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Hello 3rd gen! I was hoping someone could help me out with a few questions I have in regards to tuning my supercharged V6 with the EBL-P4. I've read RBob's introduction to tuning and have been slowly trudging my way through the main EBL thread, but it's a lot to ingest...
I've got the low speed VE table pretty well adjusted, but it's a bit rough. I've tried smoothing it more, but the VE Learn sessions disagree with smoothing it out more than this. Should it be manually smoothed despite the fact that it will go against the VE Learns? There's a pretty deep valley around the 35kpa area that the VE Learn is very insistent upon.
Second question: I have two main issues with the tune that I'm trying to address and not getting very far with. The first is that the instant I press the throttle, the AFR goes very lean and stays this way for several seconds. The odd part is that it only does this in closed loop. In open loop, it behaves fine. This behavior can be seen in the attached datalog at the 00:07:28 mark. Is this due to Acceleration Enrichment needing more tuning? AE doesn't appear to be active when this is happening.
The other issue is that it runs leaner than it should at >50-60% throttle. PE kicks in and sets the cAFR to 12.6-12.8, but the wide-band only reads ~13.3. Is this because my 22# injectors can't keep up? Or an issue with the tune that I'm missing? This can be seen (slightly) around the 00:07:35 mark. The discrepancy between the cAFR and WB grows as you get closer to wide-open throttle.
Sorry if these answers should be obvious, but this is my first time tuning a vehicle...
I've got the low speed VE table pretty well adjusted, but it's a bit rough. I've tried smoothing it more, but the VE Learn sessions disagree with smoothing it out more than this. Should it be manually smoothed despite the fact that it will go against the VE Learns?
Yes, looking at your graph it needs to be manually smoothed.
Originally Posted by Shadow9x99
I have two main issues with the tune that I'm trying to address and not getting very far with. The first is that the instant I press the throttle, the AFR goes very lean and stays this way for several seconds. The odd part is that it only does this in closed loop. In open loop, it behaves fine.
This is because your idle air/fuel in Open Loop is 13.5. Once Closed Loop enables it targets 14.7 AFR. The difference between the two in relation with your AFR starting point off idle is the reasoin why you're hesitating momentarily in Closed Loop. Increase your AE in increments of 5% in both the TPS and MAP columns until you're satisified with Closed Loop off idle, then stop...
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Originally Posted by Shadow9x99
The other issue is that it runs leaner than it should at >50-60% throttle. PE kicks in and sets the cAFR to 12.6-12.8, but the wide-band only reads ~13.3. Is this because my 22# injectors can't keep up? Or an issue with the tune that I'm missing?
So long as your injectors are not maxed out, if your fueling is too Lean you need to increase the VE in that area. Don't rely solely on the VE Learns, they will get you close, but in the end you need to fine tune. Best of luck with your build...
After an afternoon of manual adjustments, the car seems to be running much better now. I've also discovered that having a very consistent IAT is key to getting the VE table correct.
One more question though: what is the target AFR for the VE table? Is it 14.7:1, or the value shown in the cAFR field in WUD?
One more question though: what is the target AFR for the VE table? Is it 14.7:1, or the value shown in the cAFR field in WUD?
The cAFR on the WUD screen is telling you what the commanded AFR should be at that exact moment in time, you will see it change when other parameters are being triggered, eg; cold start OL will show a very Rich target while working its way Leaner as the engine warms up, should be no Leaner than 13.5 AFR at part throttle, PE will be around 12.8 or so unless you adjust that commanded target, Closed Loop will always be stoich, so if your stoich value is set for 14.7 (gasoline) thats what will show as being commanded, not to mention Highway Mode which will go Leaner than 13.5 AFR for MPG purposes. The VE itself though should be stoich, the other areas base their commanded increases and decreases from that, this includes your Boost fueling tables, so be sure your VE is as close to stoich as possible for the fuel you're running...
09-28-2022, 09:56 AM
