LM1 doesnt match EFI Live

[minytrker]

I noticed that the display and what the computer is logging doesnt match my display on my lm1. Its off by almost 1. In 4th gear wot the lm1 was reading 12.2 the computer was logging 13.1. I just switched to a new laptop so I must have something setup differnt than my old one. What do I have off?

[SSpdDmon]

I noticed errors like this with my LC1. I was on the dyno at a local shop with a friend's car and the LC1 was reading 12.0, but the dyno was reading 13.0. I tried to get some answers from Innovate and they brushed me off saying something along the lines of it being the analog wires fault. There's too much room for error or something...

Here's the thread:
http://www.innovatemotorsports.com/f...ead.php?t=4118

[minytrker]

Hmmm. I wonder which one I should trust, efi or the lm1. The lm1 is reading 14.6/14.7 when at cruise so I would thing the lm1 is correct. EFI is reading high 15's. In closed loop the car isnt making any corrections either, so I would like to believe I have my VE table dialed in, because it was really off giving my an afr of 15-16 I would think I would see the car trying to correct for that.

[minytrker]

I plan on spraying a 100 shot on the dyno tonight if eveything on motor checks out. So if the lm1 is right then im safe at 12.2 if efi is right im going to have some major problems.

[Garry]

Are you using the LC-1 as output to both LM1 and EFILive? If so, are you sure the outputs are programmed correctly?

[minytrker]

Are you using the LC-1 as output to both LM1 and EFILive? If so, are you sure the outputs are programmed correctly?

Yes using it for both. Thats what I am asking. I never noticed it before on my old laptop but on this new one it seems to be getting worse.

[johnv]

Yes using it for both. Thats what I am asking. I never noticed it before on my old laptop but on this new one it seems to be getting worse.

There is a tread here some where about altering the calc for voltage offset using a "voltage offset spreadsheet".

Mine was off with the std calc in EFI, after altering calc it matches perfectly.

Definatly trust the LM1 readout over EFI and make sure you do a free air calibration, preferably with sensor out of exhaust and engine running with a few revs so voltage from charging system is where it would be when logging .

[minytrker]

I checked the lm1 against the wb at the dyno and it matched perfect so that means I need to find that calculation for efi to correct it in there.

[bK]

Do you know what your voltage offset is? It’s extremely hard not to get a voltage offset between your WBO2 and Flashscan.

I setup my LC-1’d 2nd analogue output to push 2v no matter what the AFR is, on Flashscan that comes in at 1.97V so I use in my calculations to correct the voltage offset to get my correct AFR reading in Flashscan.

I posted how I fixed the voltage offset on this topic> http://forum.efilive.com/showthread.php?t=1530&page=3

LC-1 is wired in and working perfect..... Well almost perfect it's got the slightest ground offset of 0.03. I've worked this out from changing analogue 2 output to a flat line of 2V at 10:1 and 20:1 AFR. The reading I get from the Flashscan is 1.97V.

So to get my the calculation for correct Wideband AFR to work perfectly I need to modify the SAE_GENERIC.txt from:
({EXT.AD1}*3)+7.35 TO
(({EXT.AD1}+0.03)*3)+7.35

[Garry]

I setup my LC-1’d 2nd analogue output to push 3v no matter what the AFR is, on Flashscan that comes in a 2.98V so I use in my calculations to correct the voltage offset to get my correct AFR reading in Flashscan.

That's a good suggestion! Maybe this should be added to the LC-1 install how-to ... .02V already can make a difference ... not much, but it's a way to trouble-shoot the install before you even get started with tuning ... if somebody comes up with - like 1V off of what it's supposed to be, I recon it's time to check the cabling ... Maybe though one should use the output that's supposed to be used later for the EFI input be set to a fixed value, that way any variances on the side of the LC-1 can be outruled ...