AFRs

[pormgb]

Hi All,

I'm doing some tuning before the winter comes and I'm trying to get a handle on ideal AFRs. Since the temperature has dropped I'm experiencing some popping and hesitation when I go hard on the gas under 3K RPM, I've done a RAFIG + Calc VET. Her are some images of my AFRs, does this look normal?

Motor specs;
LS6 Block
Camshaft 226/229 .575/.578 116 LSA
LS6 Intake
85mm Professional Products Throttle Body
Hooker Headers
No Cats
Denso Iridium plugs gaped at 40


1219412195

[5.7ute]

Post your tune there is something majorly wrong there.
You do not appear to have commanded a rich enough AFR at high map (judging by a ben of 1.00 where 14.7 is the actual AFR)

[pormgb]

Post your tune there is something majorly wrong there.
You do not appear to have commanded a rich enough AFR at high map (judging by a ben of 1.00 where 14.7 is the actual AFR)

OK, I've attached my tune.

I've also been chasing some knock retard around 4k, I suspected i was running a bit lean.

Thanks!!

[Gregs]

wow ve table needs some help! why do you have the ve table jumping up like that after 4000 rpm?

[pormgb]

wow ve table needs some help! why do you have the ve table jumping up like that after 4000 rpm?
This is the VE table I've had for a while, I've done multiple Calc VETs so I suspected the table was OK.

[pormgb]

Update,

I just went through the below thread an I think I know whats going on;

http://forum.efilive.com/showthread.php?16618-PE-Mode-Controls-All-Closed-Loop-Fueling&highlight=b3618

I have been following the Calc VET tutorial including additional tips, I had B0120,B3618,B3605,B4205 setup incorrectly. I have returned those settings to stock and will test the car tomorrow, here is what I now have.

12199

[Tre-Cool]

that last tune you posted wouldnt help you in tuning the ve table as it would be in closed loop.

try this one.
12203

[pormgb]

that last tune you posted wouldnt help you in tuning the ve table as it would be in closed loop.

try this one.
12203

Ok, I took a look, can you explain the changes. Does this tune disable O2 sensors and use only MAF+VE?

Installed the new tune, car will idle but almost stall when revs try to return to normal, I need to readjust my idle parameters. Idle AFR reads around 13.9 to 14 when cold, Is this OK?

[n8dogg]

B3618 PE based on RPM, shows AFR set at 17.03? Very lean here, for 100% gas 12.5-12.7 would be ideal. The main VE does not look that bad, could use some more smoothing but in the WOT areas it shouldn't matter much.

[pormgb]

B3618 PE based on RPM, shows AFR set at 17.03? Very lean here, for 100% gas 12.5-12.7 would be ideal. The main VE does not look that bad, could use some more smoothing but in the WOT areas it shouldn't matter much.

I'm now running the then provided by Tre-Cool, it addresses B3618.

[Tre-Cool]

personally cold afr i'd like around 13.5~13.8 afr for a bit then lean out to stoich.

i wasnt sure how your current idle was with your cam so didnt change much but remove the throttle follower added airflow.

open up b4307 and add another 1.2 to the entire table and see how that goes.

ideally you would do a rafig, but with a cam your size at 90 degrees celcius i have had great results with around 13.2g/sec

to tune the ve table you need to be running in open loop for the entire table, personal preference here but i dont use the pe table in my own tunes, i prefer to command ratio via map pressure.

ideally you should switch over to a custom os and get rid of the maf entirely.

[pormgb]

personally cold afr i'd like around 13.5~13.8 afr for a bit then lean out to stoich.

i wasnt sure how your current idle was with your cam so didnt change much but remove the throttle follower added airflow.

open up b4307 and add another 1.2 to the entire table and see how that goes.

ideally you would do a rafig, but with a cam your size at 90 degrees celcius i have had great results with around 13.2g/sec

to tune the ve table you need to be running in open loop for the entire table, personal preference here but i dont use the pe table in my own tunes, i prefer to command ratio via map pressure.

ideally you should switch over to a custom os and get rid of the maf entirely.

This is great, I was planning to switch to open loop because I have a leak in my left header collector, I also have dual wide band's so I use the right side for Calc Vet.
Yes, I did suspect my idle problem was related to desired air flow, I copied a table from a ZO6 with a similar size cam, ill do a RAFIG today to clean it up.

[pormgb]

Took the car for a drive and done some logging, the car is running rich with lots of popping from the exhaust. Something is still not right, will a Calc VET provide the correct VE and AFRs? I've also attached a short log from today's drive.

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[slows10]

Are you actually doing the calc vet method? The afrs are all over the place. Not sure what you are asking. Yes the calc vet method will correct the ve table and maf tables. Have you done it yet?

[slows10]

Your firsdt logs in your first post look much better than after this new tune you are trying. Also your timing is all over the place at idle. And it seems like it is low at idle.Did you do the rafig ? Why not fix the header leak also?

[pormgb]

Are you actually doing the calc vet method? The afrs are all over the place. Not sure what you are asking. Yes the calc vet method will correct the ve table and maf tables. Have you done it yet?

Ill be doing my first Calc VET tomorrow, this will be the first with the new tune.

[pormgb]

Your firsdt logs in your first post look much better than after this new tune you are trying. Also your timing is all over the place at idle. And it seems like it is low at idle.Did you do the rafig ? Why not fix the header leak also?

I've done a RAFIG that fixed most of my idle issues, at this point I'm trying to get decent AFRs.

[joecar]

Your maps in post #13 show that you are way too rich almost everywhere (as reported by your wideband).

[pormgb]

Your maps in post #13 show that you are way too rich almost everywhere (as reported by your wideband).

Ill run a Calc VET tomorrow that should fix my AFRs.

[pormgb]

Got the car running well, I went back to my closed loop tune because I didn't have enough time to get a good Calc VET log for open loop mode. I've copied stock B3618, 3605, while driving the car hard I can see low 13s, i did see a little knock on bank1 so I think I need to be bit richer. Do these logs look OK or do I still need go richer? I have also attached today's log file, please take a look to if anything stands out.

[pormgb]

Your maps in post #13 show that you are way too rich almost everywhere (as reported by your wideband).

Joe,

Posted my results (Post #20), how do these AFRs look?

[joecar]

Got the car running well, I went back to my closed loop tune because I didn't have enough time to get a good Calc VET log for open loop mode. I've copied stock B3618, 3605, while driving the car hard I can see low 13s, i did see a little knock on bank1 so I think I need to be bit richer. Do these logs look OK or do I still need go richer? I have also attached today's log file, please take a look to if anything stands out.Calc.VET is done with CL enabled.

[joecar]

Joe,

Posted my results (Post #20), how do these AFRs look?They look good, but the 95kPa column is lean.

[joecar]

Post some recent log files.

[pormgb]

Joe,

Posted my results (Post #20), how do these AFRs look?

I hope to get a few runs tomorrow, ill post those log files.

[pormgb]

Post some recent log files.

Here are two log files, the car ran fairly well but hesitates a little when I accelerate hard, I'm also getting some popping when coming off the gas.