Logs from Dyno run

[Bad Habit Z]

This is the log file from my dyno runs this past weekend on my stock 01' Z06 with longtubes and a Blackwing. I just started learning about MAF tuning and was wondering about a few things.

First off I can't figure out why the car is running so rich at WOT compared to the commanded AFR, but when when logging LTFT for < 4000 rpm all the cells are lean.

Also is the reading for MAF (lb\min) supposed to jump around like it does in this scan at WOT? I figured it would be a little smoother than that.

[5_Liter_Eater]

Need a little more info. Since I don't have your config I can't see the actual AFR. Are you logging a wide band during the run? When you are tuning your MAF is it with fuel trims or WB? If you're tuning with fuel trims it is nearly impossible to tune the upper RPM's since you will be in PE mode and fuel trims lock.

Just looking at the log with the default config what I do see is that the long term fuel trims are consistently at +20ish?!? If that is accurate that explains why you are running so rich.

Where in Houston did you dyno?

[Bill@HPTuners]

looks like you either have a vacuum leak or that blackwing completely fubared your afr

my concern is that first wot run where your at 500-600mv for a good portion of the run.

as far as why your commanded doesnt= your actual thats in the tuning unless theres a mechanical issue like said vacuum leak.

[Bad Habit Z]

Sorry, here is my config file.

I haven't really tuned the MAF at this point, I have just been logging and trying to decide / learn what I need to do.

The dyno was done this past weekend at HPE's Dyno day. They were rushing the cars on and off so mine didn't have much time to warm up, could that be why the o2's were reading like that at first?

So if the LTFT's are lean they will make it that much more rich at WOT?

I also couldn't figure out why it was so rich and didn't have a lot of timing but had the KR showing up.

[Bill@HPTuners]

your config file doesnt help us much at all.

[5_Liter_Eater]

If LTFTs are positive, that will be added to the PE ratio. So even though you are commanding 12.8:1 it is adding 20% more fuel. If LTFTs are negative, they lock at zero in PE and the straight PE ratio is used. ETC was over 180 on your first run so I don't think being cold was an issue. The O2 mV's do look really off on the first run though.

You need to do some street driving/logging and get your fuel trims in line after checking for vacuum leaks.

[Bad Habit Z]

your config file doesnt help us much at all.

lol, I just posted it because 5_liter said he didn't have my config so he couldn't see it.

So is the MAF reading supposed to jump around like that in the higher frequency #'s at WOT?

[Bill@HPTuners]

if you werent logging a wideband through your interface he's nobody will be able to see your afr

[Bad Habit Z]

ahhh, yea I am logging through my rear 02's. I ran the logworks and HPTuners at the same time and verified the wideband is reading the same as HPTuners is seeing.

[redhardsupra]

you have a descreened MAF dont you? i've seen a lot of MAF's flicker like that after being descreened. Look at the smooth dynair--that's what your MAF should follow. how did you 'tune' MAF?

from your O2's it looks like you either never entered PE, or just run very lean not rich, but there's still no way to see AFR so who knows what happened. there's knock, so i'd guess it's lean, which agrees with O2's.
that knock would make you drop about 30-40lbft of torque short on where you should be, right?

[Bad Habit Z]

The MAF still has the screen on it right now, I haven't done anything with the maf just yet as far as tuning is concerned, I am just trying to figure it out right now.

The AFR on both runs according to the wideband was hovering around 11.6x:1 throughout the entire run on both runs.

The dyno's went like this:

Run 1: 351rwhp 348 rwtq
Run 2: 356rwhp 354 rwtq

[TheDastardlyDuo]

The last bone stock C5 Z06 I saw on the dyno had an average AFR of 12.3:1. It's leanest poing was 12.6:1, and the richest was 11.8:1. The car was completely untouched, and had only 7800 miles on it.

[Bad Habit Z]

So is the MAF (lb/min) supposed to jump around like that at WOT?