Cruise/Light Throttle AFR questions with Big Cam

[Nick912]

My current setup is a 2011 M6 Camaro ls3, with stock unported heads, LTH, CAI, 235/248 111LSA 109.5ICL cam (19.5* overlap at .050). Before purchasing hptuners, when my "tuner" finished with my car, WOT was great as was expected, but car drove terribly everywhere else (VVE table was untouched, and MAF was still set to be used at 4k rpm). After dialing in the VVE and disabling MAF, drivability was still pretty terrible (bucking and surging everywhere below 2.5k). After trying infinite changes to spark tables and basically anything else most commonly used to tame big cams, i found the only thing to get it driving well was to command around 13.5 in open loop everywhere. That is where I am at now, 02's disabled and staying in full time open loop/speed density, targeting .926 Lambda at everything besides WOT. Car drives factory smooth at 1200-1300, super unhappy at 1500-1600, and slight surging from 1600-2000. Besides slight fuel mileage differences, is there any negatives to running this rich all the time (Car is my DD for the time being). Also, I've been having issues chasing my tail with lean and rich spots in the VVE table, as you can see from the step log I am on. I changed map and rpm zone boundaries to make more sense, but all that did was change where the lean/rich spots were. I am not sure if my slightly off VVE table or transient fueling is causing my rich tip out an lean tip in (sometimes rich tip in as well, just depends on my car's mood). If anyone can answer my first question, or look over my tune/log and give me pointers to help answer my other questions, I would be extremely grateful. Happy New Year everyone!

VVE tuning step 25.hplAZ starting tune.hpt

[07GTS]

ur adaptive spark is way too aggressive -+ 15 deg for anything outside zero error will just cause issues ur seeing even going back to stock should be better then lower that to smooth it out, VVE needs work should be much smoother, if ur staying VVE then zero the predictive coefficients base, current, old, corrected tables, and zero out the maf table so its not affecting anything just leave 12g/s in the zero cell, also engine diag, airflow set the test ert min to 0 and high/low counts to 0, need to log idle adaptive spark, engine torque, dynamic air

[Nick912]

ur adaptive spark is way too aggressive -+ 15 deg for anything outside zero error will just cause issues ur seeing even going back to stock should be better then lower that to smooth it out, VVE needs work should be much smoother, if ur staying VVE then zero the predictive coefficients base, current, old, corrected tables, and zero out the maf table so its not affecting anything just leave 12g/s in the zero cell, also engine diag, airflow set the test ert min to 0 and high/low counts to 0, need to log idle adaptive spark, engine torque, dynamic air

Sounds good. I have done 25 30+ minute drives logging EQ error and making changes to the VVE (usually multiply by % half), and it seems to take on the same weird shape every time. No matter how much I changed zone boundaries or whatnot, I've had no luck getting the VVE smooth. I'm hoping zeroing out the VVE tables you mentioned will help. I have never looked at those tables myself, can you explain to me what these do by chance? If that one change is able to get me going in the right direction, I really owe you one Also for the idle adaptive, the massive spark swings help the cam's chop pattern sound more predictable and healthy, my ocd can't handle the stumble-y idle I get with reasonable numbers in those tables. I will definitely change them back if I see erratic spark anywhere in the future though. Also, which table are you referring to where you stated to leave 12g/s in at?

[07GTS]

aah u want the bap, bap, bap, bap idle sound, just remember that those tables gear/coastdown are used when driving also so will cause the sawtooth ur getting causing the issues, the 12g/s in the zero cell of the maf table then zero out the rest so it dosnt come into play with readings in scanner, with the zones in the vve make them all as equal as u can over the area u are using map/rpm that way it will calculate it smoother, and do a test after u change boundaries also make a change and calculate as some can make zone errors so u have to then adjust it to a different row or column, if ur VVE only u dont need the predictions for the maf/vve blend so can zero those out encase they are still active when they dont need to be

[Nick912]

aah u want the bap, bap, bap, bap idle sound, just remember that those tables gear/coastdown are used when driving also so will cause the sawtooth ur getting causing the issues, the 12g/s in the zero cell of the maf table then zero out the rest so it dosnt come into play with readings in scanner, with the zones in the vve make them all as equal as u can over the area u are using map/rpm that way it will calculate it smoother, and do a test after u change boundaries also make a change and calculate as some can make zone errors so u have to then adjust it to a different row or column, if ur VVE only u dont need the predictions for the maf/vve blend so can zero those out encase they are still active when they dont need to be

Thanks man, all great info. I made the zones equal everywhere, rather than focusing on getting better resolution in my problem areas. Moving company is taking my car tomorrow morning, I'll go see if I can make some last minute changes. Hopefully the better weather in Arizona vs Illinois will make it easier to dial everything in (WOT runs with icy roads and radials isn't very fun). Last question for ya, is there an issue with running the car rich? I'm just a little worried about fouling plugs running the car at 13.5, as I put 50 miles on it a day or so. Thanks for all the help!

[07GTS]

it prob will build up some on the pistons over time being little richer as its not a equal burn or use e10 will burn little cleaner but can build up anyway if it just cruises around all its life so bit if a rev now and then will help, if u play round with it u should be able to run at stoich just takes time to get all the tables to work together, also with EOIT set the 0-1024rpm cells to 520, then 6144rpm and up to 580 and populate from the 520 to 580 values, then set the normal ect table highlight all and remove 30 then the normal rpm set to all zeros, that may make fuel little richer so just remove to correct

[Nick912]

Everything around me is e10 most of the time I think. I try thinking in Lambda bc our fuel here in Illinois constantly changes from winter to summer blends. I populated the eoit worksheet I always use with my cam info and the numbers you gave me. It looks like it makes sense visually. I also changed zone values and posted in old VVE table, looks much smoother. Time to dial it in again and see if everything works together nicely. If anyone has the time to give me a sanity check and make sure my new VVE zones make more sense than before, it would be appreciated.

Eoit changes.xlsxVVE tuning step 28.hpt

[07GTS]

try this one i just set the boundaries and put your table back in and calculated stays almost as is

[Nick912]

I'll give it a go, thanks so much for all the help man.

[Nick912]

try this one i just set the boundaries and put your table back in and calculated stays almost as is

Car is currently being shipped as of now, but using those smoother VVE boundaries gave me great drivability from 1000-1500. After a bunch of logging, I have a lean spot at 1800 and 2600 (I've read a thread with others having an identical issue). When giving the engine the fueling it wants and adding in the necessary fuel at those rpm's, I was able to get EQ error closer, but drivability declined. I never had good luck with the dyno tune I had that was running a blended setup(although the VVE was untouched which was probably a larger issue), so I have been running VVE only hoping to clean up drivability. With the cam specs provided above, does anybody have any suggestions to get the best 1200-2000 rpm drivability? I'll post a pic of the VVE table and logged error for the table that gave me good drivability (first 2 pics) and post the table that got rid of lean spots (Not totally dialed in, but getting closer, yet losing drivability). If anyone thinks running a blended maf setup would help drivability, and could give me a good spot to bring in MAF considering my cam choice, I would greatly appreciate it. I've been spending a few hours a day for the last month or so trying to get the car to behave enough to drive, I really need y'all help to get me to the other side.

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[hjtrbo]

07GTS is awesome!

My setup is a blended tune with dynamic high rpm disable at 1800 and re-enable at 1600. No problems, maybe try that.

[Nick912]

07GTS is awesome!

My setup is a blended tune with dynamic high rpm disable at 1800 and re-enable at 1600. No problems, maybe try that.

I agree! I finally have drivability decent in certain spots, super close to putting the laptop down and finally enjoying the car because of his help. Ill try out re-enabling the maf and running a blended tune. Can't wait till I have the funds together to ditch the manual and do a 4l80e swap. A converter would definitely be more forgiving of my tuning abilities than this damn 6 puck

[07GTS]

is your 1800-2600 spot a throttle spot so it may need some transient fueling adjustments to fix the lean or is it lean just lightly going thru that area ? if ur sitting steady in those areas and fuel is good then id look at the transient areas to help

[Nick912]

Update on the thread: got annoyed and decided to try MAF only for the first time, and I have been pleasantly surprised. Drives exactly how I wanted it too, 1700rpm and above smooth as butter, also smooth down to 1200 in 6th. Took under an hour to get it dialed in +/- 1%. Also MAF is probably the better option bc of the major temperature swings out here in the desert. Thanks for the help everyone. I think I'll hold off on the VVE stuff until I exceed the MAF

[Nick912]

Does anyone know how the ECM handles MAF/VVE on a blended setup? As stated above, I have drivability good past 1700 rpms or so, and I would like to use the VVE everywhere below that (as I'm fairly certain the MAF isn't getting great data down there due to reversion or whatnot). I would like to set my VVE boundaries to allow extreme clarity in this place, and from 1700+ only have one large rpm zone. Does the ECM look at the VVE table above the filtered MAF setpoint at all for any reason, such as large transients? If so, I would think that this wouldn't be the greatest idea.

[LSandlteditor]

Does anyone know how the ECM handles MAF/VVE on a blended setup? As stated above, I have drivability good past 1700 rpms or so, and I would like to use the VVE everywhere below that (as I'm fairly certain the MAF isn't getting great data down there due to reversion or whatnot). I would like to set my VVE boundaries to allow extreme clarity in this place, and from 1700+ only have one large rpm zone. Does the ECM look at the VVE table above the filtered MAF setpoint at all for any reason, such as large transients? If so, I would think that this wouldn't be the greatest idea.

VVE operates and takes over when there is "instable conditions" such as transients, quick stop, traffic, stop and go...