1320ft

iTrader: (3)

Background info: 1998 Camaro SS A4 - HPtuners - ALL stock except for a flowmaster muffler (some tuning the easy stuff )

So I am set up to start logging my fuel trims to tune my VE. I have done all the stuff to put me in SD mode. I was doing some more reading to understand things better and now I have a question on which VE table do I modify, secondary or primary? Apparently my car will fall into the secondary VE when I go to SD mode. So doesn't that make tuning the primary VE useless? Once I adjust the primary VE via the logged histograms, then reflash the PCM, nothing is going to happen because the car will not be using the primary anyways? So how do I go about tuning these tables?

I will be re-enabling the MAF as well when I am done.

Thanks to anyone who can straighten out my confusion

foff667

iTrader: (2)

as stated in the help file

1. Start the HPT Editor & open SDStarter1.hpt
2. Start the HPT Scanner & open and open SDtune1.hpl
3. Open your pre-configured AFR error % histogram & set cell his required to 50, click average & load all data.
4. Next highlight & copy all cells
5. Switch to the SDStarter1.hpt file & open your main & secondary VE tables & paste special-multiply by % to the main & hand blend the surrounding unaffected cells. Then copy each line to the secondary.
6. Now Save your tune as: SDtune1.hpt & perform a calibration only reflash to the PCM
7. If necessary repeat the until the average cell values in your AFR error map(s) are close to 0 (aim for +/- 1%).
8. At this point if you have completely removed your MAF & have made the decision to never use it again you are done and can go about your way. If you are going to put your MAF back on keep reading.

1320ft

iTrader: (3)

Thanks for the info! That's for tuning with a Wideband, right? I don't have one of those yet. I am trying to tune with my fuel trims. Thats what confuses me, cause if I log the fuel trims then copy and paste those to the primary VE, when I go to make another log my fuel trims will be unaffected right? Since I am in SD mode and my car defaults to secondary VE.
None of the write-up's that I have read deal with tuning the secondary VE, just the primary. I understand the steps in the process but cannot see how to get there with two VE tables......

TAQuickness

iTrader: (28)

1320ft - You should look into getting a WB. You can tune with trims, but a WB makes life a lot easier and gives you a more accurate representation of what's going on in your engine.

brad8266

iTrader: (23)

He can tune his LTFT's easily without a wideband, it is not needed in closed loop. The stock O2 sensors are very reliable when you are operating at or close to stoich. I dont use my wideband at all when I tune LTFtT's. When you tune WOT though, you surely want a wideband.

Slowhawk

iTrader: (12)

I wouldn't tune SD without a wideband.Makes life alot easier. If your tuning closed loop a wideband isn't needed at all.Well, FI cars I'll use a wideband but not NA.

1320ft

iTrader: (3)

Thanks for the thoughts. I understand what I am suppose to do with the fuel trim tuning. My question is concerning the primary VE table that is NOT being used when I am in SD mode. It seems like a one shot deal: I log the fuel trims >copy and paste histogram into the primary VE >copy and paste all rows from the primary that are related to secondary (20,30,40 etc.) >reflash PCM. Then I am ready to log again but the primary table is going to be useless right? Because my car is going to be looking at the secondary table only, by default of the SD mode. So then how do I go about tuning the primary table AFTER the first log??

(I realize there are more details in the logging and tuning process, but I am just trying to get to the point )

I beginning not to like two VE tables very much........

brad8266

iTrader: (23)

yeah 2 VE tables sucks, I want a post 00 operationg system soon. You can just take the values from the secondary table and paste them in the primary table and then hand smooth the primary table to fill in the gaps.

foff667

iTrader: (2)

try this http://www.thetuningdoctor.com/Excel...0VE%20calc.xls it should definitly help just fill in your primary & it makes your secondary.

dynocar

Why would you use a WB on FI but not on NA?

1320ft

iTrader: (3)

Thanks for that excel spreedsheet, pretty sweet So I am going to have to tune by copying and pasting my fuel trims into the secondary VE. (Since the primary is being ignored in SD.) Then copy those values into the related primary VE. Then re-log go through the same process. Then hand smooth the graphs at the end of it all when my trims are good? Is this going to work out ok when I enable the MAF?

foff667

iTrader: (2)

1. copy-paste special-multiply or multiply by 1/2 to your primary VE table
2. take corrected primary VE table copy-paste into that excel file I posted
3. copy new secondary VE table that the excel file produces for you
4. paste new secondary VE table into the hptuners editor.
5. load new tune
6. rinse, repeat.

1320ft

iTrader: (3)

Ok, thanks. I'll give all this a shot and see where it gets me.......

Thanks for everyone's help, much appreciated!