quote:

Originally posted by BD104X:
Not sure about the grid but what you describe is almost exactly what happens when the 7AL-3 boxes go bad. Car will run fine on one run but way slow the next. Timing lite will show timing rock-steady but if you bang on the box itself the timing jumps all over the place.

quote:

Originally posted by TOP38:
on the red box, the timing retards activate when they see ground,,, so internal grounding causes this problem.

quote:

Originally posted by TOP38:

quote:

Originally posted by BD104X:
Not sure about the grid but what you describe is almost exactly what happens when the 7AL-3 boxes go bad. Car will run fine on one run but way slow the next. Timing lite will show timing rock-steady but if you bang on the box itself the timing jumps all over the place.

Billy, on the red box, the timing retards activate when they see ground,,, so internal grounding causes this problem. The new ones, I think that are black, require 12v to activate ground so these are better,,, hopefully lol.

Advancing timing is another issue. I have heard that the earlier grids have issues. I would think MSD has the serial numbers on those known to have problems.

quote:

Originally posted by markemark:
I have heard that some racers (TD) using the ICT feature and Step Retard have experience engine damage which they attributed it to a bad MSD 7730 Grid box that was not retarding timing. They said there problems were resolved by replacing the 7730 box.

Grid “cannot” advance timing more than what you set the static crank timing to.

Here’s the mistake some Grid users make when setting the initial timing in Grid and even re-checking it anytime afterwards.

If the Maximum Timing Reference value in the Settings / General tabs does not match Ignition Timing / Engine RPM tabs Main Timing value you cannot set the timing properly. Also, all the Step Retards need to be disabled with no +12v applied when setting timing.

The Grid 7730 firmware should be SW Version 1.7.6 . To check what version you have, attach to Grid and select Help / About.

quote:

Originally posted by ts393c:
As for the timing it is set at 35 and the max is set at 35. I only use 1 step retard and it is activated when I spray nitrous.

I have been using this box for 3 years set up the same way. Never had one problem with it until this year. I know on the passes that it slowed up you could feel it. Like it was down on power. Maybe it was retard the timing.

quote:

Originally posted by OhiomafiaWireGuy:

quote:

Originally posted by TOP38:

quote:

Originally posted by BD104X:
Not sure about the grid but what you describe is almost exactly what happens when the 7AL-3 boxes go bad. Car will run fine on one run but way slow the next. Timing lite will show timing rock-steady but if you bang on the box itself the timing jumps all over the place.

Billy, on the red box, the timing retards activate when they see ground,,, so internal grounding causes this problem. The new ones, I think that are black, require 12v to activate ground so these are better,,, hopefully lol.

Advancing timing is another issue. I have heard that the earlier grids have issues. I would think MSD has the serial numbers on those known to have problems.

On the 7AL3...the step retard is active when it is removed from ground, or when 12v is applied. The new and old 7AL3s all work the same...MSD just reworded their explanation. It’s recommended that if not using the retard to install the zero chip and ground the retard terminal.