how many of you run megasquirt as a piggy back
 

i'm just trying to see if there is any benifit to running a megasquirt as a full stand alone. if you can do all the same fuel and spark controll by using it as a piggyback then why the extra work? Are there any features that don't work as a piggy back? Before you all jump and attack. I am new with megasquirt and considering it greatly.

With a 94 the MS is able to run full standalone easily. I dont know why you would bother piggybacking it.
I can understand piggybacking on a 99+, since the alternator, fans, VVT, etc is all controlled by the ECU, but even then you can make circuits to control that stuff.

I have a 94 with MS installed in a parrallel setup. I did it this way because 3 years ago when I did the install it was how most people were doing it and no one had AC support figured out. Right now the only thing that my stock ECU controls is idle. Once I get MS3 running great I plan on switching to full standalone.

I plan on finally switching to standalone. Really the only thing I gain/lose is idle control.

Any deficiencies with letting the stock ECU control idle/fans? I'm curious why'd make the switch if your parallel setup is working. Just for simplifying things?

Money, hoes, and clout. The stock ECU is only handling idle, that's it, it's dead weight and complicates the install. plus parallel harnesses make me want to die.

I might call it a slight deficiency that with the stock ECU controlling the fans, they come on at a slightly higher temperature than I'd like. I'm in the process of upgrading to MS-II and while I have the case open I'm pondering adding the fan control circuit.

I hadn't thought about that...it gets pretty frickin' hot down here in the summer.

so now you dont need piggyback to have AC working?

The great Brainack finally acknowledges the inherent awesomeness of a standalone install? Be still my heart!



https://www.miataturbo.net/forum/t20954/

parallel installs are so 2007; only did like 2 all of last year, and only for people that worried about emissions.

Heck MS-III has an idle up with a/c activation feature now :) The closed loop code alone for MS-II alone is supposed to be pretty good. The few times I've driven standalone I had no idle issues myself, with a/c wasn't any better/worse than a setup running Hydra...

If you let MS control the fans, you can get rid of the stock thermoswitch, making a coolant reroute easier when you delete the front thermostat neck.

Already got a parallel setup on the way...

Dammit. I can't make up my mind.

I have to send it to you anyway to set it up for 90-93...should I ditch the parallel and go straight to standalone? I'm doing MS2 so my idle control shouldn't really be an issue...

swap out the transistor on the Middle LED with a 2n2222, then use it for fan control instead of a warmup mode light...this is how my msq I sent you is setup.

I hate you and your crazy way of doing things.

it's an awesome way. the only issue is the 3904 transistors that come in the kit, the v2.2 boards used pn2222 transistors which are rated for 1A, the 3904s found on the v3.0 are like 300mA; not enough for the fan relay.

I do kind of like the idea of using the middle LED, if for no other reason than it leaves the proto area free for other stuff. The MS2 spare ports configuration page suggests to "remove R27 and connect the transistor base resistor to the end closest the heat sink." It doesn't look like you did that part. Is it not necessary or am I missing something else?

warmup-1 goes through r27...dunno whyd you'd remove it.

Hence my confusion. I'll just do it how you did it and not worry about it, unless it doesn't work.