2011 CTS V - Help with this VVE ridge at 2600 RPM

[Critter93]

Alrighty Tuning Gurus,

I have been dialing in the VVE table on my 2011 CTS-V (mods below). I am able to get everything pretty much dialed in except for this ridge that appears at 2600 RPM. Attached is the tune and latest log. Any help would be greatly appreciated. Once I have this table fixed I will re-attack the MAF and then chase down the lean tip in at low RPM when the engine is cold....if it is still there.

Justin
2011 CTS-V
Griptec 2.38 Pulley
TSP Long tube headers and exhaust (with high flow cats) to stock mufflers
ID1050x injectors
AirRaid CAI
C&R Heat Exchanger
BMR under hood reservoir
Flex Fuel Kit

Caddy - SD Step 12.hpt2011 CTS-V - Pulley Headers CAI ID1050x.hpl

[sgod1100]

welcome to the party pal.....lol. I noticed this years ago with no real solution. Get your reading glasses on if you like to read all of the things that me and many others have tried. There's also a ridge around 1600 rpms too.

https://forum.hptuners.com/showthrea...rpms-2014-ctsv

[sgod1100]

Alrighty Tuning Gurus,

I have been dialing in the VVE table on my 2011 CTS-V (mods below). I am able to get everything pretty much dialed in except for this ridge that appears at 2600 RPM. Attached is the tune and latest log. Any help would be greatly appreciated. Once I have this table fixed I will re-attack the MAF and then chase down the lean tip in at low RPM when the engine is cold....if it is still there.

Justin
2011 CTS-V
Griptec 2.38 Pulley
TSP Long tube headers and exhaust (with high flow cats) to stock mufflers
ID1050x injectors
AirRaid CAI
C&R Heat Exchanger
BMR under hood reservoir
Flex Fuel Kit

Caddy - SD Step 12.hpt2011 CTS-V - Pulley Headers CAI ID1050x.hpl

From my experience you will be better off adding fueling via the maf vs. the VVE table (assuming you are running an OEM style "blended" tune). In my experience I've added ALOT of fuel in those areas on the VVE table with little change, since the VVE is really a back-up to the maf. No need to unplug the maf (if that's what you did) you can just disable it via the tune.

Also looks like you are running OL, any reason why? You can use your NB O2 sensors to tune your part throttle tuning versus using your WB especially if you are going to reenable your NBs to make the corrections. Just use your WB for WOT/PE areas

[Critter93]

Thanks man, I appreciate it.

Gives me the good vibes that I did it right. I have had the car at two different tuners since getting it and haven't been happy with either. I have the time now to spend on getting it all dialed in right before the next set of mods I hope to make during the next year.

[Critter93]

I was just using the WB for all the adjustment. I do plan on running the OEM style blended tune as I think it will help with overall drive ability (would still like it to pass the wife test). About to kick the MAF back on and retune that before I go ahead turn the fuel trims back on. The goal is to make it run like it came from the factory with all the extra power....anything less really isn't worth it. On a side note, I really hate the VVE crap and all the extra stuff on the Gen 4 ECUs. Tuned my buddies 1999 Trans Am with a very healthy cam and all the bolt ons and the thing runs bloody awesome.

[edcmat-l1]

Turn closed loop back on and use the trims to dial in anything idle and part throttle. Leave the wideband for WOT.

[Critter93]

Closed loop back on. Gonna try some more WOT runs to make sure I am good with the the VVE table and then on to the MAF again. It should be fairly close already but I want to make sure it is dialed in.

Thanks for chiming in!

[Alvin]

Alrighty Tuning Gurus,

I have been dialing in the VVE table on my 2011 CTS-V (mods below). I am able to get everything pretty much dialed in except for this ridge that appears at 2600 RPM. Attached is the tune and latest log. Any help would be greatly appreciated. Once I have this table fixed I will re-attack the MAF and then chase down the lean tip in at low RPM when the engine is cold....if it is still there.

Justin
2011 CTS-V
Griptec 2.38 Pulley
TSP Long tube headers and exhaust (with high flow cats) to stock mufflers
ID1050x injectors
AirRaid CAI
C&R Heat Exchanger
BMR under hood reservoir
Flex Fuel Kit

Caddy - SD Step 12.hpt2011 CTS-V - Pulley Headers CAI ID1050x.hpl

This ridge in your VVE table looks boundary zone induced... meaning when HPTuners calculates the VVE table it can't get it to fit properly in the zones setup in the tune. I can do the math on better zone boundaries that will likely make this VVE smooth.

Is that what you are after? I ask cause I don't mind doing it but I am a bit short of time. I don't mind if that is what you are after.

[Critter93]

Thanks for the offer! Don't worry about it though. If it affects the drivability down the road I will take another look but the drive home this morning was smooth as butter. Did some pulls and the VVE table looks pretty good even with the ridges. On to the MAF later this week.

[sgod1100]

[QUOTE=Critter93;781655]Thanks for the offer! Don't worry about it though. If it affects the drivability down the road I will take another look but the drive home this morning was smooth as butter. Did some pulls and the VVE table looks pretty good even with the ridges. On to the MAF later this week.[/QUOT

Not sure if you have an M6 trans or not, but when I first notice the two lean ridges I could feel the car slightly surge while I was accelerating from a standstill. My currently solution is adding fueling to the 5500-6000hz area of the maf to help with that area and I "raped" my PE table at the 2500 rpm spot to add fuel while i'm in OL.

[sgod1100]

This ridge in your VVE table looks boundary zone induced... meaning when HPTuners calculates the VVE table it can't get it to fit properly in the zones setup in the tune. I can do the math on better zone boundaries that will likely make this VVE smooth.

Is that what you are after? I ask cause I don't mind doing it but I am a bit short of time. I don't mind if that is what you are after.

I've actually tried changing my zone boundaries to have the 2600 rpm area in the middle of a zone versus the end and still had the same exact lean issue

[JayRolla]

This is close to how my VVE table ended up.

[Alvin]

I've actually tried changing my zone boundaries to have the 2600 rpm area in the middle of a zone versus the end and still had the same exact lean issue

It doesn't look like he has that peak intentionally.. like he's tuning for the lean spot you are seeing..

Rather it looks like the harsh boundary edges when the RPM/MAP boundary tables could use adjusting.

[GHuggins]

I'm tuning an ls9 in Europe right now doing this same thing. I really started looking out for it since Sgod's original posting on it. Only reason I bring it up is because the only mods to his are a pulley and cai and the exact same problem is present - 10% lean in those spots that are really evident with the original PE settings that keep it in CL too long. Only way I've found to help it or reduce it is to completely change the fpcm pressure settings - originally based off of the other gentleman's studies (I'm putting the pressures closer together) and injection timing to be more advanced through that area and before. I've even seen it on some NA cammed cars where it was just caused by those two things, but on them it was directly related to super overly large injector that were causing burn problems. Anyway, I just found it interesting how such a lightly modded car could have the same problem with a completely different cam, blower and so on... It has to be something burn or build related from GM...

[Critter93]

Thanks for all the input gents!

I wish I had just bought HPTuners in the beginning so I could have started tuning the stock engine and then made incremental changes as I modded everything. That way I could have seen where the mods started to affect the tune requirements.

I am glad to see that there are others who have these ridges and that their cars run out fine.

[sgod1100]

I'm tuning an ls9 in Europe right now doing this same thing. I really started looking out for it since Sgod's original posting on it. Only reason I bring it up is because the only mods to his are a pulley and cai and the exact same problem is present - 10% lean in those spots that are really evident with the original PE settings that keep it in CL too long. Only way I've found to help it or reduce it is to completely change the fpcm pressure settings - originally based off of the other gentleman's studies (I'm putting the pressures closer together) and injection timing to be more advanced through that area and before. I've even seen it on some NA cammed cars where it was just caused by those two things, but on them it was directly related to super overly large injector that were causing burn problems. Anyway, I just found it interesting how such a lightly modded car could have the same problem with a completely different cam, blower and so on... It has to be something burn or build related from GM...

It was L1FTD that was doing alot of testing with this and I THINK he was doing fpcm pressure testing as well. Is the LS9 you are tuning no longer have cats? After hearing that the issue was still present with stock injectors then that takes the spray pattern of the stock injectors out of the equation (Jayrolla was on stock injectors with headers if I recall correctly and still had the lean spots). I still wonder if it's something with disabling all of the DTCs that are all cat related.

[sgod1100]

Thanks for all the input gents!

I wish I had just bought HPTuners in the beginning so I could have started tuning the stock engine and then made incremental changes as I modded everything. That way I could have seen where the mods started to affect the tune requirements.

I am glad to see that there are others who have these ridges and that their cars run out fine.

that's exactly what I wished I would have done...lol. I put new injectors in AND removed my cats at the same time. After that is when I noticed those lean spots. And after hearing Jayrolla had them too after headers and STOCK injectors I was leaning more towards something cat removal related

[L1FTD]

It was L1FTD that was doing alot of testing with this and I THINK he was doing fpcm pressure testing as well. Is the LS9 you are tuning no longer have cats? After hearing that the issue was still present with stock injectors then that takes the spray pattern of the stock injectors out of the equation (Jayrolla was on stock injectors with headers if I recall correctly and still had the lean spots). I still wonder if it's something with disabling all of the DTCs that are all cat related.

Yes, definitely tested what GHuggins is talking about. Only thing I found to bring the lean spots down, besides adding more fuel.

The lower the fuel pressure, the richer 1600 & 2600 went, and everywhere else remained unchanged.

I gave up on that, to an extent. Lowered it down to 40psi, hit the throttle and pressure drops briefly to 30psi, and boost at 10+psi. End up being left with a 20psi delta and lean tip-in.

Definitely worked, but just a band-aid, and only helped WOT.

Theres another guy here with an LS9, has evidence of the same lean spots with a full factory exhaust and all o2 untouched.

Havent seen any evidence of non-factory supercharged cars doing this, seems to be only factory supercharged and still using factory FPCM.

Anyway Ive got nothing new to add, all the info is in sgod1100 lengthy thread.

[GHuggins]

Pulley and CAI are the only two mods on the ls9. I don't go any lower than about 50 to 55 psi with factory injectors and then make high pressure about 5 psi above that this way it blends better and is more like a regular pump setup. I also adjust the DC's. All this does is spread out the spray making it to where the fuel is a little better atomized and mixed better instead of possibly going out the exhaust, which shouldn't happen with a stock cam anyway, but nonetheless. I also adjust soi for it too. 10 degrees can make a big difference. Agreed that none of this is the solution. There's something going on with the factory setups to where they only work as "factory built" and why only certain cars "really" have the issue vs others is the better question...

[sgod1100]

This may have been done before, but has anyone tried a "write entire" vs. "write calibration"? I doubt this will do anything but.....