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I am just learning this tuning deal. But the ol girl runs pretty good but its way fat at wot.
NN is turned off, I assume wot uses PE with it turned off . I have pulled fuel out of PE on sever tunes , no change to speak of .
Any idea anyone . Again I am just starting to learn.
5.7 long tubes, no cats, 3inch headers back ,holley sniper intake
I'd recommend turning NN back on, return your tune back to stock but use the volume of the Holley intake under "dynamic airflow", and tune your injector pulse widths using your fuel trims in part throttle, and lambda error in WOT (good threads on here show how to do it). When you're more familiar with setting up histograms / log tables, adding filters and offsets etc. then maybe try turning NN off if you need to.Quote:
Originally Posted by Speed39
The PE tables are used in WOT whether the NN is on or off.
Looks like you're running rich just about everywhere; not just WOT. Might also try going back to stock PE tables.
Start logging your pressure ratio, aircharge, and exhaust cam position.
You'll want to also power your wideband from a constant 12V source, so you can eventually tune your startup fueling (FA cold enrich table).
Ok I will work on it . thanks.Quote:
Originally Posted by rockystock
You, almost, never want to do that. It is, pretty much, a death sentence for the WB sensor.Quote:
You'll want to also power your wideband from a constant 12V source, so you can eventually tune your startup fueling (FA cold enrich table).
When the WB controller is on, the WB sensor's CERAMIC element heats up to about 680C/1250F ( glowing orange hot ). When hit with a rush of, relatively, cold air, the element cracks; just like trowing cold water on a hot windshield in Arizona. The cracks grow and spread, over time. 1st they ruin the calibration, with air leaks, etc. Then, the sensors start to get flaky ( randomly showing full lean or rich, etc. ). Then, eventually, the cracks hit something vital, and, the sensor fails, completely.
When the factory tests start-up AFR, they know they will end up with a bucket of ruined sensors. And, they check the calibrations of each sensor, before and after each test; to make sure the sensor has not drifted.
That's why you should NEVER let the sensor "warm up" before starting the engine. "warm" = 680C/1250F !
If you put the ignition key in RUN or ACC for a while, with the engine stopped, turn it off for 30 seconds, before starting the engine, to let the sensor cool down a bit. This one thing would save 90%+ of wideband sensors from an early grave.
Good info - thanks. My wideband has been a trooper so far (around 500 cold starts), but it's probably on borrowed time now. I can say that the stock FA Cold Enrich table was nowhere near adequate, especially below 40F. So I think it may be necessary to check the startup fueling especially after dialing in the rest of the tune.Quote:
Originally Posted by dr.mike
ok got it looking better but question . In scanner, how do I open the histogram window? Yea I know I should know this .
thanks .
Yes i do not let my wide band heat up before starting engine.
Maybe it has. Maybe it hasn't :) Hard to say, without verifying the calibration.Quote:
My wideband has been a trooper so far (around 500 cold starts),
It's fine, and worst case it's $40-60 to replace the sensor. Well worth the price for a better tune IMHO.
I looked up the thermal shock issues and found that the LSU 4.9 and ADV have greater resistance to thermal shock than others.
The ADV yes. But, the LSU4.9, just the opposite. Of all of the WB sensors, it is the MOST sensitive to thermal shock failures.
OK, thanks for your insight. I will use mine to get better FA cold enrich settings, and then buy new sensor(s) if needed. Hey while you're here, maybe you could weigh in a possible problem I had a few months back:Quote:
Originally Posted by dr.mike
https://forum.hptuners.com/showthrea...114#post617114
...and sorry to the OP, didn't mean to hijack your thread...
Its all good .Quote:
Originally Posted by rockystock
Here are a couple of tables to get you started. In VCM Scanner, you need to right-click anywhere in the "Graph" area, and select "Graphs Layout." Then, select the yellow folder "Open Layout File" and select the two tables (attached here). You'll have to click "Open Layout File" for each table.Quote:
Originally Posted by Speed39
You can see in the Graph Display Layout Editor that the tables will be listed on the left. Click on the tables and the settings for the tables will show on the right.
- The "PT_LTFT+STFT" table is named "ANN P/T RAW" (if that's too confusing, just change the names to match). It is a 2-dimensional table with row axis labels matching your fuel injector pulse width table in your tune file. You will need to start logging Fuel Mass cyl. 1 to see this table populate in your logs. There's no magic to cylinder 1, so you could use another cylinder, or even create a math formula to average several cylinders etc. But simply using cylinder 1 works fine for me. The same goes for the fuel trim formula - you can make a custom formula, but this one works for me too.
- The "VE-PT-B1" table is named "VE-PT-B1." It is a 3-dimensional table with column and row axis lables matching your VE tables in your tune file. You will need to start logging Pressure Ratio to see this table populate in your logs. You won't need the log data from this table when you're tuning with ANN on, but I've found it's nice to see what's going on with fueling in the VE table for better insight, say, if you want to tweak your torque model parameters further down the road...
Also you can see the filtering function I applied to the VE-PT-B1 table. Since I only want to log fuel trims in part throttle (and at normal operating temperature), the functions filter out low temperatures and any time the commanded AFR is less than 14.7 (that removes any glitchy fuel trims while in WOT, CAT Overtemp protection, or any other situation that makes commanded AFR go below 14.7. You could also add a filter, say, "fuel mass cyl.1 > 0" that can filter out fuel trims while DFCO is active. You can also use custom maths for the fuel trims, that will allow you to add offsets etc. to further remove any fuel trims around the AFR spikes before and after a transient, etc. etc. VCM Scanner allows a lot of customization and for me, it's been a good compromise for street tuning where you don't have the luxury of starting a log, then running in a specific scenario like you would on a dyno.
So for the 2D injector pulse width table, the fuel trim data that populates will represent the percent error of fueling in each of the pulse width breakpoints. If your log is "clean" (i.e., you don't have bad data from transients skewing your log), you could copy the log data and do a "paste special - multiply by %" into your "Inj PW vs. Fuel Mass" table in VCM Editor. when your errors are reduced to a few percent, do a "multiply by %-Half" to avoid over- or under-shooting your fuel trims. So after doing this, you end up with some new pulse width values for the given fuel masses. You need to copy those new values (select all the values and copy), and then open the inverse table, "Fuel Mass vs. Inj PW", open the row axis, select all and paste. Now you have adjusted your fuel injectors to give you some better fueling.
This approach is a good first step toward tuning for your new aftermarket upgrades, but this approach has also been referred to as "hacking the injectors." I believe there are more sophisticated things you can do to further improve these tunes, using other airflow and/or torque model tables (that use airflow parameters), but I've found most of them affect the tune in more subtle ways. With my setup, I'm attempting to make these other changes with the goal of returning the fuel injector tables back to stock as much as possible. My thinking is that the stock injector tables (or the tables provided with aftermarket injectors) are "truth" whereas the upgrades you (and I) have made so far are airflow-specific, so the best adjustments ought to be airflow-related in the tune. So the strategy here is to get your fueling close to normal now, and then go about experimenting with small changes in the other tables, watch your fuel trims to see if they call for returning your fuel injector tables back toward stock values, update the fuel injector tables (or go the other way with your airflow table adjustments if the fuel trims go in the wrong direction), lather-rinse-repeat... BTW, if any actual pros come on here and offer guidance that differs from mine, definitely follow their guidance :burnout: Good luck!
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thanks my friendQuote:
Originally Posted by rockystock
here is a short log with the 2d tableQuote:
Originally Posted by rockystock
give me your thoughts.
Looks like your log could be skewed by the low ECT. Your fuel trims went to zero during your three brief WOT hits so that's good (sometimes, my PCM locks in a few percent of trim during WOT...). I'd recommend copying the filter function (from the VE table I sent) into your fuel injector table. Also, you'll want to use a filter on the ECT that's maybe 10* above your thermostat setpoint so you populate the table with only the fuel trims at normal operating temperature. Any large fuel trims during warmup can be adjusted using the ECT Factor table under Airflow (just create a table in your Scanner that matches that table in your tune, and log your fuel trims during warmup).Quote:
Originally Posted by Speed39
Thanks for the tips. I am starting to understand !!!!;)Quote:
Originally Posted by rockystock