First single & dual channel A/F runs with LM-2

" A man with one watch knows what time it is - a man with two is never sure"

First run of the new LM-2 today on the Mondial 3.2 liter with 44 DCNFs.
First of all, the built in rpm meter off the neg coil terminal would NOT take a smooth reading- very erratic - not sure if this was because of MSD or what, but drifted around. Will try it with a better ground later, or try the msd tach output. Another complaint is that the manual, only supplied on the CD, is NOT very good.

The first graph is at idle after a cold start-up. the car runs very smoothly, but there is around a 1 point A/F difference front bank to rear bank. Of course, it is idling fairly rich so that covers a lot of ills. It sounds and feels fine. You can then see where I blipped the throttle, and then the mixtures came together as the acel pump jet fired. This is the smaller pump cam that did not come on the 308s but was more comon on the 12s, and as compared to previous tracings this pump does not dump the A/F under 10 as before with the previous 308 DCNF pump.

The length of the sensor extensions only availed me one A/F sensor for the driving piece. this is with 135/F24/90, 38 mm venturis, and 52 idles. I could not really ever hold much of a steady throttle setting due to traffic and safety, so you are seeing many throttle movements. This is actually pretty good for an initial jet wag on a new application. Once wrm, it typically idled at 12 and cruised in the 12s-13s. There were ever so slight burbles with slow throttle openings at higher cruise rpm, but it would also take dumping the throttle at the same rpm without stumble. I'll figure it out. the good news is that it cruises typically in the 12s - 13s and the top end pull to 7000 stays at 13.4 and below.

More later.

On a non-technical note, above 4000rpm on an open throttle with eight 44 mm Webers and straight through exhaust this is the best sounding eight cylinder Ferrari anywhere.
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Good ideas - will test tomorrow. It is idling a bit rich as well in any event - see the weber tuning thread for details.

 

Well, I did check them both in air and there was a big difference. I recalibrated them both and this time to the same value for ambient air; Next time there was an idle difference of .5 - .7 AFR; Better, but when I changed sides it seems that the difference stayed and swapped sides following the sensor. that makes me think that the sensors are slightly different in there response. But then again, I noticed at higher rpm and gas flows the difference minimized to within a couple of tenths.

" A man with one watch knows what time it is - a man with two is never sure"

I'll look around for air leaks around the sensors as well, but this suggests to me that the measurments may be more accurate at high flow/rpms - at least they converge.

Shown below is the two channel graph, the LM-2 plus a Radio Shack 12v power supply, and the engine.
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tried the rpm today again this time with a better ground - still terribly all over the place and unreliable. I'm going to call tech support on Monday. The MAP is taken off an OBD socket, which I do not have. If you have OBD, it can read the rpm there as well, but in my app it is taking it off the (-) terminal of the coil. jm3 is suggesting an MSD tach filter, which may also be worth a try.

 

Made a pigtail into the msd rpm output and got a better reading - it still waivers a bit and reads usualy lower than the cockpit tach, but it's close.
Recalibrated the o2 sensors again - they read the same in ambient air but still have a 1.0 difference at low rpm that closes as rpm goes up - I did not push it so much or drive today. It's interesting that even though they are a point aprt sometimes, they mirror each other almost exactly. Afterwards, I found I may have a loose extender, but not sure of effect. Perhaps they are more accurate at higher flows.
I will also look at getting the MSD filter.
Slow progress as I figure this thing out.

Note: all these were smoothed to 1 second.
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That is exactly what I did and what I got. At least they are consistant.

 

Well, I can't understand that chart at all.

 

Noise. Not that you could tell it made a difference.

 

took it out for a drive last pm (less traffic).
The rpms seem to get more accurate once it gets abve 2500 rpm, within say within 250 rpm of what the tach says, much like at higher flow the sensors read closer to the same. This graph also has sample smoothing set at 1 second.
So, why are there not 2 channels of A/F? The cable will not reach to the cockpit from the port side. I guess I could blindly record 2 channel from the trunk, but I'd have to rig another 12v power supply.
I will just point out again that mine does not function just like it says in the book - well, it doesn't come with a book, just a CD -and I had to do some putzing with it to get it to take instruction.
I think now we are beginning to make some headway.
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Thanks - interesting that your AFR runs about what mine does, in the 12s.
I actually do have 2 A/F inputs, it's just I need a longer extension for one of them.