Couple WOT runs Logs attchd

I made a couple WOT runs a few minutes ago. I have uploaded the logs. I am just hoping someone can look at the log and see if there is anything out of whack. I am mainly concerned with a little knock that is there on one pull and not the other and also the CylAir (g/cyl), it goes over 1.0 and my spark table only goes to 1.0, is this normal on a N/A setup. Also, can you please take a look at the commanded AFR vs Actual? Mods to the car are LS2 with LS3 top end, milled heads, long tubes, true dual X pipe and EPS cam 226/230 on a 110 +4. Also does the MAF (lb/min) look normal for a setup similar to this? I have a few custom histograms, one is Lambda MAF error% and Lambda AFR error%.

Thank you in advance for any pointers!

Bump

Only one log is shown in your post. Your wideband was reporting rich (upper 10's to low 12's) during that 4th gear pull when you were getting the knock. Usually when one sees knock you add fuel or reduce advance, assuming there aren't any mechanical or sensor problems. If the wideband was accurate, you're already too rich for a N/A setup. MAF rate is a little jagged, I would expect it to be smoother. MAP at is a little low in the mid-90s, indicating a mild intake restriction.

What method did you use to calibrate your primary VE & MAF tables? Usually the WOT areas of the VE tables (95kPa and up) will mimic the torque curve reported on a dyno, but your VE tables... while very smooth, don't look realistic for that cam. My first concern is that the airflow is not correctly modeled in the VE & MAF tables. If the airflow is wrong, it will calculate g/cyl wrong.

Yeah I worded that a little wrong, I meant a couple WOT pulls, not logs, there are 2 pulls in the one log.

I ran OLSD and tuned the VE as best I could, same for MAF, OLMAF only. I didn't get too much data in the higher kpa areas because it is hard for me to keep it at those high rpm kpa areas for any amount of time on the street. I have not had the car on a dyno, so a lot of the higher kpa and rpm areas are just extrapolated or inferred from a few readings I was able to obtain. I do realize that the VE should follow the power of the engine, there should be high areas at peak torque and then a fall off after, I just can't seem to get the data I need on the street to get the table dialed in. Even at the drag strip I only get a few hits in the cells and they are few and far between, not really enough to build the whole area. Does that make sense? In a quick WOT run the data skips from rpm column and kpa row so fast there really is no steady state data. Any idea why on one run I had a pretty consistent knock condition in the 1 g/cyl are and none on the second run in that same area? I am also contemplating switching out the stock iridium plugs with TR6s, I have read that some people had success eliminating knock by switching to a little colder plugs, especially on a modded motor.

Are you still running the 98 PCM with the LS3 motor in your car? If so would you mind posting a log and maybe a current tune so I can see some of your data, are you running the stock LS3 manifold, heads and injectors?

I think I am going to go back to the Closed Loop tunes for MAF and VE and try to dial them in a little more, my trims were really good when in CL but once I renabled open loop they started to drift pretty heavily to the rich side.

Thanks again.

It's definitely a challenge to safely do this on the street. The safest solution which will get you very close to optimal is to calibrate it on a load bearing dyno but I feel the most accurate will be a real street tune. You're not going to be able to populate the VE table a quarter mile at a time, but the MAF is easily dialed in with accurate equipment. If you have a drag strip, set up the logging and intentionally lose... at the light short shift into 3rd as soon as possible and go WOT starting around 2000RPM. Park and apply the changes, drag, rinse, repeat :) People at the strip might wonder WTF you're doing, though :D

Regarding the lack of samples, try to minimize the PIDs you're logging to maximize the polling rate. I've never used Iridium, always used TR55's in the LS1 and currently using TR6's originally gapped at .035.

Yes I am using the '98 PCM with my motor. The bottom end is stock except rod bolts, bearings, K1 rods & SRP 4.07" pistons. Top end stock including injectors except LS3 heads are milled .020 (I think), PAC valve springs & Rick Crawford modified L76 intake manifold. Coils and accessories are all LS1 using conversion harnesses. Current calibration, old VE log & matching config attached.

Thank you very much for the information. I just did a compare between our tunes and our timing tables are pretty close to each other, and our PE EQ Ratios are almost exactly the same! Your MAF values are a lot higher than mine, what kind of MAF are you running? I am going to work on my VE table some more, yours looks a lot better than mine. I am getting some surging at low rpms and my AFRs are not swinging so I was thinking it was timing and looking at your timing table, your values where I get surge are quite a bit lower than mine, I might try taking some timing away to help with the surge. Thanks again for all the help!

I'm using a LS3 card MAF in a Texas Speed 100mm MAF housing. I don't know if it's absolutely needed, it was merely recommended by a former(?) vendor here named Frost.

Hey - FYI - by my calculations, you - JimMueller got the 100,000th post in the GM V8 Tuning - Engine, Gas (Gen 3) forum. Kinda like watching the odometer roll :) 1slowbusa, got 99,999. If I calculated right :) Congrats!

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Originally Posted by Jack Daniels 383

Hey - FYI - by my calculations, you - JimMueller got the 100,000th post in the GM V8 Tuning - Engine, Gas (Gen 3) forum. Kinda like watching the odometer roll :) 1slowbusa, got 99,999. If I calculated right :) Congrats!

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Everything is proceeding as I have forseen. :secret: