I'm not compensating at all.
To be honest, I set it up several years ago and don't remember if it's a little off, but it definitely was not 400 off.

I have multiple cars, all wired the same.

Glide @ 1600 HP.
Glide @ 1200 HP.
Glide @ 850 HP.

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What is the max amps the grid yellow wire can handle? Does it have a fly back diode / surge suppression?

I've researched the shifnoid on my car and it is really a 1980's Bosch starter solenoid ( the older removable cap type ) repurposed as a shifter pusher. ( Power glide so only one push )

Mine has the pull in and hold in windings in parallel so they are going to have a high current draw and should not be left on for more than a few seconds. ( In a starter application, the pull in winding drops out when the starter is engaged )

I'd run a relay with a fly back diode / surge suppression across the shifnoid positive and ground. The relay will have some delay in triggering and the shifnoid / shifter movement so that that into account.

 

It came with a relay, so there might be that delay (?)

 

Yep , and in theory, the orientation of the relay can have an effect on the delay. If the movable contact is facing forward, acceleration can reduce the delay. If facing rearward, increase the delay. If the movable contact is facing up or down, really bad tire shake might chatter a relay?

The only way to be sure is look at a data log and go from there. But even then, not enough sample rate can skew data. I'd say set it up to shift somewhat early then look at data.

 

I use a toggle switch on mine so the load is only on after I am ready to stage.

It's a pain holding it in first, but it gets too damn hot leaving it energized.

I also use two relays in series just in case.
I had one fail before.
Load in series, trigger in parallel.


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