I'm workin on it!I know there is supposed to be a way to back calculate the ve table straight off the maf and then I think there's even a way to get both the maf and the ve table straight off of calculations.
I think I have it working, I just need to throw the calibration way off on mine to see if it works.
Post a log and tune if you want help
VCM Suite V3+ GETTING STARTED THREADS / HOW TO's
Tuner by night
CPX Tuning
2005 Corvette, M6
ECS 1500 Supercharger
AlkyControl Meth, Monster LT1-S Twin, NT05R's
ID1000's, 220/240, .598/.598, 118 from Cam Motion
2007 Escalade, A6
Stock
That would be so awesome. Plz share if you do have it working!
There are multiple ways to back calculate the VE values.
This one is the uncorrected equation =([PID.2126.KEL]*[PID.6210.MET]*[PID.6200]*[PID.6001])/[SENS.30.MET]
To make it work during tuning (when AFR target does NOT equal AFR measured) all you have to do in throw in the correction factor. From memory you can add * AFR measured/AFR target to the end of the equation and get the corrected GMVE values.
With the flooding over Xmas in North Alabama I haven't had much chance to play with the tune and prediction coefficients. Here is a better example of the problem.
2015-12-29.png
Notice how the MAF Cyl Air numbers are very different from the VE Cyl Air and Cyl Air numbers (ignore Fuel Cyl Air - I mistakenly gave Keith the equation for Fuel based GMVE NOT the Fuel Cyl Air I intended - I noted it in the scanner thread). This caused the engine to go waaaaaay lean and knock. It almost died as I let the clutch out so the controller added a ton of throttle to keep it running. So not typical operating conditions but indicative of the issues I am seeing with the prediction coefficients.
Do you still have to even do a correction if you're using the actual WB AFR instead of commanded? Seems like if you know how much fuel is going in (IFR x IPW) and you know what the actual AFR out the exhaust is.. then you should be able to figure out how much air is going in and thus what the VE or GMVE value is under those conditions.
IFR*IPW*AFRwb=GMVE*MAP/TEMP is what I saw on Marvin's site
You are absolutely correct. I tend to set up my logging parameters to work in both open and closed loop (therefore with WB active and with it inactive). Including the commanded term let's me take a look at where it was vice where I wanted it to be very easily. Comes in handy when you are going into PE as well (I do understand that the controller is not using the SD settings for PE but the engine still has a VE. This approach let's you look at the VE while in enrichment and can give insight into what the VE contour looks like - however you have to take it with a LARGE grain of salt).
Not sure I understand what you're saying here. When running 100% SD then it's using VE/SD tables for airflow calcs regardless of it being in PEOriginally Posted by sssnake
I have started playing with the prediction coefficients based on this thread http://www.hptuners.com/forum/showth...n-Coefficients which I know several of you were active in. I will say that it is making a positive difference but so far not enough of one. The swing to lean or rich when accelerating or decelerating rapidly is not as bad but I am seeing a couple of spots where the GMVE and MAF indicate more cyl air than the reported cyl air value. In that instance I get knock. Like I said better but not good enough. Right now I am basically using .9, .1, and 0 for base, current, and old. The corrected table is following BlueCat's recommendation. I am still playing with these corrected values to see if they will offer a solution. If not, I want to take the base down and the current values up. I have not been able to come up with any rhyme or reason on the MAP and TPS correction values.
Are you sure it's not a transient fueling issue? Those settings have a huge impact on fueling during quick throttle changes (also matters during slower changes, but they are less noticeable)
Sorry I typically think in terms of blended operation. Most of the time you are in PE you have exceeded your high rpm disable threshold (unless you have a PD blower with stout pulley or have the disable set very high). Again, sorry for the imprecise comment I had another conversation going on during the post. To the grain of salt comment, there seems to be a shift in VE during PE with my car. I don't know if this is typical but that is what I have been seeing. It could be due to my limited data for VE during PE. Maybe it as something to do with these prediction coefficients. I don't know. Remember - AMATEUR.
Could be transient fueling. But I thought they would add during accel. What I am seeing the the cyl air derived from the MAF and from the VE table is higher than the reported cyl air value during hard accel. Again, I thought transient fueling would add fuel over the MAF and VE values during acceleration.
My impact factor is increased around 5% (LSA heads on LS2 block). The maximum mass is decreased to 1024 (this was based on website post recommendations but I am not sure why a reduction is beneficial). Delay is cut from 56 to 15 pulses (to respond more quickly to changes).
Last edited by sssnake; 12-30-2015 at 10:34 AM.
We're all amateurs, don't worry about that
Post a log and tune if you want help
VCM Suite V3+ GETTING STARTED THREADS / HOW TO's
Tuner by night
CPX Tuning
2005 Corvette, M6
ECS 1500 Supercharger
AlkyControl Meth, Monster LT1-S Twin, NT05R's
ID1000's, 220/240, .598/.598, 118 from Cam Motion
2007 Escalade, A6
Stock
Sssnake, you can rework the equation you've posted based off of Marcin's equation that Carson posted and come up with a very nice back calculating VE tool. It's gotten me withen 2 to 5 percent error the very first pass so far. I'm personally using commanded instead of actual air fuel and having really great success with it so far. It's my understanding after talking to Marcin that if you use commanded your injector data has to be pretty spot on... SO not a bad idea to check via error on top of everything.
And just from what I'm reading into on your problem. I've experienced PE and part throttle issues like yours before after installing a cam into a PD blower. Problem for me was incorrect injector data and settings. Reason why I insist on ID injectors now... Also why I use the injection timing methods that I do now too... You "might" be able to fix your problem with the transient fueling, but it sounds like a lot might be off and need to be "re-looked" at? What I've all but come to the conclusion on is as long as your injection data is correct, transients, predictions and nearly all idle proportional and integral tables will hardly need to be touched. So not sure on your injector situation, but might be something to think about?
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
GHuggins,
Thanks, for your comments. I did go with flow matched Deka shorty 60s. I thought they were fairly well known and characterized by Greg B's data set (which I am using). I do understand the IDs to be much better but the issues I am seeing seem to be in the commanded piece vice incorrect fuel delivery. The MAF and VE show one thing but cyl air shows something different. It is my understanding (I'm not saying I that I am not wrong) that the cyl air and/or dynamic airflow is what the controller uses for fueling commands. If this number is wrong, and mine appears to be, I'm not sure how more accurately characterized injectors would help. I am a newb but I am also an EE that has designed and built control systems and this appears to be a problem with the airflow/cyl air estimation to me. I mean AFR is not necessarily a complex thing once you accurately estimate the amount of air in the cylinder.
I forgot to mention that I am using a manifold referenced fuel system to get rid of some of the variability in the injector flow (one less variable). I would think this simplifies the injector portion substantially. I have checked the differential pressure across the injectors and it seems to be very consistent.
Hi Guys,
I've been dealing with knock issues as well on a LN2. I found the manual transmission was my issue. It would rattle terribly during off throttle or snapping the throttle open quick, pulling timing back to 8 degrees. I've had great luck with 28 degrees in the middle and add a couple for over rev to 30. I verified thru many of full pulls with no timing retards that 30 was fine, so I also lowered the max attack.
My build is a 1998 S10 2200 LN2 that I've decked to .001 and cut the head to a healthy 10.25 to 1 compression.
I'll get jumped on for this, but with the deka 60's I found it better "for who knows what reason" to input both the map and volt offset tables into the tune. I say for who knows what reason because technically it's only supposed to use one set of values regardless of there being both tables in the tune or not, but to me it "seemed" like it was "averaging" the data between the two maps. Fixed a lot of instabilities? I have no idea as to why?
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
^^^^^ Wow! Good to know. I will give it a shot.
I tried more sets of Deka injector data than I care to remember.. and even came up with my own a time or two using the Ford data found on the drawings for the injectors along with DSteck's injector data converter sheet.
Is there only one "Deka 60" injector? Or are there multiple that sell under (or rip off) that name?
I always thought there were multiple but who knows.
I never could get them to behave.. went to ID's and things got easier
Well i'll admit that some of this is going a bit over my head. But i grasp what sssnake is saying about the predictive airflow (at a high level)
I've been working on improving my VE table and during this I have been doing SD only and failing the MAF. This seems to have helped my knock and almost removed it completely. Most knock I have seen is maybe less than half a degree removed in one spot over several hours of log data( w/ my SD only / VVE specific tuning file flashed). This would seem to support ssnakes argument since my understanding is that the MAF data will not be referenced and in laymans terms the predictive coefficient crap and blended mode / hybrid crap is not happening.
Or i could have still just needed work on the VVE table as pointed out before, or perhaps the swings for the o2 sensors are still messing me up... What do i know, im still a greener tuner than most of you guys
new vve.png
Last edited by itsdaveonline; 12-31-2015 at 10:49 AM.
Read some of the prediction coefficient stuff in more detail. Some of the guys are disabling it all together. Has anyone in here with knock troubles tried to do this?
Do i literally just paste zero's directly into all of the coefficient tables? I'm tempted to try this along with my improved VE table in my "normal" tune and report back with knock results.
Last edited by itsdaveonline; 12-31-2015 at 11:33 AM.
There are some rip offs running around I believe.
The data the Greg Banish put out in his first CD cured so many of my problems I had on a Hahn turbo kit LSJ Cobalt I was tuning. I learned a good lesson on injectors with that car and now only insist on ID's or data I have from Greg's CD. Chasing your tail sucks.
Reply With Quote