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MS3 1.4 firmware
Key changes and Gotchas - from 1.3.x and earlier
=======================
1. Baro
Previously the code used to divide by the barometer when calculating the fuel
pulsewidth. If using an old tune you need to enable the "old style" baro
calculation to enable the old behaviour.

2. CLT rev limiter
The TPS bypass rev limit setting has been removed, the standard hard limit is
now used in bypass mode to reduce confusion.

3. Closed-loop boost
The initial values table is now a bias table. This needs to be tuned as an
open-loop table using "setup mode" before enabling full closed-loop. See the
tooltips and manual.

4. On/Off outputs using bitwise AND
The meaning of threshold and hysteresis has changed, see the manual.

5. Other changes are covered in the Setting Up manual.

Key changes and Gotchas - from 1.2.x and earlier
=======================
1. Idle control settings re-arranged
Need to reset:
Stepper vs. PWM idle valve
Open-loop vs. Closed-loop
Output pin for PWM.
2. Closed-loop idle control
The settings are re-arranged to simplify setup, but existing users will need
to retune.
3. GM/TFI ignition settings changed.
4. MAF configuration changed.
5. VSS input configuration changed.
6. Generic PWM output type and frequency selection changed.
7. On/Off outputs enabling changed.
8. Various tables now use "kPa" instead of "%", the numbers should be ok.
9. VVT adds min/max duty settings, you may want to use them.
10. Two TunerStudio dash indicators have been renamed:
Not Synced -> Not RPM Synced
Half-sync -> Half-RPM sync
You will need to re-load you dash (right-click on a blank area of the dash
select Load/Save, then Load dashboard, then Accept) or update manually.
11. Rev limiting is changed. Check your settings.
12. Some "trigger wheel" users may need to change their tooth#1 angle if it
was close to 360deg or 720deg. (A previous bug was fixed.)


Key changes and Gotchas - from 1.1.x and earlier
=======================
1. MAF
There is a new MAF calibration implementation like MS3. The old method is
still valid.

2. Baro
The default settings for baro were on the MAP sensor calibration page
as 147, -47 with a tweak curve on top.
The new method sets these two numbers to zero and exclusively uses the
adjustment curve. 100% means un-altered fuelling.

3. Air-density
In previous versions, there was an internal calculation for air density with
a tweak curve on top.
The new method exclusively uses the adjustment curve. 100% means un-altered
fuelling.
Note: MAT does change air density and the speed-density equation relies on
this to estimate intake charge.

4. Spark output polarity
The name has been simplified
"Going High" - was called "Going High (Inverted)"
"Going Low" - was called "Going Low (Normal)"
DOUBLE CHECK YOUR SETTING BEFORE CONNECTING COILS.

5. Boost Control
To make things more intuitive we have now changed the firmware so that
- "Normal" is the most typical output polarity setting
- larger boost duty% numbers mean more boost.

If you are a new user starting out from scratch, then nothing needs to be
changed, just use the default settings.

If you are upgrading from a previous firmware version, then the Boost Output
polarity setting will be the opposite. For most users it will now be "Normal".
This is true whether using open- or closed-loop boost control.

If you're using closed-loop, nothing else should need to change.

Open loop boost users most likely need to set their table so that:
new_cell_value = 100 - old_cell_value

Remembering that more duty = more boost.

6. Serial protocol
The firmware now uses the "newserial" protocol. This requires
compatible tuning software and firmware loaders.
(Note, it you want to revert to an older firmware version you will need to use
the new firmware loader, or use the boot jumper.)

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i would have expected that very long dwell timing would retard timing as rpm increases rather than advance it...

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"The LS1 built in coil igniters (the amplifier that drives the coil's primary current based on the sequencer signal) will follow the sequencer signal pulse width. When the signal from the sequencer is high (3 to 5+ Volts - with very little current from the controller, a few dozen milliAmps), the coil current will be building. When the signal from the sequencer is pulled low (shut off), the coil will spark. The duration of the signal from the sequencer determines the dwell (though the coil igniter limits this to no more than ~8 milliseconds).

As the dwell time increases, the peak coil charge current increases. The coil output current is not as linear. The LS1 coils do not fully saturate until around 8 milliseconds, but the spark energy does not increase much when the dwell exceeds 6 milliseconds. So stick with a 'running' dwell setting near the design value of 5.6 to 5.8 milliseconds. This will keep the coils cooler and extend their life. Note that MegaSquirt-II uses a nominal dwell setting, called the 'maximum dwell', at 12.0 Volts and adjusts this for the continuously measured running voltage (since higher voltages charge the coil more quickly, the dwell is shortened, and conversely, low cranking voltages need extended dwells to properly charge the coil for easy starting).

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