Dave F

If you just log the LTRM's without changing/removing the MAF, can you make any usefull adjustments? In other words, can you adjust the PE table/MAF, or do you really need to run MAFless to know which table is "off".

Just curious if they can be tuned while running together.

Dave

ringram

You wont know what table is out, the ve or the maf.
You will be changing blind. Disconnecting the maf allows you to correct the ve, then once you know ve is ok you reconnect the maf and will know that its the maf table thats now wrong and needs correcting.

soundengineer

iTrader: (16)

with the case of the MAF 's that have the IAT in them...you cant just disconnect it....
you have to just set MAF fail to 0 and set the DTC to MIL on First error.
or you need a seperate IAT sensor from the MAF

you must remove the MAF from the Equation and be in SD mode to check the VE table
and then after it is correct, you can then re-enable the MAF and check it....
you can do trims to check it if you want...but I suggest a wideband check as it will be more accurate.

Dave F

yes, I know about the IAT...

Thanks ringram, that's what I thought. I was just curious about that.

I'm going to start tuning my 2005 LS2 street car next week, and since LS2 tuning is pretty new, I'm just trying to make sure I understand the basics and my options.

joecar

That's why you must first calibrate or calculate these items in the following order:
1. IFR table (calculated)
2. VE table
3. MAF table

For VE table tuning, you don't want any influence from anything else, so you have to be MAF-less (SD), open loop, PE restricted/limited; and a WBO2 helps ALOT (shows real AFR).

Otherwise if you leave the MAF enabled during tuning, you can only assume that VE table is okay, and you can only adjust the MAF table.

soundengineer

iTrader: (16)

PE does ot have to be restricted or limited in any way....If you tune with a wideband you just tune the VE with PE enabled just as you would use it...no different...and use AFR error % to get the VE correct.
you dont have to tune in open loop..you just use Ltrims when in closed loop....you always need a wideband for any open loop stuff

Bombguy99z28

What he said.

joecar

Okay... I'm just trying to understand it better...
How do you account for PE influence when altering the VE table...?

soundengineer

iTrader: (16)

the standard way to do VE is to set the OLFA to 1.0
leave the PE set to how you want it to be while you dive it normally...
tune using AFR Error %
the car will command what it needs in PE..afr error still works the same...
basically 100*((AFR-Comanded)/Comanded) = AFR Error %
and you log Commanded AFR and Actual AFR

then you are guaranteed to get the right AFR during PE....
unfortunately the computer uses a multiplier for PE...its not always accurate...
if you tune you whole table to 14.7...and then enabe PE after the fact..you will notice that anywhere your PE kicks in..is not correct..I dont know why..I just know from a little experiment I tried myself to see for sure.

you have to tune it exactly as you are going to drive it.

when you are done you need to tune OLFA.as soon as my new sensor shows up I will be completeing a half written writeup on this matter