SRT-4 table questions

[adarby84]

I have the newest vcm suite as well as the newest beta version. Trying to set WG duty cycle to turn the boost up but I do not see it anywhere under the torque management heading. I have sc/tc boost control with "turbo desired tq" and "max fuel pulsewidth", Under the Turbocharger subheading I have "Boost torque limit" by baro, by ect, by egt, by rpm, by time in boost, by vehicle speed, by gear, by knock, by fuel pw. Where in the heck do I go to increase duty cycle? I am running super fat at wot and want to throw some more air in the mix. Currently boosting to 15-16psi

Second question... Could someone post a pic of their VE table? I am currently running a stock stage 2 pcm and the ve table is full of sharp peaks and valleys, new to tuning but I thought it was supposed to be kind of smooth?

I have attached the stock tune file, my idea on the modified tune file (see if I am headed in the right direction with VE), and a quick data log.

Any help is so greatly appreciated!!!

[adarby84]

any body out here that can point me in the right direction?

[fixit]

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your fuel trims are way out, what injectors, base fuel pressure, return line, pump???

if your running a stock cam and stock head ve's should be the same (or very close) as factory.. peaks and valleys in VE map is an away to try and tune around it

[adarby84]

Yeah that was a stock stage 2 tune on fuel trims. Should be stage 2 injectors, I am not 100% sure on base fuel pressure I have to install a new guage, no return line, and supposedly has a 255 pump. Hans S20G kit agp wga with 15 pound spring 1.5 turns tensioned on the rod, Greddy Profec boost controller. Here is a new data log and tune revision. If you could help point me in the right direction. I am uploading two tune revisions, the profec low boost 3 is the current one I am working on. I changed my base stoich to .0730 to try and work around things. It seems to be doing better around part throttle cruise, but when I stomp it it keeps dropping to 10:1

I should say i am trying to upload the files, struggling here. May have to email if you dont mind shooting me a pm

[adarby84]

Here is the data log from last revision, it is not letting me upload the tune for some reason.

[B00STJUNKY]

Yeah that was a stock stage 2 tune on fuel trims. Should be stage 2 injectors, I am not 100% sure on base fuel pressure I have to install a new guage, no return line, and supposedly has a 255 pump. Hans S20G kit agp wga with 15 pound spring 1.5 turns tensioned on the rod, Greddy Profec boost controller. Here is a new data log and tune revision. If you could help point me in the right direction. I am uploading two tune revisions, the profec low boost 3 is the current one I am working on. I changed my base stoich to .0730 to try and work around things. It seems to be doing better around part throttle cruise, but when I stomp it it keeps dropping to 10:1

I should say i am trying to upload the files, struggling here. May have to email if you dont mind shooting me a pm

What are you trying to accomplish by setting your stoich to .0730?

I haven't looked at your logs, and won't be able to for a bit. But, ultimately, you should stop trying to tune it until you are sure you have figured out what injectors are in it, and have good data to start with.

Without at least having a close bead on injector dead times, you're just going to end up chasing your tail on consistency.

Also, turning up the boost doesn't automatically mean you're going to run leaner, that's not how things work with Speed Density fueling control (this is in response to your first post where it appears you said you're running rich, and you wanted to throw more air at it to compensate for that rich condition).

[adarby84]

I adjusted stoich to help make my PE table easier. It made sense to me to adjust that and have the majority of my table at 0 and run around 13.6-13.7 and then ramp it to 11.1-11.3 in the high load area. My last log I took this morning with my latest revision actually looked much better I think. I will admit I am obviously very green to this but have been reading and watching videos trying to learn. I want the knowledge and understanding so that as this car grows I can make the adjustments without having to rely on someone else. I try and take a log on my drive into work if I make any changes at the house or on the way home when I make changes at work. at least a 50 minute log for VE tables. I do not have my afr gauge hooked into my pro set yet, but watching the gauge it was much more stable than it has been. Still going super fat at full load and high rpm.

I pulled some percentage out of my VE table today and will log on the way home. I will try and post both tune and log file tonight or tm

[B00STJUNKY]

I adjusted stoich to help make my PE table easier. It made sense to me to adjust that and have the majority of my table at 0 and run around 13.6-13.7 and then ramp it to 11.1-11.3 in the high load area. My last log I took this morning with my latest revision actually looked much better I think. I will admit I am obviously very green to this but have been reading and watching videos trying to learn. I want the knowledge and understanding so that as this car grows I can make the adjustments without having to rely on someone else. I try and take a log on my drive into work if I make any changes at the house or on the way home when I make changes at work. at least a 50 minute log for VE tables. I do not have my afr gauge hooked into my pro set yet, but watching the gauge it was much more stable than it has been. Still going super fat at full load and high rpm.

I pulled some percentage out of my VE table today and will log on the way home. I will try and post both tune and log file tonight or tm

If you're running in closed loop, adjusting the stoich value will only have the net effect of skewing the fuel trims in the opposite direction of what you do to said value.

For example, let's say hypothetically you were running 100% gasoline (no ethanol mixed in), the stoichiometric ratio of gasoline is 14.7:1 AFR, or .0680 FAR (Fuel to Air, as the NGC PCMs define it). Setting your stoich to .0730 (which is the same as saying that the fuel you're running requires .073 parts of fuel to 1 part of air to be at stoichiometric ratio) would have the effect of the PCM delivering .073 parts of fuel for each part of air.

Obviously you would now be running richer than stoich by 7.4% (.073/.068 = 1.074). But, when the o2 sensors are enabled and driving fuel corrections, the result of setting the stoich value to .073 would mean the o2 sensors would read rich, and the closed loop controls would trim fuel out by pulling about 7.4% fuel to get it back to stoich.

Changing the stoich value in the calibration doesn't change what the o2 sensors and closed loop fuel correction system targets. So you're just skewing things even further from being properly calibrated by doing such a thing.

The only time it makes sense to change the stoich value in the calibration is when you change fuel types, and the new fuel type has a different stoichiometric ratio than pump gasoline.

Once again, you need to start out by determining what injectors you have and get proper data in the calibration for those injectors at the specific pressure you're running them at before you spend ANY time playing with your VE tables.