WOT spark timing issues...

[LETZRIDE]

ok, Im going crazy here now. Ive tripple checked all my tables, and although I cant get tiny tuner to work properly yet, Ive even looked into the timing tables they give us and I cant think of anything that will fix this.

My timing table is all over the map, non of it is what I am commanding in either high or low tables...all other spark tables I can see (the big 3, ETC, IAT, and base) are all zero'd out

for my WOT I am commanding 25* as my lowest in the low octane, but in reality Im seeing 24*, then when I step up to commanding 25* at 6000rpm I'm seeing 26* timing....so half my table is commanding under what I want, and half my table numbers are commanding more than what I want??

can someone give me a hand?

[bilemke]

Please post a scan with TP%, spark, rpm, maf (mass, not hz) and calculated cylinder mass at a minimum. IAT, ECT, AFR would be helpful too. Plus, of course, your current tune.

If you have a file you are trying to open in TinyTuner that isnt working, post that up as well. What is the issue with TinyTuner that you are encountering?

[LETZRIDE]

sweet, I can compile all my problems into one lol.

Posting my scan and configuration now...not sure if it matters though, I still have the BETA platform until I can redownload the other version and try using TT all over. (just not sure if you will be able to view the scans thats all)

Remember I am not MAF based, I am tuned through VE, although I do get MAF numbers, they are wayyyy wrong, try running the car based on those numbers once and it stalled out because of too much fuel.

not sure what you mean by calculated cylinder airmass?

Here is my current tune, scan, config

about the car

Car: 1996 Camaro 3.8L (97 pcm)

Engine:

cam 230/240 duration .512/.512 lift 113LSA
Heads fully ported/polished with manley valves (1.9"/1.57")
Full bolt ons (exhaust/headers/intake)
Electric Water Pump

Drivetrain

Ford 8.8 rear end with 4.10 gears
4l60E tranny
3200 stall converter

Tune

VE BASED! not Maf

Hope the above gives anyone looking at these scans a good idea of how the car is setup, and gives them enough background info, I tried to keep any mods listed relevant to anything regarding tuning. Let me know if anything more is needed...my sig is not up to date.

Attachment 29440

Attachment 29441

Attachment 29442

[LETZRIDE]

the file that isnt working in TT for me is this one:

Attachment 29443

[bilemke]

Oh yeah, you with the VE only tune on a platform designed for MAF. Thought I recognized the name.

Sorry man, can't help you unless you can provide a means of calculating cylinder mass off of "VE" in and all the other variables tied in to the way the PCM determines cylinder mass without the MAF table indicating airflow.

Quite simply, the main table driving timing advance is based on RPM and cylinder mass.. RPM is a given with a direct PID for it. But unless you can show cylinder mass as the pcm sees it, you can't say what the PCM should be commanding as you can't identify the cell in the table to look at or modify. Believe me, I have been there. The first tuner I had could scan the frequency signal of the MAF sensor but could not scan the MAF flow PID. Made tuning timing a guessing game at best.

Double checked you bin, I have had that OSID mapped already in TinyTuner. Being a 97 osid, I have pushed that mapping of that file quite far (I work on my 97 a lot).. Can tell you, there is not a spark vs manifold pressure modifier in there. You are stuck with cylinder mass and thus will need to know air mass flow use the tables.

[LETZRIDE]

so I don't suppose you know how to calculate cylinder mass?

Ive left the MAF plugged in so that it can continue to read the air so that I can still recieve spark data on those first 2 tables in hpt

[bilemke]

so I don't suppose you know how to calculate cylinder mass?

Ive left the MAF plugged in so that it can continue to read the air so that I can still recieve spark data on those first 2 tables in hpt

I see we are getting somewhere now..

1. Nope, at least not with 100% certainty that it is the way the PCM is calculating it. Mostly cause it could be referencing values in a number of tables most of us cant even see with out tuners yet.

2. If you leave the MAF plugged in, how do you know the PCM is not using the maf for not just spark calculations but fueling as well? And then, when you unplug it again it switches to calculated values based on VE that come out completely different then the MAF based calculations and as a result commands different timing?

[LETZRIDE]

I see we are getting somewhere now..

1. Nope, at least not with 100% certainty that it is the way the PCM is calculating it. Mostly cause it could be referencing values in a number of tables most of us cant even see with out tuners yet.

2. If you leave the MAF plugged in, how do you know the PCM is not using the maf for not just spark calculations but fueling as well? And then, when you unplug it again it switches to calculated values based on VE that come out completely different then the MAF based calculations and as a result commands different timing?

when I used to scan before I never had an issue. (previously just to be sure I would actually unplug the MAF sensor all together)This is while I was doing the initial VE tuning, and doing the AFR...then when I went to move on to spark I realized I needed the MAF to meter that air for those spark tables. So I tuned that with my old cam and unplugged the MAF again after I was happy and I could just see the spark on the graph only without the MAF in place (so I could see when I got KR, and what kinda timing I had at that point and all, but I couldnt see under which cell. So if I had 28* timing in all my WOT cells, I had to globally drop it 1-2* rather than just being able to drop it at the .92/6200rpm cell. If you get what I mean.)

But when I looked at my octane tables she sparked what I had commanded.

Now fast forward I have a new cam in there, so I need to revisit my tuning, so AFR is ok other than some fine tweaking needed, and I am on to spark...but like I said, Ive never had this issue Im having, and the only thing different is the cam/compression ratio lol.

[bilemke]

First guess, your cam changed VE enough to push it further away from values you have in the VE table. Basically, calculated cylinder mass is now less accurate.

[MMGT1]

So this means if he was to tune VE table via WB he could bing those #'s back in line, making the cly mass table effective again?

[bilemke]

Yes, assuming some other part of the grand equation is or has been not skewing the math.