What kind of idle control are you planning to use?
I`m not quite sure yet, I was/is hoping to use some sort of stepper motor valve. BUT, I have heard rumors that that is not possible when using megasquirt to also controll ignition. I have yet to find conclusive facts of this.
I always find it difficult to navigate the MegaSquirt pages, and sometimes I get more confused by reading about different versions of the code and hardware - and the combinations of this.
I found this resource, though, which lines it up pretty nicely:
http://www.megasquirt.info/MS%20FAQ.htm#versionsThe bottom line of that is that if you have a 3.0 board, then you can install the MSnS-E software with ignition control and a vast collection of advanced features. In that case you don't need the piggy back board of "MegaSquirt-II" (which is not the second version of the system, but an upgrade with a faster CPU). I don't like the idea of having a piggy back board in an IC-socket in a critical part of my car, I would'nt be able to stop worrying about when it would fall out due to vibrations, but it seems the II-verison has some interesting features. It's just almost another product.
MSnS has pretty flexible idle control features, it seems to be described here:
http://www.msextra.com/manuals/MS_Extra_Software_Manual.htm#idlevThe code for that is also freely available, but it appears it hasn't been updated the last 9 months:
http://megasquirt.cvs.sourceforge.net/megasquirt/msns_extra/msns-extra.asm?view=log(note that all the code is in one 14000+ lines assembly file!)
Will you fit an oxygen sensor in the exhaust or run it in open-loop method?
I newer expected to find any maps for the N9 engine, so I orderd a widband O2 sensor, using this I can set a "target value" for A/F ratio. Hopefully this will make tuning less troublesome
Sounds like a good idea! You will have to take it to a rolling road to have it properly set up, however. I've been told that there's a guy here in Eastern Denmark with good MegaSquirt experience *and* a rolling road, so my idea was to persuade him to help me if/when I decide to take on the project.
Are you going to run a standard cam?
When I first bought my murena It was fittet with the complete S-kit, (cam,solex,lighter flywheel, different distributor, different exhaust) Unfortunatly I managed to damage my cylinder head, when inspecting the camshaft it was to worn to refit. I am currently running the standard camshaft (with the S-distribuator) In the future I plan to have a new performance camshaft installed (any recomendations?)
Mine runs a Holbay Fast Road cam and I can recommend that (and I think Holbay may be able to recut your old cam), but since it has a rather big overlap it may give challenges with MegaSquirt, especially if it's controlled primarily using manifold air pressure. With a carburettor, the cam has no problems, however, though the idle is obviously a bit rough and it likes running somewhat higher RPM than the standard cam. Positive side is that it revs up very fast, and above 3000 rpm it's really a rocket. It also doesn't die out in high RPM and the previous owner of my car actually spun it to 7000 rpm once, and still didn't feel it was having problems filling the cylinders. An important factor with such a cam is the exhaust manifold - the standard cast iron manifold probably will not work well on this cam. The inlet side, however, seems to be less critical - though mine was also born with the twin solex'es, when they were worn down beoynd repair, the were replaced with the 34CIC and the standard 2.2 manifold. As it spins easily up the revs, it's obvious that that side is not restricting performance much.
That said, however, if I do convert the car to fuel injection, I'll fit four individual throttle bodies (or rather two pairs), but that is mostly to bring it closer to the original state it had, with the twin carbs, than to boost performance.
Interesting to see that... it must be somewhat narrow for the Murena? Well I was referring to the manifold, but as you are running the standard cam, there's probably not any big gain by switching.
please continue to ask questions, sooner or later there will be something I have forgotten/ not tought of.
Well your experiences are certainly going to be of help to others, so I'll be more than willing to share my thoughts with you and discuss anything you'd like!
- Anders
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