quote:

Originally posted by Iforgot:

quote:

Originally posted by markemark:

You have Grid so try using the Data Acquisition feature. Take your -.498 and .551 RT runs and zero both to launch release. Then overlay the runs.

Here’s what else you can do with Grid. Take the Pink Step 1 wire and run it to your TB button input on your delay box. In Grid Data Acquisition / Start Recording tabs program Engine RPM above to a value slightly less than engine idle and program the AND to be Step1.

This is what happens. When you push the TB button after you stage, Grid will start recording.

Here’s what you’re going to be looking at in your Data Acquisition after the run. From the time Step1 input “de-energizes” or goes low to the time the Launch Input goes low, should be “very close” to the same amount of time that you have programmed into your delay box.

What you want to do is get several acquisitions, zero to Step1 release, and then overlay them. Knowing the programmed delay for each run the differences in release should be the same time period from Step1 release to Launch release. You’re looking for any inconsistency in this time period.

Awesome!! I had been trying to figure out some way to do just that, but couldn't see the forest for all the $&)/! Trees!! I will be doing that tonight- going to hit Gulfport tomorrow if all goes well. You'd think a dude that programs DDC controls for a living would've thought of that but I never thought of doing it that way.
I had been doing the overlays, the grid is a fine tool for figuring out what's going on during a pass..thanks for the info!

That is a cool idea! I am not allowed to run the grid in my class but that is a cool feature and I would like to see what it tells you when you do.

This is one reason I went spragless.

Set my grid up today to record the time between button release and transbrake release. Also made damn sure I staged the car with the trans temp between 175-180 (some low as 160s, some high as mid 180s). Made one pass with the temp intentionally low (135) as kind of a "control".
If the grid data is correct (no reason to think its not), the box-brake-trans is working like it should be.
I still have to go over all of it with a fine tooth comb, but looks like the worst trans temp messed with the brake's release time is less than .008, and that was on the 135 degree trans temp pass. The others appear to be within a couple thou of each other, all of this over 6 passes which is not exactly a big sample size but I'm satisfied that nothing is wrong with the car, and trans temp is not messing with my reaction times as much as I thought. So why did my log book data indicate otherwise? Either the hydraulic fluid that was in there did mess with my r/t's more than the stuff I put in last thursday, or it was just purely coincidence.
So..the only possible explanation..my driver sucks!! It is what it is, next step is break out the practice tree and experiment with more buttons and button locations. And no idea why I'm messing up on the button all of a sudden, other than just getting older and slower..
Went out 2nd round both races today, first race took .013 stripe he was dead 6 I b/o .007 (cant remember but we were close on the tree) and second race bumped in too deep and went -.012 red against a 4.85 dragster, he was -.008 red. When it aint your day, it aint your day. Only had first round buybacks, at least I didnt have to buy back..

You are doing the right thing to determine the problem, eliminate the variables and resolve the issue. Good Luck.

I've always assumed I was the worst thing about my car.

Don't chase technical ghosts. Just look in the mirror.

Good machinery repeats, humans don't.

^^^^^this

quote:

Originally posted by David Friedenberg:
I've always assumed I was the worst thing about my car.

Don't chase technical ghosts. Just look in the mirror.

Good machinery repeats, humans don't.

100% truth..this human used to repeat a lot better 15-20 years ago. Tradeoff between physical ability and 'old age and treachery' is overrated!!
Maybe I should get my self sent in and 'freshened up'!!

quote:

Set my grid up today to record the time between button release and transbrake release. Also made damn sure I staged the car with the trans temp between 175-180 (some low as 160s, some high as mid 180s). Made one pass with the temp intentionally low (135) as kind of a "control".
If the grid data is correct (no reason to think its not), the box-brake-trans is working like it should be.
I still have to go over all of it with a fine tooth comb, but looks like the worst trans temp messed with the brake's release time is less than .008, and that was on the 135 degree trans temp pass. The others appear to be within a couple thou of each other, all of this over 6 passes which is not exactly a big sample size but I'm satisfied that nothing is wrong with the car, and trans temp is not messing with my reaction times as much as I thought. So why did my log book data indicate otherwise? Either the hydraulic fluid that was in there did mess with my r/t's more than the stuff I put in last thursday, or it was just purely coincidence.
So..the only possible explanation..my driver sucks!! It is what it is, next step is break out the practice tree and experiment with more buttons and button locations. And no idea why I'm messing up on the button all of a sudden, other than just getting older and slower..
Went out 2nd round both races today, first race took .013 stripe he was dead 6 I b/o .007 (cant remember but we were close on the tree) and second race bumped in too deep and went -.012 red against a 4.85 dragster, he was -.008 red. When it aint your day, it aint your day. Only had first round buybacks, at least I didnt have to buy back..

I should have knocked on wood or something after I originally read this post, having the same issue lately. I have noticed that it seems to occur when I'm the faster car and up on the TB longer.
Having said that, I have a Grid and will be setting it up for this check, but I'm not sure the data proves that that much! I need roll out.

Just because the time being looked at matches the delay box only tells you the electronics are working not the mechanical aspect of roll out. Am I missing something?

All it does is show what the delay time actually is, but it will help eliminate any problems with your box.
My issue was 100% ME. Changed button and button location and low side, did a little work on my brakes, and now I’m hitting the tree better than I’ve ever been able to hit it in 24 years of racing!

I agree that good fluid is hard to beat, but if your oil is over 100° you have other problems. It's not changing much after that until it starts burning.

This Grid method I wrote about will verify if your delay box is repeating with the same delay output when programmed. Knowing that the delay box is repeating consistently should show you that issues with RT are something else.

To determine the roll out of your car you can use a simple table top practice tree. Set the tree to a .500 bracket tree, 1.000 delay and set your roll out to .000 . You can attach the practice tree to your vehicle transbrake button leads using some alligator clips if you don’t have a plug in. Or use a button similar to what you have in the car.

Take 5 hits on the tree to get your average RT. Subtract that number from .500. If using a delay box, from this number subtract any delay box setting over 1.000 that would give you a “Perfect” .000 light in your car. If the delay you use in your car is less than 1.000 then you would add the difference between the delay and 1.000 to your answer.

Bracket tree .500
My average on tree - .217
= .283
My perfect RT delay - .011
My car Roll Out = .272

Although my car roll out is .272 in this example, it is with the ignition settings that I have presently programmed into Grid while using this delay box. If I change settings in Grid, I can make this roll out longer if desired.

I have not used a delay box in over 17 years and never in a car. I recently purchased a box to do some experimenting with and perhaps try in some of these high dollar races. Checking the box delay with my oldest 7730 Grid shows it to be consistently fast in release by 0.005 seconds. If the box is set to 1.000 delay, Grid shows the release delay is 0.995.

As always, good info and thanks!

However, knowing what roll out should be will not tell me what it was on that one run where the bad reaction occurred. I see a Racepak in my future!

quote:

Originally posted by Pro_ET:

quote:

Originally posted by LIZZARD
the transmission temperature is in the 130-140 range, my car would not vary much (a few thou) from run to run. With the motor at same 140-150 range but the transmission temperature in the 145-155 range, I can normally expect an .015-.020 quicker ET in my car. Hotter, thinner fluids is my conclusion to that. I wouldn't notice any noticeable difference in RT's but there again I'm mainly footbraking.

I Seriously doubt your consistency issues have anything to do with transmission temps! Regardless of which fluid is in it.

After 40 degrees celsius, viscosity changes are minimal. 40 degree C is only 122 F. Also check your trans temps on the return road and not the staging lanes.
DEX III Chart

According to the Data, Lightweight Racing is the best for consistency!

So let me ask a question here. With the chart the most important thing for our use would be the Viscosity difference between hot and cold? (First two lines)

I have been using Dex6 simply because that is what my transmission guy recommends but had no data to back that up.

My thinking is the less difference in fluid Viscosity the smaller the difference in performance change. Is that your thoughts to?

It's amazing how the smallest things can impact reaction time.

-medication (especially allergy stuff)
-heat (sitting in the car sweltering more than few minutes)
-sugar
-caffeine
-time of day

I bet there is something you are doing or not doing health related that's changing reaction times.

If wish I was half as consistent as my car.

quote:

Originally posted by Curly1: I have been using Dex6 simply because that is what my transmission guy recommends but had no data to back that up.

My trans guy told me to use Dex 6 also and it’s all I’ve used the past 5 years with no problems.

Here’s why I like using Dex 6. No matter who’s name is on the bottle it’s the same formula. Why? It’s a licensed product.

quote:

Originally posted by Curly1:


So let me ask a question here. With the chart the most important thing for our use would be the Viscosity difference between hot and cold? (First two lines)

I have been using Dex6 simply because that is what my transmission guy recommends but had no data to back that up.

My thinking is the less difference in fluid Viscosity the smaller the difference in performance change. Is that your thoughts to?

Yep very cold vs hot and it's still going to be mininal. I'm looking for a big swing ie several .00x lights followed by a .077 out of nowhere and felt I nailed the light same as the others. Seems to be a pattern of 4th to 5th run and being the faster car. I use dex6 too.

Everyone is different also in the way track lighting effects their lights. I have been working on numerous things, but out of nowhere 3 years ago, I started to have drastically different reaction times at Gateway as the sun goes down and especially when the lights come on. I have found myself to drop around .025-.035 on the tree top bulb or bottom bulb racing. I believe a .010 drop at night with LED lights is pretty standard, but the .025-.-035 is a bunch. It does not seem to be as bad at some other tracks, but I have come to the conclusion that the main issue is me. Started experimenting last year with wearing amber tint glasses at night and they seemed to help me, but trying to figure out when to put them on is the trick.