Megasquirt for stock NA.
 

I would like to build my self a Megasquirt and get it running before I install my turbo. Why do I want to do it like this? Because I can learn about how it works in a relatively safer state. I figure if I have one that works first, and I know how it works then when I do install my turbo I will have less problems to deal with.

I am most concerned about the initial configuration of the unit. How do I get it tuned to work with the naturally aspirated engine if I only have the narrow band? I would like to convert the car to MAP as well.

Its little questions like this that have me concerned. I don't want to blow up my engine on first startup.

Well MS uses a map sensor by default so that will definately be converted. As for initial configuration you could use someones MSQ file off this site to start with. That should get you going once you set your timing correctly. I would suggest reading through the DIYautotune setup guide for their PNP unit. It will explain most of the basic things. After that start reading the megamanual. As for running a narrow band it works fine but makes tuning very hard. I would suggest picking up an lc-1 to do the tuning with.

I know tuning with a WB would be simple, except I have no where to plug it into my factory exhaust. The only real thing I can see seriously helping me is if the PNP guys release the maps for the 94/95 cars and eventually 96/97.

The lc-1 can simulate the nb sensor. I removed my nb and replaced it with my wb and my stock ecu does not know a diffrence. As for msq DIYautotune will be releasing the ones they use in the PNP but really any one form the board should work to get you started with just a few simple changes. Hell shoot me a pm with your email and I can send you mine for my stock 94 that works decently.

You remove the stock narrowband sensor, and you place the wideband into where it went.

You no longer need a narrowband with a fullstandalone megasquirt.

Or you can just take it to an exhaust shop and they will weld in a bung for you, for cheap.

This way you keep the narrowband if you ever want to quickly convert back to stock ecu. (You can convert back to stock ecu with the wideband, but it involves removing it and replacing the stock narrowband obviously.)

[QUOTE=shuiend;135850]The lc-1 can simulate the nb sensor. I removed my nb and replaced it with my wb and my stock ecu does not know a diffrence. [QUOTE]

x2, as Im sure many others on this board have as well.

I would suggest doing some reading of Jerry's manual and the megamanual

reddroptop you are correct, I don't know why I said I don't have a place for the WB, obviously I would just pull the NB and swap.

Heres two questions.

I have to utilize the controller that comes with the WB sensor? I cant just swap my NB with the WB and use the wires in the car.
I havent done much reading into how they work, that is why I ask.

Searching didn't answer this question, but do I have to do anything special to the MS to make it work with the AC on?

Yes

Nope.

Because every harness for every car is different, and the widebands are universal. Basically you unplug the stock narrowband, and there are no wires left hanging or anything. Just a female plug at the back of the head near the firewall. Then you run whatever wiring (6 wires usually) to whatever sensor from whatever controller. Then from the controller to a gauge/display and the megasquirt.

I consider a wideband gauge/display CRITICAL in any standalone install. Even if your laptop does have the reading on it from the megasquirt, it is not always convient or possible to glance down and see what your car is running at.

Well worth the extra $$$$.

I am not sure, A/C is for wimps :inout:

Where I live AC is pretty much not optional... the droptop makes that at least almost arguable, but I like my A/C. I'm proud to be a 6'1" 210lb wimp then ;).

As for MSing a 90-95 Miata and using AC.... you're AC is controlled by the stock ECU so when you remove it you'll disable AC normally. We had to whip up a custom circuit to control it for the MSPNP's and it works fine. I'll know on the 96/97 pretty soon...

Damnit that may suck royally if the MS isn't going to control my AC. If thats the case then I feel that I will have to run both ECU's which creates many more questions on my end.

Oh thank God!!! I read that I lost AC and about shit my shorts. :)

Yet another reason that JUSTIFIES why the PnP is more expensive than the regular unit and it WORTH it :D

We put alot of work into these things ;)

I assure you my A/C works and is cold as balls with my vented hood. With TPS idle issues are solved. Only room for further improvement would be a soft start circuit. The A/C clutch is magnetic, isn't it? :D

Sure you can. that's how I wired in my LC1... I took the NB out and when I was wiring up the LC1, I used the signal return wire from the original harness that's clipped to the coil pack bracket. So the original wire for the NB O2 is carrying the WB signal back to the MSPnP

Not everyone is running an LC1 :cool:

Edit: Now that I reread what you wrote, It doesn't matter which wideband you use, you could do what you wrote. What I don't understand is why.

Either you are splicing into the harness = bad
Either you are ghettorigging a pin to plug into the connector = almost as bad
Or you are chopping off the connector off the narrowband and splicing the lead into that = which isnt a bad thing if the stock sensor is dead, or you are hacking up a dead/free spare, but if you are hacking up a good stock one, bad.

Plus I wouldn't trust the stock wiring harness, who knows where that wire is going before going to the ECU. Not worth my time to check the schematics vs running my own wire.

The stock O2 signal wire goes straight to the ECU...

But you still need the controller at the harness right?

-------------

So if I want to keep my AC I will need to run the factory ECU and the megasquirt. Is that right?

How much extra complication does this make for me? Any downsides to using both instead of just the megasquirt? I dont quite understand how the factory ECU controls idle if the megasquirt controls the ignition and spark, are they communicating with each other?

if you get the Pnp you dont need both i believe found said.

That's true, but he's got a '97, and we're not quite there.... yet.

Yes I understand I wont need both, but thats not the question that I asked.
I applaud the efforts of the MSPNP people but I dont want to buy a PNP. I want to assemble it myself to save money. That is why I am curious to know what I have to do to retain the AC functionality and use the MS. I am sure that someone here is using a MS and has AC functionality.