I've been in the process of tuning my 2011 Malibu in an effort to learn how to use the software. I've read the book by Greg Banish and scoured these forums before even touching the stock tune.
DCFO, cot, and timing -5 degrees.
Histogram cell hits 30
I had the tune setup for MAF open loop with a wideband, histogram reading out in EQ err on the same Hz scale in the tune. I got that dialed in to +/-2% err.
I moved onto the VVE using OLSD (MAF failed, see and mil on) with EQ err plotted against MAP/RPM and got everything running rich by eliminating all the 2%+ lean spots.
I moved back to MAF. Got everything back down to +/-2% err. Then moved back to VVE.
I am also filtering out transients using Cringer's filters:
CL: [2517.161.avg(1500)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(1500)])+abs([50090.156.slope(-500)]))<2 and ([6310]=9 OR [6310]=14 OR [6310]=15)=0
PE: [2517.161.avg(1500)]=0 and [2517.161.avg(-200)]=0 and (abs([50090.156.slope(250)])+abs([50090.156.slope(-250)]))<2 and [6310.avg(250)]=9
The problem I'm having is that there are zones that refuse to come close to one another with +6% in one cell and -8% in another. I will sit there iterating and iterating with Cringer's VVE assistant software only to be faced with that cell out of whack.
I'm really hoping someone can point out something I'm doing wrong.
Something else to note is that I tried Cringer's method for closed loop tuning and after running a log everything was hellaciously rich in the VVE histogram according to the narrowband and wideband. I don't know if I should try that and see where it lands.
I have attached a tune and the following iterations and a log from the first tune below. I can't figure out how to upload the other log files, I think they may be too large?
See this thread starting at post #164 https://forum.hptuners.com/showthrea...for-gen4/page9. A few guys are just dialing in the MAF and then adjusting the VVE table such that "VE Airflow" matches MAF - no fancy formulas or filtering necessarily.
Also, not sure if your ECU acts like mine (don't have HPTuners on this computer), but in my case and in several others you can only adjust the base VVE table directly, where the cams are set to 0 degrees. If that's the case you'll want to set your cams to 0 so that the VE Airflow you see reflects the base table. Once the base table is dialed in then you can set your cams back to where you want, and then to adjust the other VVE table(s) for those cam positions you'll have to adjust the coefficients directly. See my thread post #11 https://forum.hptuners.com/showthrea...tor-Dwell-Time for some info. I made a calculator in Excel to figure out what the coefficients need to be to get a desired value in the VVE table; the coefficients are for a given zone so I just pick a cell near the centre of the zone to adjust since changing the coefficients will affect the whole zone (i.e. you don't have to change every individual cell, so it's not toooo tedious). Haven't used Cringer's tool but maybe it makes this part easier than using my Excel calculator.
I also dial in the MAF and VVE at the same time. I've heard some saying that they dial in the MAF and VVE separately, car runs great in either case, but then when both are active ("blended") the car runs like crap. I tuned them both at the same time and the car runs great. May just want to consider doing that as there is really no reason to adjust them individually as far as I know, at least on the Gen IV and V ECU's. I also leave COT on to protect the cats (only see it come on when I'm running steady at 4000+ RPM) and it's easy to filter out if it does occur. I kept spark timing factory as well just in case it affects fueling, because if it does then you'll be readjusting everything again once you finally get it all dialed in.
As for zones not cooperating, I get this too in a couple zones. Not much you can do about it so long as the data you're getting is correct. I found the best way to dial in the VVE is to go for a long (an hour or so) trip on a non-busy highway and just go through different speeds in different gears with cruise control set; I'll do 100 km/h to 130 km/h in 5 km/h increments, doing each in 6th gear, 5th, 4th, 3rd for about a minute or two each. After an hour or less I have data for 1600 RPM to over 4000 RPM and 0.32 to 1.00 pressure ratio (all zones except the top row and left column, so the zones where I actually drive). Still working on it but after two trips everything is within 4%, most cells within 2%. And you don't need to do a whole lot of filtering, really just need to filter out the gear changes and COT if it comes on.
I didn't know to lock out the cams either - even after spending who knows how many 100's of hours reading the forums I didn't see one post mentioning to do so, but one day it just came to me (and this was even months after figuring out how to manipulate the cam coefficients... ... didn't put 2 and 2 together). Note that the engine will probably feel sluggish, either at the low end or high end depending on how your cams work. In the case of the LFX, with both cams at 0 it runs pretty slow and crappy at first and after 5000 RPM or so it starts to pick up (don't really notice when driving normally but if doing a WOT pull you'll notice).
For the zones you don't hit normally while driving, which for me is below 1600 RPM and 0.32 ratio, I basically just copied/pasted the 1600 column and 0.32 row to the 1400 RPM column and 0.30 row, multiplied by 0.99, then interpolated from the lowest RPM and ratio - maybe not the best way to do it but as mentioned the car runs/accelerates as smooth as stock. Just found it difficult to hit those areas driving normally and would sometimes see my wideband go like 8% lean at 1400 RPM meanwhile 1600 was almost dead on 1.00. Guessing intake reversion (air going back through the MAF sensor and being counted twice). After messing around trying to hit these zones I just interpolated and everything seems fine. meh. The idle cells can of course been tuned like normal.
I found a setting under Airflow<Variable Camshaft for enable/disable oils temps for the VVT camshafts. I cranked them up and drove around while glancing at the intake/exhaust cam angles and they didn't go above 0.0. I'm going to run some logs n tune from them and see where I land.
Seriously dude, I appreciate your replies. I've been banging my head on the same wall for over a month. Hopefully this lets me ice my head while making some progress on this car.
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... didn't put 2 and 2 together). Note that the engine will probably feel sluggish, either at the low end or high end depending on how your cams work. In the case of the LFX, with both cams at 0 it runs pretty slow and crappy at first and after 5000 RPM or so it starts to pick up (don't really notice when driving normally but if doing a WOT pull you'll notice).