Thread: Megasquirt MS3
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sjf911 sjf911 is offline
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Join Date: Dec 2006
Location: Idaho
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Megasquirt MS3

I have finally had a chance to install my MS3 module in "upgrade mode" this week with the current "beta" firmware. I roughed out a manual 16X16 VE table and used the import-table function for the AFR and spark maps from my MS2 tune.

Tuning with TunerStudio VE Analyze Live (VEAL) is incredible with MS3. It lets you rough out your VE table quickly on "easy" setting (cell resistance to change) and then you can use the harder settings to gradually "polish" the table. After less than an hour of varied driving my table is probably 85+% including the boosted cells. The most immediate benefit was noticeably improved idle quality. The increase in VE resolution over MS2 is very noticeable at low pulse-width operation.
The only issue I have encountered appears to be a problem with the way TS employs its serial communication compared to Megatune. Serial dataloging gets corrupted easily even with the direct USB connection available on the MS3 card. OTOH, the built-in SD card slot gives you much higher temporal resolution dataloging without the noise corruption.

My current setup utilizes the original CIS AAR for warm-up idle control and the original CIS decel valve for vacuum limiting on throttle lift. The MS3 gives me the option to reinstall my 4-wire stepper idle valve (Clewett) to do the warm-up idle, vacuum limiting, and closed-loop idle control all-in-one to simplify my plumbing. There is also a new acceleration enrichment algorithm available that I am interested in trying as I had limited success with X-tau and the standard enrichment algorithm with MS2.

AC idle-up, fully sequential injection, and LS2 CNP ignition will be added when the MS3x board is released. Also, I will probably switch to the Carrera 3-wire Bosch PWM idle control valve at that time as the "experts" suggest that PWM valves are better than the steppers for closed-loop idle control. For those interested, MS3 + MS3x gives you on board closed-loop electronic PWM boost control capability.

I have to completely redo the engine and engine bay wiring harness for the MS3x so an engine drop may be in my near future. I plan to eliminate the megasquirt "relay board" and use a Bussman 15304 RTMR panel for relays and fuses. I also need to improve 12V+ ampacity in the engine bay.
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Old 07-03-2010, 05:17 PM
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