2013 Chevy Sonic 1.4 tuning help

[Stew]

Hi all, I'm pretty new to tuning with software and from what I'm reading on the forums here I've jumped head first into the deep end starting with an E78 ECM. I get what most of the tables and values do but I'm still wrapping my head around how some of them interact with each other, and again reading the forums I don't think I'm alone, lol.

I've got two issues I need help with, I haven't posted my tune yet because I don't think it's going to come into play just yet. First problem is of course I'm not making enough boost. I started by slowly increasing some torque management and driver demand tables and was getting a small improvement, did some logging and increase a little more, log, etc. This got me closer to my goal but I was still far short.

Eventually I followed what Chris wrote in post 211 here:
http://www.hptuners.com/forum/showth...-Tuning/page11

But even after modifying all these exactly as outlined I still was only peaking around 17.5 PSI and it settles down around 15.5 PSI. So after this I went ahead and modified the map B and C driver demand tables just in case, as well as a couple other things I saw mentioned in other threads such as adjusting the Failure Air Mass to keep a similar relationship with the Turbo Overspeed Limit Min as before changing that per the thread mentioned above. I also massaged the Wastegate Open Boost table with no change in boost.

Even after all this I am still only peaking in the high 16's to low 17's PSI and settling in the mid 15's, I am obviously missing something here. Chris's modifications to the tables in the thread mentioned above are for a 2011 or 2012 Cruze, is there any chance that I need to look for something more in a 2013? Or is there any possibility the Sonic has different tables than the Cruze?

I am scratching my head on this one!

[Stew]

I've relaxed things a little more but for the life of me I cannot get higher than around 205 kPa. KR is virtually non existent, cyl airmass doesn't seem to get higher than .75, it's acting as if it's being limited but I just am not seeing where. And after the last relaxing of some tables there is a little oscillating when at the boost limit which you can observe in the log file but I'm not really worried about that for now.

[Stew]

The table which was limiting me was the Turbo Base DC, after increasing some of these values I was able to start commanding boost up to my limit. Actually, a little higher but now that that little mystery is solved I can start fine tuning.

[bherrick]

Good job!

[Stew]

Good job!

Thanks, I was glad when I finally figured that out!

Ran into another interesting interaction that I'm not quite following in this table:


The values showing in the table above are the ones that work fine, but I had lowered all the values except the value in the cell for ECT 140* thinking I wanted to restrict boost when the engine is still warming up. Well after making that change I could not get my 235 kPa that's listed in the right most cell, I was getting max around 195 kPa. This makes no sense to me, it seems like if no other tables were changed and as long as ECT is greater than 140* I should be commanding the full 235. Go figure.

[Cruze]

Thats an interesting one. Ive never messed with anything below 140. Just so the obvious is out of the way, the coolant temp was above 140?

[Stew]

Yep, I was definitely over 140*, and as soon as I flashed back to my previous tune prior to that one change everything was again working as expected. I mostly have some fine tuning left and it would be a little easier going if not for that kind of unexpected stuff, but we must be enjoying the process, right? Otherwise we would've just got a mail order tune and called it good!

Oh, and the second issue I mentioned in my first post but then didn't talk about was regarding logging. I must be doing something wrong there because when I am in the chart view and go to add a sensor for me to monitor, they don't seem to be working. I added the PID for boost sense and a couple others and I don't think any of the ones I added were reading data. They get added to the chart fine but that's about it.

[Cruze]

Unexpected things make me frustrated. No, idea why it would cause something like that.

You can add them to the chart but they wont populate unless the PID's are in the table first.

[Stew]

Cruze, I'm not sure I'm following you. In the scanner chart view I right click on the chart -> chart settings, click on one of the charts -> Add Series, click on the newly added series then you can choose a sensor or PID to monitor, I click on the PID section and simply select one of the many predefined PID's, in this case Engine -> Airflow -> Boost Pressure Sensor kPa. It sounds like I am leaving a step out?

On to the tune... One thing I'm trying to fine tune is boost. When doing a test run boost comes on very strong in lower gears like 1st, 2nd and 3rd but is slower to ramp up if I do a run starting in 4th, 5th and 6th. And in the lower gears it will spike a little past my max boost then settle on the max boost but then slowly taper off as I get north of 4000 rpm.

The main table effecting this seems to still be the Turbo Base DC but I am also looking at the Pressure Delta Factor. I know if I could figure out what I'm doing wrong adding some of these sensors to monitor it would be less trial and error since I'd have actual data to review.

[Matt M]

Thanks, I was glad when I finally figured that out!

Ran into another interesting interaction that I'm not quite following in this table:


The values showing in the table above are the ones that work fine, but I had lowered all the values except the value in the cell for ECT 140* thinking I wanted to restrict boost when the engine is still warming up. Well after making that change I could not get my 235 kPa that's listed in the right most cell, I was getting max around 195 kPa. This makes no sense to me, it seems like if no other tables were changed and as long as ECT is greater than 140* I should be commanding the full 235. Go figure.

I've run into that as well. It couple be mislabeled and supposed to read degrees C.

[Tre-Cool]

Even if its in degrees C, it would be well past 60c. Even the newer E83 has a similar table. So I might have a play with mine as I've also hit a boost limit.

It could be a Map-baro factor limiter?