07 Cobalt SS Data Logging Help

Hey guys. I've done some initial data logging (on a DynoJet dyno I should mention) on a 07 Cobalt SS with a stage 3 ZZP kit. A couple of things that initially concerned me:

the TPS is not making it to 88% on all the runs at WOT. I'm guessing it could just be dirty?

The injector duty cycle seems really low for 60lb injectors. 29% is the highest i've seen. I have an external Wideband moduel with the Dynojet and its reading 11.7 to 12 afr at WOT so that seems ok, but i've seen others with similar setups with their duty cycle well over 50% so i'm very concerned.

The fuel trims are not making sense. There's a bunch of areas in the STFT that are showing lean, but LTFT shows no positive values. Whats going on here?

I've attached the file for you all to have a look at. Thanks in advance!

TPS went up to 88% after 5k. Are you sure you're 100% all the way down. You're not logging iat2 or maf hz - add those unless your ve only. You're probably using the wrong IDC calculation pid i bet because at 6000rpm at 10.5 injector pulse is 52.6% duty cycle so either take what it says and double it or change the pid. Are you maf only, ve only or blend? Your idle is extremely rich and needs to be addressed however a log like this doesn't help for trim tuning because your doing pulls which will skew cells so if your trying to get idle and part throttle dialed in lay off the wot pulls and drive normally around as you would to get good data. Posting a tune file also helps more to see whats going on as well

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Originally Posted by TCSS07

TPS went up to 88% after 5k. Are you sure you're 100% all the way down. You're not logging iat2 or maf hz - add those unless your ve only. You're probably using the wrong IDC calculation pid i bet because at 6000rpm at 10.5 injector pulse is 52.6% duty cycle so either take what it says and double it or change the pid. Are you maf only, ve only or blend? Your idle is extremely rich and needs to be addressed however a log like this doesn't help for trim tuning because your doing pulls which will skew cells so if your trying to get idle and part throttle dialed in lay off the wot pulls and drive normally around as you would to get good data. Posting a tune file also helps more to see whats going on as well

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Hey I appreciate the reply. I plan on doing some more logs this afternoon. My friend was driving, so i'll make sure he has it right to the floor today.

I've done mostly dodge tunes in the past, so MAF tuning is a bit new to me. I will add IAT2 and MAF hz to my next log. I've read some posts on plotting MAF error using STFT+LTFT but i'm not quite sure how to set that up on the histogram.

I've attached the tune file for you to have a look at. Thanks

here are my layout and channels config - and before you should always have iat2 logging, sorry i didn't explain that well
Attachment 91757
Attachment 91758

You are in blend mode which is fine when the car is tuned in maf and ve by themselves but you cant make proper fueling adjustments in blend mode to the maf or ve because both charts are being used so the data wont be correct. You need to be is each mode standalone.

Quote:

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Originally Posted by TCSS07

here are my layout and channels config - and before you should always have iat2 logging, sorry i didn't explain that well
Attachment 91757
Attachment 91758

You are in blend mode which is fine when the car is tuned in maf and ve by themselves but you cant make proper fueling adjustments in blend mode to the maf or ve because both charts are being used so the data wont be correct. You need to be is each mode standalone.

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I appreciate the channels and layout. Very impressive! I guess i've got some reading to do on tuning each individually. Again, I appreciate the help.

So i've done a lot of reading and video watching over the last 24 hours and i've got a much deeper understanding of the LSJ tuning process. I had the car on the road today with MAF and DFCO disabled and I smoothed out the PE EQ table. I drove for about 30-40 minutes trying to capture as much as I could at 5000rpm and under.

I've posted the log and tune I used below

From what i've gathered, I take the data from the VE-LTFT histogram and and "Paste Special %" into the VE table. Smooth it, save it, upload it to the car and do another log. Rinse and repeat.

If i'm WAY off let me know!

Thanks
Attachment 91785
Attachment 91786

after a flash you should re-connect the scanner. once connected go to the user i/o command section and manually reset the fuel trims before making the newest log recording.

I went ahead and made some adjustments to the VE table based on the VE-LTFT histogram in my previous post. I reset LTFT in the scanner and did another drive. I saw some minor improvements up to 60kpa, but looks to have gotten worse higher up. I also noticed the STFT swings wildly from positive to negative.

If anyone with more knowledge than me could have a look at this it would be much appreciated. For some reason the log was cutting in and out so the file is choppy

Attachment 91804
Attachment 91805

Quote:

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Originally Posted by cobaltssoverbooster

after a flash you should re-connect the scanner. once connected go to the user i/o command section and manually reset the fuel trims before making the newest log recording.

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Thanks. I watched a few of your videos today and I did do that on the last run. I just posted above with my first attempt at VE tuning

your pulling quite a bit of fuel on the trims system. highlight your whole ve table and remove 15% ( so multiple the whole ve table by 0.85) reset trims and start again.
do you have a wideband? you cant tune wot without one and it just makes everything simpler.

Quote:

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Originally Posted by cobaltssoverbooster

your pulling quite a bit of fuel on the trims system. highlight your whole ve table and remove 15% ( so multiple the whole ve table by 0.85) reset trims and start again.
do you have a wideband? you cant tune wot without one and it just makes everything simpler.

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ok great i'll try that as a new starting point! Is it normal for the STFT to be that erratic?

I have a DynoJet dyno with the AFR module. I'm fairly certain there's a way to connect it via the prolink so I can view the data on the hptuners scanner, but I haven't quite figured it out yet.

Thanks a lot for the reply. I really appreciate it