ECU talk (MegaSquirt vs. VEMS)

[Ben Fenner]

All right, I've ruled out Calum's ECU daughterboard. The price is right 
($350 for Realtime), and the tuning process is do-able (most aspects 
tunable via windows based GUI program) but there is no support for 
anything the stock ECU doesn't support (obviously). This means no 
wideband 02 sensor input, no EGT sensor input, etc. This was the deal 
breaker for me.


As you may recall, the other option was the VEMS unit. I'll get back to 
that.


I started researching MegaSquirt, and once again the price is right 
($250 for parts, plus another $150 for random stuff), and I was very 
interested in building my own. I'd love to give the soldering iron a 
workout. The tuning process is what you'd expect from a stand-alone ECU, 
so that's fine. I just can't figure out if it supports wideband 02 
sensors. I know it will take the input, but does it throw away 
everything but the narrowband info? And if it does support WB02, why is 
there an entirely seperate WB02 board to build? Does anyone have any 
info on this?
Now I'm looking around for the ignition controls, and what do you know, 
MegaSquirt is a fuel-only system. It does not provide ingition control. 
I should have known, given the name. Oh wait, MS-II supports ignition? 
Okay, We're back on track, I guess. I could always use the stock 
ignition as well... But that's no fun. Now, any provision for exhaust 
gas temperature? No. Not from what I'm reading. So, it's got ignition 
support, sort of as an afterthought, and no EGT.

It seems MegaSquirt isn't going to cut the mustard either.

So, I'm back to the $700 VEMS, which does WB02, EGT, ignition (with 
coil-on-plug) and pretty much anything you'd ever want, for less than 
half the price of anything else out there (SDS, Haltech, F.A.S.T. 
BigStuff, AEM, Motec, etc.)

Thoughts?

-Ben Fenner
1994 Black SE-R (going turbo)
1994 Black SE-R (with sunroof)