Help understanding this VE table

[EvilTSi_97]

Hey all,

I have been using Eric's Excel spreadsheet a little bit and have made a few 2nd and 3rd gear pulls under pretty low boost for the fuel I'm running (E85). I can't wrap my head around why this VE table looks so darn scattered. It doesn't seem like the cells should jump so high from each cell to the next that much. Also, after corrections from this run, two VE cells are reporting 115. I imagine this isn't TOO far out there, but maybe it will raise some eyebrows to those with experience (hint hint Eric, Craig, etc). Would this indicate that my global fuel is off just a little bit?

I did notice that I am making some good progress despite the weird looking Christmas tree I call my VE table. After applying some of the calculations, it really wakes up around 4,000 and you better hang on If you notice the third gear pull, it starts to smooth out really well from mid pull to end. Just need to smooth out a few more tables and should be good to go.

Anyhow, a long story short...is it normal to have VE values in the 110-115 range? If not, is it a global fuel issue?

As a bonus...do any of you SD gurus know how I could take the data I have in my VE table for the boost level I have been tuning at (roughly 21psi) and help me extrapolate the table to get somewhere in the ballpark for higher boost levels? For example, at the 37.5 load value is where the 21psi of boost comes into play. I would like to be able to say "Okay, if this is what my VE table looks like at this load value, then at 40.4, 44.1, 47.8, etc should be *roughly* these values."

P.S. Getting closer and closer!

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Thanks!

Brandon

 

[compression]

Cant pretend to know why your VE table looks like that, but i did get bored and attempted to "smooth" it out. take it or leave it

 

[EvilTSi_97]

Cant pretend to know why your VE table looks like that, but i did get bored and attempted to "smooth" it out. take it or leave it

Now that VE table looks really nice! I wish I could get it to work with my setup, though. If you open my log above up in ECMLink, scroll to 5.636 seconds in the pull. Then, go to the SD table and track datalog. If you notice the VE value there is 86.5. Why it's 86.5 when the others above it are in the 100+ region is beyond me. I am starting to think the cams I have in here are really killing me. However, it shouldn't be load based, right? I would only think it would affect a certain RPM range. Right at that mark AFRatioEst and WB line up exactly.

I do appreciate you taking the time to do that for me! I just wish I could plug it in and go, but for some reason my car wants to have all the pretty colors for a VE table.

I suppose it's fair to assume that as long as the car is running fine, no knock, WB and AFRatioEst line up, then everything is probably fine even though the table is really funky and makes no sense?

Brandon

 

[knochgoon24]

That is weird. Something isn't right.

Mine isn't the greatest example, but should point you in the right track.

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No crazy cells in the middle. It's smooth.

I think my injector scaling and latencies are off. My VE numbers are larger than most. It also doesn't follow 1:1 between boost and load. I'm still debating if I want to go back and retune it to follow 1:1, or just adjust everything else around the current tune.

 

[EvilTSi_97]

That is weird. Something isn't right.

Mine isn't the greatest example, but should point you in the right track.

You must be logged in to view this image or video.

No crazy cells in the middle. It's smooth.

I think my injector scaling and latencies are off. My VE numbers are larger than most. It also doesn't follow 1:1 between boost and load. I'm still debating if I want to go back and retune it to follow 1:1, or just adjust everything else around the current tune.

Yeah, in a few ways yours does look similar to mine, but without the crazy jumps in cell values. I think the thing that bothers me most is that it runs great, but I don't want to be compensating for a crummy AFPR or having global fuel settings a hair off.

I did notice you have some pretty high VE values. I did some reading last night and found it is pretty normal to have high VE values for turbocharged motors, but I wonder "how high is too high".

 

[knochgoon24]

I'm not sure what's "normal" either.

It used to be that people would tune so that load and boost (kPa) ran 1:1. But now some different methods have appeared, including the one I tried this time, where you just plug in basic injector info, set the non IAT and baro compensated load to run 1:1 with boost, and then adjust the VE table to get the fueling right. Then adjust the timing as necessary.

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I can't say that I like this method at all. But it took me so long to get the tune to this point, and the car is running pretty good.