY late on me and they are very good racers at a lot of the big money events.

This message has been edited. Last edited by: ski_dwn_it,

Are you slower at night? I know I am. That might explain some of the RT change when it got overcast. You are running at Beaver right? I always hated the sun angle from morning to evening when I ran there. Almost had to wear sunglasses in the evening with the sun setting in your face.

quote:

Originally posted by moparacer:
Are you slower at night? I know I am. That might explain some of the RT change when it got overcast. You are running at Beaver right? I always hated the sun angle from morning to evening when I ran there. Almost had to wear sunglasses in the evening with the sun setting in your face.

No I don't see issue at night.

I have run at Beaver and agree the sun setting is really tough there. Not yet this year though. Been to Numidia, PGH, and Empire - rain is killing us here in PA.

quote:

Originally posted by Triple Nickel:
We have a vehicle roll out tester in a 4.30x/4.40x dragster. You'd be surprised at how accurate these cars are. So far we have not blamed a bad light (late or red) on a car/roll out problem. It was installed in January of this year so we have roughly 50 passes on it with my son driving it. He's in his 20s so he should be better at the human part that I am, but we all get into slumps and that was the leading factor in us getting the new toy in the first place. What we have seen is it's all driver related.

My vote here is to focus on the human factor in all of this fix the driver and fix the problem.

On the question about removing 0.005 or 0.010 if you are setup on a teen RT number all day, my experiences are similar to what others have shared. I think the human variability for me and my son ranges anywhere from 0.000 to 0.015. If you setup on a 0.015 tree and really crush it, you will end up in the 0.00X range, the bad thing is if you even slightly miss it you end up in the 0.025 range. This is all in the driver reaction to seeing the light and letting go of the button. If we were robots we would not have this discussion, but the variability is all in the driver from my experiences. When I am doing really well I'm VERY focused and consistent on button pressure, hand placement, and thumb/finger orientation on the transbrake button. If you setup your practice tree in your car you'll see how much variability you can introduce in this regard. Or if you intentionally move or change your finger/hand/release method on the practice tree button you can get a feel for how much impact this can have.

i agree with everything here for sure and happy to hear another that simulates what I am seeing. Obviously we are all human - I guess I proved that going from teens to consistent mid 40s this weekend even from day to day, then making changes to car and getting back into a consistent .008-teens range again.

In the decades of letting go on the top, the biggest variable (and there a lot of others that you guys have mentioned) is the "variation, distraction of the human brain inside the helmet". Get that right on certain days and you can just let go and let 'em roll. Other days, no matter how much focus you try to gather up..you be .020 when it felt like a .00.
Extremely similar to golf. Some days you swing and you just don't miss. The next day or even the next golf shot, it looks like you forgot how to golf.
It's in the mind 90% of the time, not the button, delay box or chassis. Sure, those things are important but they are down the list from what the brain can do to reaction times.
Have a great day, Be Double-0 and enjoy it.
Jok

quote:

Originally posted by markemark: I believe failure to repeat is operator, then mechanical.

I believe this to be true also. I have a ratio, me not the box. Not sure why that is but, .001 in my box translates to .004 at the start. When Tony Morris drives my car it's .001 to .001 for him. I raced at SGMP recently for the first time in 18 months and the 1 to 4 ratio proved still valid. Still didn't keep me from going .010 red in the first round.