Critique my 1st logs from VE/MAF Tuning
07-25-2012, 04:13 PM
#1
Critique my 1st logs from VE/MAF Tuning Getting my feet wet and recently completed my 1st set of AutoVE and AutoMAF tuning. It's rather hot out so that doesn't help the logged data, but the tuning was done in the evening when it was cooler out. After reviewing the logs it looks like I'm getting in the ballpark, but wanted some input. Looks like my WOT A/F could use some tweaking and I can probably dial in my BEN's a bit better.
NOTE: AutoVE and AutoMAF was performed independently, and the attached log is the tune with everything turned back on (DFCO/LTFT/STFT/etc). I'm obviously lean in the 20/30kPa range since DFCO is active. What do you guys think?
Car is a 1998 Z28 A4
180* Thermostat
SLP Lid w FRA mod
Ebay Longtubes
3" Y-pipe w/ no cats
Magnaflow cat back
EGR/AIR/PCV deletes
NOTE: AutoVE and AutoMAF was performed independently, and the attached log is the tune with everything turned back on (DFCO/LTFT/STFT/etc). I'm obviously lean in the 20/30kPa range since DFCO is active. What do you guys think?
Car is a 1998 Z28 A4
180* Thermostat
SLP Lid w FRA mod
Ebay Longtubes
3" Y-pipe w/ no cats
Magnaflow cat back
EGR/AIR/PCV deletes
07-25-2012, 06:56 PM
#2
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It is coming along good - like you said, a little more fine tuning can be done. One thing - do you have any exhaust leaks? Some of the LTFT readings look like you might have leaks while idling... wouldn't be surprising - one of the downfalls of cheap headers is they leak due to not being welded very well where the primaries meet the collector...
Also, you are not using a serial connection from the wideband to EFILive - there are some spikes in the wideband readings that are common to ground issues when using analog... I highly recommend getting a serial cable from TAquickness.com and using that to connect the wideband serial output to the EFILive serial input - you will notice a big difference!
Also, you are not using a serial connection from the wideband to EFILive - there are some spikes in the wideband readings that are common to ground issues when using analog... I highly recommend getting a serial cable from TAquickness.com and using that to connect the wideband serial output to the EFILive serial input - you will notice a big difference!
Last edited by BLK02WS6; 07-25-2012 at 07:03 PM.
07-25-2012, 09:09 PM
#3
Funny you mention that because we found slight leaks on both sides where the collector mates to the Y-pipe. How can you tell from the log that there are exhaust leaks by looking at the LTFT's??? I always wondered if you could tell something like that from a log.
As for the serial wideband cable, can that be used with EFI Live v1? I don't have V2.
Thanks for the info!
As for the serial wideband cable, can that be used with EFI Live v1? I don't have V2.
Thanks for the info!
07-25-2012, 09:51 PM
#4
TECH Senior Member
Also, when you log for correcting the VE or MAF, keep do not exceed 24 pid channels...
on the PIDs tab look at the bottom of the window, it says the pid channel count, keep it 24 or below to maintain the fastest update/sample rate.
on the PIDs tab look at the bottom of the window, it says the pid channel count, keep it 24 or below to maintain the fastest update/sample rate.
07-26-2012, 10:33 AM
#6
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No, with a V1, you are stuck with analog...
As for the exhaust leaks - for one, the LTFTs will be different from each other during idle and low RPM when comparing one side to the other - and then when you get up to cruise RPM, they become the same again. Basically, you see this because the exhaust will actually pull air into the exhaust pipe through the leak at idle and low RPM and that air is seen by the O2 sensors - effecting LTFTs. Then, when you go up in RPM, and there is more pressure in the exhaust, it doesn't pull the air in through the leaks. Tried to simplify it, but does that make sense?
Another way you can see exhaust leaks causing issues is if you have +LTFTs at idle, and as soon as you start to give it gas and move the car much, they drop right down. The reasoning is pretty much the same explaination - and because the fuel tables don't change drastically for such a small change in load/rpm, you know it is another reason causing a large difference in LTFTs - the reason is the false lean it sees from the leaks.
Again, simplified, but hope it makes sense...
As for the exhaust leaks - for one, the LTFTs will be different from each other during idle and low RPM when comparing one side to the other - and then when you get up to cruise RPM, they become the same again. Basically, you see this because the exhaust will actually pull air into the exhaust pipe through the leak at idle and low RPM and that air is seen by the O2 sensors - effecting LTFTs. Then, when you go up in RPM, and there is more pressure in the exhaust, it doesn't pull the air in through the leaks. Tried to simplify it, but does that make sense?
Another way you can see exhaust leaks causing issues is if you have +LTFTs at idle, and as soon as you start to give it gas and move the car much, they drop right down. The reasoning is pretty much the same explaination - and because the fuel tables don't change drastically for such a small change in load/rpm, you know it is another reason causing a large difference in LTFTs - the reason is the false lean it sees from the leaks.
Again, simplified, but hope it makes sense...
