MSD Grid to check Delay Box Accuracy
I’m re-posting this because the original posting link is corrupt.
To check the Delay Box accuracy / repeatability with Grid you would follow this method of wiring / programming. The delay box would need to have a +12v input to trigger using this method. NOT a ground input.
Attach any Step wire to the delay box Trigger Terminal. Nothing will be programmed into the Step function.
In Grid Data Acquisition / Start Recording tabs program the Engine RPM Above to 500 and the AND to whatever Step wire you are using.
In Grid Stop Recording tab program the Engine RPM Below to 100 and the Max Record Time to a minimum of 30 seconds.
Here’s what happens when you push the TB button. The +12v will turn ON the Step function in Grid along with arming the delay box. The Delay Box is also outputting +12v to the TB solenoid and Grid Launch wire. This will also start the Grid Data Acquisition record feature.
When you release the TB button the Step turns OFF in Grid and the delay box is timing out. When the delay box times out the +12v is removed from the TB solenoid and the Launch wire in Grid.
In the Data Acquisition you want to measure the time period from when the Step function goes from High to low, to the Launch input going from High to low. To accurately measure this time period you need to expand the acquisition to the maximum resolution to set the cursors on the transition lines of Step and Launch.
In the photo below is a friends Dedenbear CC3 I was using set to 1.000 of delay. As you can see it is very accurate and did repeat several times when checked.
In the Elite 95 delay box that I am now using, this box is consistently longer in delay by 0.0025 seconds. As long as it repeats, then everything is working properly.
Just checked my KR pro cube.
First hit .996201 second hit .996203
So mine is .00378X quicker.
You are always full of great information and tech help. Much appreciated.
Configuration: 3350#, 582 C.I.,
60 - 1.24
1/8 - 5.53@ 126MPH
1/4 - 8.73@ 159MPH
3700#+210lb driver, FULL interior, through mufflers, 10.5 tire.
60'-1.333 (IN 4000ft DA! Joisy Math excluded; 1.25sec using JOISY MATH.)
1/4 - 9.60@144MPH
How do you do it if your delay box input trigger is using a ground input? Mega 450...
394L Super Pro / Super Gas
I believe you cannot check the delay box accuracy with Grid if you do NOT have a +12v trigger input.
This is because if using a ground input to the Delay Box, you need to do a signal conversion to change the ground input to a +12v signal to Grid Step function input.
Doing this signal conversion will only decrease the accuracy / consistency of this event evaluation in the Data Acquisition imho. Especially if not using a diode in the relay coil circuit.
BUT, if you want to try adding a relay to do a signal conversion to see what the results are, please contact me and I’ll be more than happy to show you how to do this and share the results with everyone.
I’m always looking for racers willing to try what I believe might work with Grid.
Although I write methods about using Grid, I do rely on others to prove out my wiring / programming methods.
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