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whats t?he differance between megasquirt MS1 & MS2
will121 - 12/9/09 at 04:27 PM

whats the differance between megasquirt MS1 & MS2? and whats the advantage or do i need to run a silvertop zetec?

Ben_Copeland - 12/9/09 at 04:52 PM

quote:

The MS2 can fire the injectors up to 0.01mS where as MS1 can do it to 0.1mS this means if you have a lot of boost and massive injectors you can get a better control at low engine speeds. It also has stepper idle control, where as MS1 can only do PWM, in your case you wouldnt need anything that MS2 can offer over MS1 in my opinion, Phil


I asked Phil @ extraefi that question a little while ago

[Edited on 12/9/09 by Ben_Copeland]

BenTyreman - 12/9/09 at 04:53 PM

Off the top of my head, pros for MS2 include 10 bit ADC for higher resolution sensors, much higher resolution fuel pulsewidths (something like 50 times more resolution), more space for code on the chip so more features and the code is written in C so it's easier to modify.

Cons are fewer input/output ports (I think) and certain features (such as traction control) are missing.

If you have over-sized injectors then the higher resolution can help to a certain degree (there isn't much fixing over-size injectors). For a standard engine I don't think it makes much of a difference, unless you want the new features like Enhanced Acceleration Enrichments/X-Tau, separate AFR table, PID lambda closed loop control or hybrid SD/Alpha-N fuelling.

Lastly, MS1 development seems to have pretty much stagnated as the chip is now completely full of code. MS2 gets regular updates with new features. The next major release has full sequential fuelling.

BenTyreman - 12/9/09 at 04:59 PM

quote:
Originally posted by Ben_Copeland
The MS2 can fire the injectors up to 0.01mS where as MS1 can do it to 0.1mS this means if you have a lot of boost and massive injectors you can get a better control at low engine speeds.


Although that is one of the problems with over-sized injectors, a bigger problem is the balancing of the injectors at low opening causing the different cylinders to run different AFRs.

quote:
Originally posted by Ben_Copeland
It also has stepper idle control, where as MS1 can only do PWM


That's why there are fewer I/O ports. I have seen a modification that involves soldering connectors onto very small pads on the MS2 chip to regain the I/O ports if you don't use the stepper motor.