thunder550

iTrader: (70)

I've been running a 2 bar OLSD tune for awhile and have been having issues with low RPM/boost knocking. When I transition from vac to boost I think the bypass valve on the Radix is closing so quickly that the PCM can't keep up, so I run from stoich to lean (15 or 16:1) before it richens up to 11.5:1 as commanded. I was told that I can re-enable the MAF and it would remove much of the tip-in lean condition. My question is this: Should I tune in OLSD to get my VE tables down correctly, then just reattach and re-enable the MAF? Will I be able to run a closed loop 2 bar tune? I am running a max of about 9 psi, so I should be within the limits of the MAF sensor. I am using a 2-bar EFILive custom O/S.

wait4me

iTrader: (10)

You can trick the computer to use a totally different set of timing while commanding different Air fuel tables when using the custom os 3 from efilive.

Look for the table FUEL MIXTURE SPARK CORRECTION table B5908.

Basically, with this table, you can modify your timing for less or more timing durring those commanded air fuel ratios.

kbracing96

iTrader: (25)

Chris, its easy to do. (I'm running this way now) Just re-enable the MAF and then setup a BEN map for the MAF freq table. Then just autotune it like you would with the VE table. You will probable need to add a bunch to the MAF table, as I did to make it rich enough in the high freq numbers. Thats how I did it. BTW, with my 4.8, I'm close to maxing the MAF at 10psi and 6200 rpm.

Call me if you need some help

thunder550

iTrader: (70)

Cool, thanks for the tips guys. Anything I will be giving up by switching from OLSD to MAF?

thunder550

iTrader: (70)

Also, looking into which MAF to get. Suggestions?

So do I tune the VE tables first then plug in the MAF and tune it as well?

dc_justin

iTrader: (13)

If you adjust b0120 (Airflow Calculation threshold) to something very low, like 100 rpms, then it doesn't matter which you tune first, VE or MAF. With B0120 that low, fueling calculations (MAF+VE) are disabled and only measured airflow will be used (MAF).

kbracing96

iTrader: (25)

Why don't you just go to the dealer and buy a new one. That way in a couple months when you change your mind AGAIN, you can sell it to me for 1/2 price

dewmanshu

iTrader: (4)

Alright, efi guys hogging the scene...I have an HPT question...I am gonna be getting my emission notice soon enough. I am 2bar OLSD. I tried just for ***** and giggles to renable the maf and it is like it disables pe/be. You mash the gas and you just get leaner and leaner. Theoretically, can't I just fatten up my maf big time? Then get my readiness tests to pass so I can do emissions and go back to mafless.

kbracing96

iTrader: (25)

I don't see why not. You would just need to create a "histogram" I believe is what HPT calls them and tune the MAF table. FWIW I think I added at least 6% to the middle-upper parts of the MAF. Just keep it looking smooth with a nice arc

dewmanshu

iTrader: (4)

oh it's so bad though, I'd have add like 25% to it before I even bother with the error% log(the custom hist). It's only to get emissions, but I'd have to drive it like that a few days to get the readiness test to pass (or fail).

thunder550

iTrader: (70)

Well I went back to the MAF, throttle response seems much crisper. I'll have to get the tuning done and see how much better it does.