Need help with tuning cammed LS3... please! Will paypal you a TIP! $$

[n8dogg]

2008 Corvette LS3, Manual Transmission, LG Motorsports G6X3 Cam, Stock Heads, Long Tubes.

I am trying to perform a MAF only tune, and eliminate the VE Correction. Right now VVE tuning would require much more time than I have on this car. I seem to have dialed in the MAF fairly well, I am seeing 1.0 Lamda values when commanded. Here are my issues:

1.) No Start, unless you put the throttle down part way.

2.) Surging at low RPM and light throttle %.

3.) Feels under powered at low RPM.

If someone can help me out I would appreciate it. I'll even paypal you a gift for the help!

15531
15532

[wesam]

Do you have wide band ?
Could you log a WOT run with wide band ?
I will help you after sending WOT log

[n8dogg]

I posted a log with the use of a WB. Take a look at it, I can post more if you'd like. Also getting a P0606 MAP performance Code, any suggestions?

[wesam]

I checked the log you sent but it seems that there is no WB reading also you need to log ETCTP for DBW TB
Also you should log VSS and MAF freq

[n8dogg]

Weird, because it displays my WB data just fine for me. It's 10 slots from the bottom; External Wideband Lambda

[n8dogg]

Here are two more log files. If I could go out an log some more data for you, I would. But I wont be at the car until I get to work and am crunched on time to get it going for the guy.

15536
15537

I made some changes to spark and idle/crank settings. Here is the current tune; 15538

[wesam]

It seems your car is too rich at WOT
Lambda 0.745 !!!
It should be in the 0.86 range
I will modify you tune file and send it later today

[n8dogg]

Excellent, I wonder if it is a PE modifier of some sort, because my commanded is near .80.

[n8dogg]

Any luck? I'll be heading into work in a few minutes. I guess I'll play around with the tune and see what I come up with in the meantime.

[wesam]

What fuel are you using ?
why your stoic afr is set to 14.12 ?
Try this file but keep an eye on the KR and AFR

[n8dogg]

What fuel are you using ?
why your stoic afr is set to 14.12 ?
Try this file but keep an eye on the KR and AFR
Wonderful 10% ethanol/e10. will try it shortly thanks!

[n8dogg]

Loaded the tune, still has a no start with out putting the throttle down. I think it needs more air. What tables to adjust to give it more air during cranking? Here is a log during crank; 15542

[wesam]

There is some thing wrong with your last log file I could not view it correctly
could you upload it again please
also try this file and check if it will start without throttle

[n8dogg]

She started with no throttle, barely. Maybe a touch more air? I can modify the table if you point me in the right direction. I will log a road test right now. Wideband is being used on another car right now, will keep it in part throttle only.

[n8dogg]

OK, just got back. Improvement to throttle response and acceleration at lower RPM. BUT it still surges, I noticed it surges most at 25% to 30% throttle, with 40+ degrees of timing. Maybe scale timing back a bit in those areas? Or change fuel to 14.12 stoich for the E10? I think PE AFR is too lean, feels slower than when I had it commanded for 12.2. Also, still getting the MAP code P0106.

Here are two logs; 15544 15545

[Taz]

... still getting the MAP code P0106 ...

Change:

C0404 = -40 F
C0405 = 300 F

You may also want to change:

B8024 = 500 RPM
B8025 = 490 RPM

If you don't get this sorted out by early next week (I have no time to look at this until then) - PM me your email address - could send you a tune that should get you started.

Hopefully you gents get it sorted out ...

[n8dogg]

Thanks Taz, I'll give it a go. Which tables should I play with to get it to start easily with no throttle application?

[Taz]

I am certain you have probably looked at this thread, despite being very long, it is information laden - a mandatory read. You should be able to condense the 24 pages to about a third that amount.

http://forum.efilive.com/showthread.php?9740-E38-idle-tuning

The E38 and E67 are excellent at controlling airflow - once you get use to them. I find they are actually easier to tune the idle for larger camshafts than the LS1-B PCM.

Obviously, there are numerous interrelated parameters - some general places to take a look at are:

Start up: B0138 / B1829 / B1832

Idle: B1829 / B1843 / B1845

Plus many others ...

[n8dogg]

Yeah, I have referenced that thread a few times. My concern is the idle is great on this car, and don't want to risk hurting it.

[wesam]

Not just a single table
but mostly the cranking air
try this file and report back about surging

[n8dogg]

Tried the file, still surges just like before. I increased the Idle Minimum Air Value table in gears 2-6 between 1000 and 2000 rpms, seemed to help very slightly. Still has a slight surge, all gears with light gas pedal pressure. Under 30% throttle is most noticeable, negligible above 30%.

[n8dogg]

I brought the stft's down by decreasing the MAF calibration. Also adjust PE AFR to 12.4, feels better at WOT. Acceleration and PE feels great. Just that darn cruise now. She seems to start OK with out the gas, a little hesitant, but it starts.

[n8dogg]

15547

Current tune file

[EagleMark]

Also adjust PE AFR to 12.4, feels better at WOT. . E 10 fuel is about 11.9 AFR for WOT PE, your lean... can't you change this to EQ ratio?

[EagleMark]

Where'd your post go Joe?

There's a little catch here depending on what B3605 is set to? If set to 1.0 for operating temps like some .tun then PE B3618 is closer to 11.9 AFR to obtain .86 Lambda on WB with E10. But if B3605 is set to richer then 1.0 at higher MAP like some .tun then PE will be less. Set up the tune tool for EQ and loose the AFR...

My B3605 in stock form is 1.0 across the board at operating temps and I needed PE B3618 set to 1.15 to obtain .86 on WB.

In the end WB is right.

[joecar]

I looked at his tune file and his PE is set to 1.17x EQR, so what I said did not make sense...


+1 EQR in the tunetool


regardless of E00/E10/E15/E20/E85, for NA, PE should be close to 0.86 lambda (1.165 EQR) [ noting that 1/1.165 == 0.858 =~ 0.86 ]

( the stoich AFR for the fuel being currently used should be set in B3601 )



For LS1B I found that the PCM chooses the richest cell from the active fueling tables (I don't know if this is true or not for E38/E67)...

so in OL, if B3605 is richer than B3618, then the PCM uses B3605...

[ experiment: set B3605 and B3618 to cross each other at several points, and observe the commanded fuel pid ]

this means when a protection mode activates, its fueling table becomes a member of the currently active tables;


( note that in CL B3605 is not active, i.e. B3618 is the only active fueling table when PE enables )

[EagleMark]

Unless B4206 is set to enable... was my issue... thanks joe!

[joecar]

Unless B4206 is set to enable... was my issue... thanks joe!Hi EM,

"unless" to which part...?

[EagleMark]

In CL B3605 is not active, in OL B3605 is active, but if B4206 is Enabled your still getting STFT... It's a glitch when tuning the 0411 conversions as the Express Van tunes have it enabled. IIRC other LS tuns do not, or at least the ones I compared to when I found this as nothing was working correctly OL with WB.


For LS1B I found that the PCM chooses the richest cell from the active fueling tables...

so in OL, if B3605 is richer than B3618, then the PCM uses B3605..This is what the thanks was for! Good info! :master:

[joecar]

Yes, B4206 is OL STFT (implying that B3505 is active).

[n8dogg]

If you don't get this sorted out by early next week (I have no time to look at this until then) - PM me your email address - could send you a tune that should get you started.

Hopefully you gents get it sorted out ...

Hey Taz,

Any chance you can give me a hand on my tune file? I'll have the car back in a couple of days. It's running pretty good now, I feel like there is still a little surging at light throttle application, but customer says he doesn't notice it. After the most recent re-tune, his complaint is decrease in power at higher RPM's. I didn't change any spark or fuel tables up top, not sure how that would have changed. I have the tune running in MAF operation only. Here is the current tune file: 15580

[n8dogg]

Or anyone for that matter :X

[Taz]

n8dogg,

Sounds like you are close enough for the customer, and nearly close enough for yourself. Any base tune that I could send you would mean a partial rework of what you have already done. Not about being right or wrong, merely different avenues to arrive at a similar end.

Regarding the minor surging / bucking you described ..... log RPM, air per cylinder, spark advance, and knock retard (plus any other PIDs you wish) during these events. If your airflow (MAF or VVE) is close, then often the solution is as simple as adding a few degrees of spark advance in the low RPM / light load areas where this anomaly typically occurs.

The changes to spark advance in the appropriate cells will typically look like a "bell" curve ... perhaps 1 to 3 degrees on either end, with as much as 10 degrees in the middle (if beginning from stock spark tables on a cammed vehicle).

EDIT: forgot to explicitly state - change the High Spark table only during this exercise