MAF table dialed in!!! *Tune almost complete!

[uk_hsv]

I have been working on a Monaro and have produced a car with a very nice tune.....

The VE is spot on and it always produces commaded A/F when in PE but I keep coming up with a problem......

when on the dyno/or highway on a full power run the PCM starts pulling timing (not knock) from about 4800rpm up to 6200rpm by about 2-4deg

If I do the same run in SD there is no problem, but I want the car to run a maf......

the current answer is maybe the Maf is going out of range! so I used the above excel doc (nice bit of work) and re tuned the maf but the new curve is within 2-5% of the origional and I still have the PCM pulling timing......

the max numbers are.
MAF (g/sec) = 40.47 (306.59)
Dyn Air (g/sec) = 40.48 (306.67)
MAF (Hz) = 10058
RPM = 6201

one other thing I noticed was that if you did a normal dyno run i.e. 4th gear low rev's and go WOT until 6000rpm the PCM would pull timing at around 4800 up BUT
If I had even throttle at 4000 the then went WOT I would have no timing pulled.

Is this because the sharp move into WOT at a high RPM meant the PCM used the VE table as a lookup until the Maf could regain control and therefore not use the Maf table?

this car is producing 410hp from a stock car but if I could get over this problem it would pull 420+hp no problem......

Any advice would be cool.............................

[txhorns281]

There are many ways the PCM pulls timing, log all your "retard PIDs" see why and where it's coming from. I know at least for me, I changed to a 160 stat and I had a little bit of timing being pulled from my ECT spark correction tables.

[uk_hsv]

The timing only gets pulled when using the maf.... in SD there are no problems...

temps on both runs are the same................

I have removed all spark retard from tables such as ECT,IAT etc etc for the maf runs and it still pulls timing!!

[uk_hsv]

Just for comparison I have changed to a 85mm maf and retuned the maf table (and VE)and this also pulls timing at 10000Hz

By the way a Granatelli 85mm maf has the same Maf table as a standard 73mm delphi maf with a small increase in flow so not a good buy for my application......

[txhorns281]

Have you tried your stock MAF to see if it still does it? ???

[uk_hsv]

I did all the runs on the stock setup and when this problem would not go away I fitted the 85mm maf as I thought it might have sorted the problem......

I will try a ZO6 85mm maf next just to check as that is now fitted to the LS2 Monaro and that runs 400hp standard (Corvette 450hp)

[txhorns281]

Cool let us know how you go!

[MNR-0]

I would love to know more about your Monaro.

[Arron]

The timing only gets pulled when using the maf.... in SD there are no problems...

temps on both runs are the same................

I have removed all spark retard from tables such as ECT,IAT etc etc for the maf runs and it still pulls timing!!

Have you tried a logging pid's such as Knock learn factor , AFR advance , base advance , coolant advance IAT advance , Smoothing advance etc.

How much advance do you have dialled in where you are seeing the timing pulled ?

[uk_hsv]

we have just finished setting up the Z06 maf (a little more work req on the curve) and we can now pull 28deg advance from 4400 up to 5800rpm (100kpa)with no timing pulled. ;D

The new maf flows more air than a mafless set up!!!! and drivers better in IMO......

The dyno sheets will tell all tommorrow!!!!

[DanaliHD]

OK, I don't get it. I tried following the instructions but i didn't get very far. Here's what i got.

put the truck in SD. Ok, from what i've gathered that means set the maf fail freq to 0, p0101, 01, and 03 to SES off. ok

log maf hz and dynamic air. Ok, so i open up a table in the scanner and delete all, add just those 2 things?

export the file. help me out with that, not sure what that means. how do i do that and where am i sending it?

Seriously, i'm lost. i suck, i know. lol

[MNR-0]

If its not knock, then its either burst knock or IAT retard.

[God_Forgives_IDont]

we have just finished setting up the Z06 maf (a little more work req on the curve) and we can now pull 28deg advance from 4400 up to 5800rpm (100kpa)with no timing pulled. ;D

The new maf flows more air than a mafless set up!!!! and drivers better in IMO......

The dyno sheets will tell all tommorrow!!!!

What were your results?

[02sierraz71]

Ive been trying to calibrate the maf from my ve sd table (its within 3%) and have used redsupras sheet and another from audio using trim levels. The values I get seem dead on the curve looks great and matches up to about 9250 where data gets scarce ( I only use the values between 2500 to 9250). Now comes the problem using the new values I turn back on the maf and all my trim levels are -11 and I get a code lt banks 1 and 2 rich, yes I did reset the trim levels. The car doesnt feal rich it runs well but not as good as in SD.


What am I missing I would like to run a maf.

[SideStep]

What were your results?

TTT

[devildog9999]

Hey guys... V6 question here on a SC 3800

I have read every post in this thread, and I just have one question. In the V6 version of the software, there is no way to disable the MAF freq to 0, so do I just copy high octane over low octane and then unplug and tune the VE vs RPM vs MAP, then plug the maf back in and re-calibrate using the logged data?

Do I also need to zero out the entire MAF table prior?

[WS6snake-eater]

Everything you said was correct EXCEPT....do NOT 0 the MAF table...That could be bad.

[RunnWS7]

Why do you have to log MAF in SD?

[02sierraz71]

here is how I tuned my maf table I simply logged maf hz and then pulled up the logged data in the chart and scanned with the cursor where I saw a trim out of whack I noted the range of the maf hz and adjusted the maf table accordingly. This has worked well for me.

The one problem I do have is that when letting off the throttle from wot I get maf hz values that are the same as idle values and it causes a lean trim. I thought it was the ve table but it isnt and the 02 readings dont relate a lean condition. Im puzzled by this and am now thinking maybe its the throttle valve is just shutting too quickly.

any thoughts on the problem or the tuning method are welcome

[SMOKINV8]

Would it be possible to get this sticky updated? HPT 2.0 has been released, and I'm still doing MAF tuning the same as I did with 1.7, which I understand is a very dated tactic when compared to 2.0. It isn't a major issue since I don't tune new cars on a regular basis, but I still think it would be good information to know.

Simply put, how do you use/set up the histograms in 2.0 to tune your MAF table?