2005 c6 corvette - tuning myself

[Dave_In_VA]

I've got a moderately modded car with a 60 - 70% tune. Build details are in my signature.

Tune was started remotely by a renown LSx tuner/cam designer (who bailed halfway through) and then continued by another Tuner that got it drivable. The STFTs are all over the place, it idles much rougher than when stock, it bucks and surges some, etc.

I'm learning to tune myself. I've got a MPVI2 and a LM2 wideband reader. I can read and write tunes and scan engine logs.

I've started working on a speed density tune. Used Schpenxel's tutorials to configure my scanner.

Anybody got a tune file similar to mine that I can look at and compare?

Dave

[dhoagland]

I don't see a signature with any info...
If you want a response from the "Big Boys" (which I'm not) you need to post a Tune and a Log

[kevin87turbot]

I've got a moderately modded car with a 60 - 70% tune. Build details are in my signature.

Tune was started remotely by a renown LSx tuner/cam designer (who bailed halfway through) and then continued by another Tuner that got it drivable. The STFTs are all over the place, it idles much rougher than when stock, and in general its just a basic tune.

I'm learning to tune myself. I've got a MPVI2 and a LM2 wideband reader. I can read and write tunes and scan engine logs.

I've started working on a speed density tune.

Anybody got a tune file similar to mine that I can look at and compare?

Dave

There isn't a signature with build details. What mods have you made?

[Dave_In_VA]

Attached are tune and log file.

[Dave_In_VA]

All, in looking at my current as compared to original VE table, I noticed that my current VE table in many areas are significantly below the OEM VE Table. The table below shows the change percent from current to OEM. A negative value indicates less fuel than OEM.

VE Tables Change to Actual.jpg

Before doing a SD tune, I'm thinking that I should go back to the OEM VE table plus adding some bumps in bottom right corner of table.

This evening I will try the above and see how it runs.

Thoughts anybody?

[dhoagland]

Can you post up your stock Tune?

The tune you posted doesn't seem to be in SD Mode
Also your LTFT don't seem to be logging

Really your errors don't seem to be horrible. Many of the ones that are way different only have 10 samples.

I think I would try to continue with this one

Also on Your Spark and KR log.
You need Cylinder Air Mass, Not MAP. Have your log mirror the spark table in your Tune

Do you have the Cam Card that includes Specs @.006?
Your End of Injection Boundary seems to be stock. And If you are injecting too early you can be blowing fuel right out of the open exhaust valve which can definitely skew your AFR readings....
I personally haven't tuned this yet, but I've run some different Cams through a calculator and see exactly what the point of adjusting this is

[Dave_In_VA]

Can you post up your stock Tune?

Please see attached.

The tune you posted doesn't seem to be in SD Mode
Also your LTFT don't seem to be logging

No, its not in SD mode yet. I started on that, but its still in progress. The Temp range is set to not allow LTFTs currently.

Really your errors don't seem to be horrible. Many of the ones that are way different only have 10 samples. I think I would try to continue with this one

This log session was very short. Will try a longer log session soon. I can keep working with this tune file.

Also on Your Spark and KR log.
You need Cylinder Air Mass, Not MAP. Have your log mirror the spark table in your Tune

Do you have the Cam Card that includes Specs @.006?

Thanks, I will correct the Spark & KR log.
Sorry, but I don't understand the statement/wuestion "Have your log mirror the spark table in your Tune"
Please see attached cam card. No 006 specs.

Your End of Injection Boundary seems to be stock. And If you are injecting too early you can be blowing fuel right out of the open exhaust valve which can definitely skew your AFR readings....
I personally haven't tuned this yet, but I've run some different Cams through a calculator and see exactly what the point of adjusting this is

Thank you for looking

[dhoagland]

"Have your log mirror the spark table in your Tune"

Sorry, bad explination
For your Spark & KR (actually all things you are logging in the scanner and wanting to modify tables in the tune)
Make sure all your column & row labels in your graphs match the tables in your tune, and you are scanning the correct parameters

So for your Spark and KR your graphs should match this (High Octane Table from your tune)

[dhoagland]

Okay
Do you have stock injectors (like what is in the original tune)?
Because the injector data has been changed

Are you sure the "original tune" is really unmodified? I'm going to try to find one in the repository to compare

Bottom line is we need to know what injectors are in this and get the matching data.
If the injector data is wrong Sooo many other things will never be right
(my opinion is you must have upgraded injectors at some point and the correct data is in there)

And If I were you I would start MAF Only Tune, get that dialed in, then go SD (Tune VE), then back to blended mode and address idle

[Dave_In_VA]

The injectors were upgrade to OEM LS3/7 43# during the build. The replaced injectors were OEM LS2 34# units.

I'm 99.99% certain the original tune was the one GM installed when the car was built. I got the car with 9k miles and original tires from factory (date code correct). Previous owners were all in the 70s or 80s.

Thank you for the previous explanation. I'll update my scan configuration.

[dhoagland]

10-4 on the injectors, that makes sense now.
Your Original tune does match one I saw in the repository

As I said, MAF tuning is easier to get a good baseline (unless you are heavily modified)

And for the End of Injection Boundary your Cam seems to have a pretty early exhaust valve closing with minimal overlap so I don't see a huge concern


Keep us updated on your progress, I don't think you are too far off.

[Dave_In_VA]

Is this video on MAF tuning a good one to mimic?

Its from Goat Rope Garage: https://www.youtube.com/watch?v=7IoWmLEmlvE

Thoughts anybody?

[dhoagland]

Is this video on MAF tuning a good one to mimic?

Its from Goat Rope Garage: https://www.youtube.com/watch?v=7IoWmLEmlvE

Thoughts anybody?

From what I remember its a pretty good video

Fail MAF with these settings pictured

[eXo3901]

Is this video on MAF tuning a good one to mimic?

Its from Goat Rope Garage: https://www.youtube.com/watch?v=7IoWmLEmlvE

Thoughts anybody?

The video is a good starting place. The main idea is slow smooth throttle transitions. After that you'll need to read up on how to filter your logged data. For starters, add Injector Tip Temperature and Fuel Trim Cell to your channels. ASSuming you will tune in closed loop and settle the drive-ability before you do WOT tuning, a simple filter could be: EQRatio=1.000 and (CoolantTemp>190 and CoolantTemp<210) and MAP>25 and (InjTipTemp>100 and InjTipTemp<135) and FuelTrimCell<16
Combine that will smooth throttle transitions and it will filter warmup/to warm, larger transients, most decel, Power Enrichment, and times when injector tip temp is to high/low. The idea is to capture data from when the engine is in its optimal running conditions or close to them.

FUEL:
Are you running e85? Your stoich table is setup that way, but flex is turned off? Alcohol PID reads 0% the whole log. If not, set that entire table to 14.69.
Set your injector tip temperature table back to stock. You can tune this table later, but I do not think zero'ing it out is the correct approach.
Your injection timing is modified. Not sure what the methodology was for the adjustments. Were they derived from a dyno session? If not, you might consider putting them back to stock. The idle area is close to stock anyways. (Boundary-ECT-RPM) Stock: 520-110-0=410 Yours: 520-105-14=401. To start, might be better off to just set the ECT table to 101 above 154F and RPM to stock then deal with injection timing later (and if you want, on a dyno.)

AIRFLOW-GENERAL:
Are you sure your IAT Sensor data is correct? Your Ambient Temp PID shows 100+. If the log was taken in the location you have in your profile and the date in the log is correct, the high that day was 78-80ish. Could be bad heat-soak, I don't know.
VE Table probably needs alot of work. Get the MAF done first though.
Cylinder charge bias table was changed to a GTO table? Maybe set that back to stock.

AIRFLOW-DYNAMIC:
Disable at 2,000 rpm is fine once MAF/VE are dialed in. Lower it to 400disable/300re-enable for MAF tuning. The HZ in the log looks usable at idle so I don't know why you wouldn't use the MAF. (When comparing blended MAF/VE to a SD tune)
All the dynamic airflow coefficient tables are set to 0 except for BASE and CURRENT. I don't really know the reason for this. Someone smarter than me could probably confirm the approach or debunk it. I would set them back to stock and see how things run.

SPARK: (Just my observations. Listen to smarter people if they chime in.)
Was this done on a dyno?
IAT Table is basically always pulling timing. Not sure if this was intended or not. Maybe start it at 122f instead of 86f.
ECT Table is pulling timing above .80 airmass. Not sure if this was intended or not. Maybe set the 194f column to 0.
Adding back timing on the GAS/Alcohol tables. Is this a flex fuel car?
-Normally you set timing on the HO table and use the ECT/IAT Tables to supplement (pull timing) for less than ideal conditions. (Again, check your IAT calibration data)
-Adder tables are generally zero'ed out so that the timing you see in the scanner is the timing from the HO table.
Retard/Knock sensor settings - I have minimal thoughts here. Some settings are not stock, but neither is your motor. You'd need a dyno to really know what to do with this stuff and even then stock data, except for burst knock, might be just fine.


Also keep in mind that the first few minutes or so after you flash the car the data is useless. I like to see InjTip temp, and coolant temp within a certain window before I start caring what the scanner shows. This is were filtering the data helps out a bunch, especially for street tuning.

[SultanHassanMasTuning]

if your still in need of support my info below

[Dave_In_VA]

All the dynamic airflow coefficient tables are set to 0 except for BASE and CURRENT. I don't really know the reason for this. Someone smarter than me could probably confirm the approach or debunk it. I would set them back to stock and see how things run.

Thoughts anybody?

[Dave_In_VA]

FUEL:
Are you running e85? Your stoich table is setup that way, but flex is turned off? Alcohol PID reads 0% the whole log. If not, set that entire table to 14.69.

No, the car is not running e85. Locally we have 93 octane gas that has 10% ethanol. I did a little searching, should I use 14.13 which appears to be correct for 10% ethanol?

[Dave_In_VA]

eXo3901 - Thank you for the detailed respone. Some comments are below.

Dave

Set your injector tip temperature table back to stock. You can tune this table later, but I do not think zero'ing it out is the correct approach.

I will set tip temp back to stock.

Your injection timing is modified. Not sure what the methodology was for the adjustments. Were they derived from a dyno session?

No to a dyno session. The current tune was done via a remote driving session during the height of Covid last year and the shop where I got a baseline dyno reading is now only open part-time as owner got a second job to make ends meet.

If not, you might consider putting them back to stock. The idle area is close to stock anyways. (Boundary-ECT-RPM) Stock: 520-110-0=410 Yours: 520-105-14=401. To start, might be better off to just set the ECT table to 101 above 154F and RPM to stock then deal with injection timing later (and if you want, on a dyno.)

I agree, push this off to later. I do hope to get a dyno session this fall.

AIRFLOW-GENERAL:
Are you sure your IAT Sensor data is correct? Your Ambient Temp PID shows 100+. If the log was taken in the location you have in your profile and the date in the log is correct, the high that day was 78-80ish. Could be bad heat-soak, I don't know.
VE Table probably needs alot of work. Get the MAF done first though.
Cylinder charge bias table was changed to a GTO table? Maybe set that back to stock.

Yes, unfortunately ambient was 100+. I will do the MAF first and then switch to VE tuning.

AIRFLOW-DYNAMIC:
Disable at 2,000 rpm is fine once MAF/VE are dialed in. Lower it to 400disable/300re-enable for MAF tuning. The HZ in the log looks usable at idle so I don't know why you wouldn't use the MAF. (When comparing blended MAF/VE to a SD tune)

I will do a MAF tune this week.

SPARK: (Just my observations. Listen to smarter people if they chime in.)
Was this done on a dyno?

No

IAT Table is basically always pulling timing. Not sure if this was intended or not. Maybe start it at 122f instead of 86f.
ECT Table is pulling timing above .80 airmass. Not sure if this was intended or not. Maybe set the 194f column to 0.
Adding back timing on the GAS/Alcohol tables.

My guess is that IAT was pulling timming due to the very hot day.

Is this a flex fuel car?

No

-Normally you set timing on the HO table and use the ECT/IAT Tables to supplement (pull timing) for less than ideal conditions. (Again, check your IAT calibration data)
-Adder tables are generally zero'ed out so that the timing you see in the scanner is the timing from the HO table.
Retard/Knock sensor settings - I have minimal thoughts here. Some settings are not stock, but neither is your motor. You'd need a dyno to really know what to do with this stuff and even then stock data, except for burst knock, might be just fine.


Also keep in mind that the first few minutes or so after you flash the car the data is useless. I like to see InjTip temp, and coolant temp within a certain window before I start caring what the scanner shows. This is were filtering the data helps out a bunch, especially for street tuning.

Acknowledge above.

[Dave_In_VA]

Ok, I'm got HPT configured. When idling and driving the AFR is in the 12.5 to 13 range, rich, but safe.

If I just rev up the motor it can very briefly hit 16+. Lean is mean and 16 is bad.

This doesn't seem to happen often, but it is happening.

Should I be concerned, or is this normal. If it were running 15+ often I wouldn't drive it.

The log from the first run is attached.




In case anybody is wondering, the following is what I changed as part of configure for MAF tuning.

Fuel > Cutoff, DFCO
1. Deceleration Fuel Cutoff
- Enable RPM 1300 => 8100
- Disable RPM 1200 => 8099

2. Clutch Fuel Cutoff
- Enable RPM 1000 => 8192

Fuel > Oxgeyn Sensors
3. O2 Readiness ECT -40 => 400

Airflow > Dynamic Airflow
4. High RPM Disable 2000 => 100
5. Low RPM Disable 1900 => 99

Spark > Advance
6. Base - High Octane Subtract 5d
7. Base - Low Octane Subtract 5d

Airflow > General
8. AvF Low Added 10%
9. AvF High Added 10%

[Arab Rider]

Hello, from where you got the injector data? I have 2006 corvette and I just installed LS3 engine with cam, LS3 injectors and intake. I want to characterize the injectors but in my file the pressure start in negative value.