Still looking for input on this. Anyone have clues on why the car transitions so badly at 2.5k? The torque/torque inverse was a great start but more info on how to catalog the data would be great. Currently the car is down with a charging fault, which I suspect is driving the idle issue. but not the 2.5k flutter. The tuning didn't cause the charging issue - it popped up in the past couple days but I think the idle hunt is symptomatic of the alternator dying, perhaps? That goes back to the early hard over speed surges that drove getting HP tuners to untangle the tune file. which is much improved - Getting there! I also still haven't heard back from support on the Indicated torque reference PID being added to the scanner. None of the other PIDS will really identify the information I need without going to a Dyno... which is on the to do list. Just gotta wait til I get some resources to sort out the Charging issue so the car runs without codes/service messages.
OK... after chasing several unrelated gremlins I've got a log, the tune and a adjusted tune I'm sorting in hopes it solves the 2.5k-3k stumble at part throttle. Can someone spot check this before I go for a drive, please? Logged for indicated torque. Bumped IPC to cover that. then adjusted Torque and inverse torque to match.
Took a drive and that didn't do anything for the issue. Here's the log. Notice that right at 2500 rpm & 70% load the ETC error goes to +10*, which demonstrates why there is the lean out condition. But not sure how to smooth that out.
I used this layout on your first log to look at where most of your torque error starts. to me it looks like MP 4-9, 3000rpms and above, .5 load and above.
that corresponds. I laid the 3rd file over this and it had only one hit on MP8, tho I didn't drive much because the etc error event happened again. Whats the best way to use this information? I'm going to try resetting the driver demand to stock and see if that smooths the etc error.
You can lower the cell hits required and see more data, you just start to see the extreme outlying data as well.
Putting the driver demand back to stock may help. Im looking at where you have pedal pos WOT start. I don't think that is necessary to have it that low. In your next log can you get ETC effective area?
I just got back on the driver demand. It made it worse - just a nasty nasty wall at 70% and 2500rpm that goes away if you stomp to WOT. I'll run another with the file from torqtest3 with effective area mapped.
I'll try another log tomorrow with both the stock driver demand and torque adjusted like this one, if I have time after autocross. here's the log with the effective area mapped. So if the etc error at 2500 isn't torque or driver demand... what's next to try?
This is what your predicted throttle angle vs ETC error looks like. I see a lot of error right at mid throttle just when it should be going into boost. Higher and lower throttle looks good. Basically you need to tell the throttle body model that it can reach these vacuum levels sooner with less effective throttle. This is due to the supercharger starting to force more air in than NA at those throttle angles. higher than those numbers the speed density/ Maf should take over and from what you say WOT is fine so no need to worry about that. Comparing NA tunes to supercharged tunes you can see the bump at lower vacuum/lower effective area in the predicted throttle angle.
What I'm hearing is that the tables need to move to the right so that there's less throttle right as it crosses 0 in hg, yes? is there a way to use the image you posted to apply to the chart? This is one of those inverse equations for the other table, yes?
Because it is an inverse relationship table you would apply what I posted to the effective area table as a %. Im working on a spreadsheet to build a new predicted throttle table from that.
OK, that's what I inferred - it's a percentage. So 15.5 becomes lower by 15%. I'm going to take it easy and start at 6% since that's the average of the whole column.
I think you went the wrong way. less effective area will result in less vacuum because of the increase in airflow is what you want. Also that is 15.5* of angle error so 15.5*/83*=18.6%. Starting with smaller % changes is fine tho until you find what helps.
sorry didn't see the edited x axis. This may help.
Hmmm. alright, I'll post up two files. One I added 20% and one I subtracted 20%. then renormalized and inversed each. let me know which one is in line with your thoughts? I think we want the one that I removed angle from? I'll catch up with this tomorrow afternoon after autocross.
Alright! this is going someplace positive. Took a semi long drive with idle at the front end. Still have a wandering idle but look at how much nicer the etc error is. the car pulls smooth at part throttle from 2500-4000 every time regardless of speed, load or gear. with only a slight hang right at 2500 which I think is fine tuning. Here's the file and log. This is like 100% better and looks like a little finese will get the rest of it. any comments on how to proceed next?
I just posted in the other thread. It looks like you are having the same idle surging issue with a supercharger. I believe it is caused by the ETC idle throttle angle vs airflow table. you should be able to correct this table using desired airmass from torque source, mass airflow, and ETC error. Another member mentioned a table that I have not seen before, Int. Time underspeed, and said that setting it to 1 helped. I see it in yours you could try that. It was under the same table so I believe fixing the throttle error in the table with fix this surging.
I used this layout and math parameter setup to log your ETC error and figure out where you needed modification. You may need to modify it to your new Axis's. Also ETC error/ 83 will give you the percent you should modify the table by. Then like you said just fine tuning it.
I actually have ETC vacuum as a existing PID from the scanner so I built my histogram around that. I set the int.time underspeed to 1 and reshaped the idle air mass/throttle angle. Going to take a drive and see what it does.
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