I do see you can adjust them under Engine>Airflow>Dynamic>Prediction Coefficients.Originally Posted by sgod1100
I do see you can adjust them under Engine>Airflow>Dynamic>Prediction Coefficients.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
Yeah, you can adjust them all you want, but actually dialing them in correctly for your specific setup is what i'm referring to. When they are left at the stock values you will not hit your commanded afr while being below the dyn air rpm cut-off, you will be lean. I've got logs showing just that
Zeroing the prediction coefficients definitely fixed some odd stuff on my LSA car.
I just zeroed them out and it had no change on our lean spike issue. But I was now getting a super rich spike at heavy to max throttle. Would richen to .65 EQ and then to my commanded .80 causing a major loss of power till it corrected. Added back the table data and issue fixed.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
I'm pretty sure there are more tables that work in unison to the prediction coefficients that we don't have access to. Instead of zeroing them I would suggest using other cals tables such as a ls9 or ls3's then testing. I futher don't believe these to be the problem - I'm sticking with a functionality or rationality check taking place that the bigger injectors are throwing off...
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
I looked at those and the LS9 are the same as the LSA. So I tried to zero them out to see what would happen and had a negative result. I somewhat have a slightly leaner EQ, by maybe .01-.02 than my commanded AFR before dynamic disable but nothing bad like sgod was referring too. Really strange the auto's dont seem to do it when in when TUTD is disabled.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
Yeah the prediction coefficients have no effect on our lean issue from my experience. I have had mine zero'd out and I've never ran into a super rich spike during heave accel.
I even discussed it with PGA2B where I wondered if the engineer writing the cal got lazy and didn't fix where the ctsv's didn't have the exhaust valves in the mufflers that would open and close to allow bypass like the ZL's do. Those on the ZL would open right around 2500 to 2800 rpms and if they were unplugged and not just unhooked via the vacuum line and capped off that way - they would go into some sort of weird reduced power mode and stumble right around that rpm area - might be why I've never noticed it as on every single one I tuned - unless it was a minor cai modded zl - I unhooked and capped off the vacuum line. So if said engineer got lazy and just threw the zL's cal into the ctsv - then that might explain some things. However I don't remember if you can technically read out the FULL calibration including the exhaust controls to see if it's active now or not? It should be in the chassis control module if it's like the newer stuff.
Just grasping at straws at this point as I'm almost positive it's a rationality check and something isn't working right.
Last edited by GHuggins; 05-26-2023 at 06:40 PM.
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
That's interesting.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
Sooooo. anyone else with an abnormally large brain have any other suggestions????
So the new injectors have the same issue I'm guessing. I've been poking around changing random stuff and nothing has an affect. I don't see what else we can try and it's driving me crazy.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
That's correct, same thing. Honestly not AS bad (I don't feel it as much which is good), but I can still see it on the logs. Yeah, me too.. drives me nuts as well
I decided to start my VVE table over fresh from stock and instead of tuning via wbo2 error I did the LTFT method. It didnt create the large spikes at 1600 and 2600 as much. It feels a lot better but I still see the lean spikes and can slightly feel them more depending on throttle percentage. Also ramping in PE faster helps for the harder throttles since it richens a lot quicker. I do notice if I am in like 6th gear on the highway and I hold it right at 2600rpms it does kind of stay pretty lean, jumping between 1.00 to 1.07 EQ ratio.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
If you are running a CL tune (which most of us are) you shouldn't be tuning the closed loop areas with the WB. WB should be used for OL only (as we don't have any other choice). Your NBs are going to be doing the corrections when you are driving around so you want use those (I like using STFT and have my LTFTs turned off). Yeah, if you are on the highway and go through that 2600 rpm zone it will have a long hump in the afr error graph.
Throwing out a thought because it seems similar and you are talking about the prediction coefficients now.
It could be something related to a max VE setting or something. The E40s have a table for that in dynamic airflow and it shows as a lean spot in the scanner if the table is not adjusted. Though with the later VVE stuff, they very well could have eliminated that type of thing entirely. Dynamic airflow has always been mapped out similar in hp tuners over many different GM vehicles but not the max VE table. So to me, it seems that the dynamic air calculation was an internal copy pasta at GM with inputs added or subtracted for various different vehicles.
The only thing I see in my tune (E67 Gen4) is "VE Correction factor" table under the Airflow> dynamic tab
Yeah that makes sense. That's how I normally did it. But I tried the wbo2 method to try and get those lean spots taken care of with some additional fuel which didn't do anything really. I might try and disable ltft then just use stft to see how that dials in the vve table but it does seem pretty good using ltft to adjust.
Last edited by JayRolla; 06-02-2023 at 11:17 AM.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
STFT go wayyy faster than LTFTs. Yeah, I had the same plan as you a few years ago-using the WB to see if I correct those lean areas, but it didn't work. Reason I have LTFTs off is because I don't want them to influence my WOT fueling. If you have a "+" LTFT prior to going into WOT/PE that percentage will be added to your PE fueling. Won't be much if you have your tuned dialed in, but I'm OCD..lol
Thats why I always shoot for negative fuel trims slightly. If something goes crazy and they go super lean without me knowing at least it will be safe and add fuel to PE. I sent another email to White just in case he overlooked my 1st email. I think I saw he just had a baby so he might just be taking some time off right now.
2013 CTS-V Coupe M6 - 1 7/8" Headers, 3" x-pipe, stock mufflers, Airaid intake w/green filter, ID1050X injectors, DSXtuning flex fuel kit, DMS under hood tank, upgraded pump, 3/4" lines, griptec 2.4" pulley, solid isolator, 100mm idler, reinforced brick, MM mild catch can, AEM 30-0334 wbo2, 600whp/630wtq
ok, cool. Hopefully he will get back to you sooner than later
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