Ignition Options 77 280z w/83zx turbo swap

[Z_Dust]

I have a 77 with a 83zx turbo engine swap. My setup is a completely stock 83zxt with MS-II PCB3 using version 2.25. I am using the direct coil control option with the zxt distributor hooked up to MSII as shown in the manual

 

When it comes to "Ignition Options" setup I am at a loss. Is there someone out there that can shed some light onto these options. I dont completely understand how each affects tuning/setup so pretty much I would be guessing.

 

Trigger offset

Skip pulses

Predictor Algorithm

Predictor Gain

Next Pulse Toerance

-Cranking %

-After Start %

-Normal Running %

Ignition Output Capture

Cranking Trigger

Coil Charge Scheme - Standard Coil Charge

Spark Output - Going High Inverted

Maximum Spark Duration

[Matt Cramer]

The MegaManual has an explanation under Configuring Megasquirt-II. I'll give you a short run-down here.

 

Trigger offset: How soon BTDC you get the signal from the ignition input. Depends on where the distributor timing is set.

 

Skip pulses: How many pulses it will ignore before cranking up. Typically 3, and generally only affects cranking.

 

Predictor Algorithm and Gain: How Megasquirt tries to predict when the ignition pulse will arrive. The explanation for this is very long.

 

Next Pulse Tolerance: These values are designed to filter out false triggers. Higher values filter out fewer pulses, while setting this very low can screw up the ignition during rapid RPM changes.

 

Ignition Input Capture: Should be Falling Edge.

 

Cranking Trigger: Unless you are running around 10 degrees of trigger offset, set this one to Calculated.

 

Coil charging scheme: Set it to Standard Coil Charge. The only time you'll change this is when you are using a Ford EDIS ignition, where the pulse duration controls the spark advance - normally, the pulse duration controls dwell time.

 

Spark Output - Should be Going High (Inverted) any time you are using the VB921 to drive the coil directly. DO NOT CHANGE THIS.

 

Maximum spark duration: Used for calculating coil dwell.