proper way to populate VE?

[Tbi-MAX]

well so far my VE seems to be strong. no backpops out the intake or nothing, but maybe a tad rich in areas. the VE i came up with at 1st was like a stair step... they raised every 3 rows of map. im currently runing a more curved VE, that seems to run decent, but accels faster.. i guess im still confused how i properly make a VE from scratch.

i notice the engine would jump to certain map cells, (the correct one) for the amount of fuel it currently needs..

is it good to force the engine to read low map value cells? say 30-50map? (by making those value alot lower than the higher map cells)?

i want power when i stomp so thats why 70-100map is very sharp peak. but the transitions i want to be smoothe..

whats the proper way? or principle behind it?

specs in sig... do note with BBC injectors the VE needs a more steady VE.. thus 2 or 3 map cells in my tune are the same #s..

also who can link me to bin files, where i can compare both BBC and SBC VEs and other small stuff i want to compare, like AE etc.

[Red94Chev]

First off, I think there is more than one way of doing this. IMO, VE tuning without a wideband is mainly for tuning driving conditions other than WOT or PE. PE is enabled when the minimum TPS% thresholds for a given RPM are surpassed. The tables may be called "TPS threshold vs RPM for WOT" and "TPS threshold vs RPM for WOT (fast)", but this is the wrong title for them. WOT means wide open throttle, but as you can see from the tables, the WOT enrichment table is used even when TPS% is less than 100%. Some areas of the table have WOT enabled (i.e. lower commanded AFR from WOT table) below 40% TPS% even in the stock .bin. You need to temporarily raise these RPM TPS% values so you do not go into this sub-routine (i.e. 75%TPS) as this will skew the BLM data. You can leave the values a little higher as a fuel economy measure as well, so you're not enriching the A:F mixture with daily driving (especially at stoplight jackrabbit starts).

As you probably figured out, you can't get BLM data at WOT. It is fixed. You need to tune indirectly using the O2 sensor V to target 0.875V. This is where the wideband comes in handy to accurately measure AFR. Wideband is also needed to tune AE and DE. Near impossible without it. Also, you can change the BLM cell boundaries (Tables) to log higher RPM info and target the curved areas of the VE curve. To extend the RPM range of BLM enabled cells, you need to increase the "Maximum RPM to enable BLM" constant.

Lastly, you should remove areas of the chip that add/subtract fuel (i.e. AE MAP, EGR, CCP, Cat overheat protection, DE, etc.). HaulnA$$ has said many times before that VE tables are not fuel tables. There are other contributing factors that are adding/subtracting fuel and therefore influencing BLM values in your datalog. In order to populate the VE cells as much as possible, you need to cruise in 1st, 2nd, D, and O/D. Driving in 1st, for example, and then letting off the gas will give your low MAP values. Add the various fuel modifier elements back in and tune other tables beside the VE table now.

One last note, make sure you have no vacuum leaks or exhaust leaks before the O2 sensor. The PCM will think the engine is leaner than it really is and will add fuel. This will not show up in the datalog. Vacuum lines are so cheap. Replace them all for added insurance.

[Tbi-MAX]

what if im runing in OL? should i be in CL? here is the thing, i cant WOT for some reason, im still hitting walls.. like hickup. ive been from 15psi - 30 psi, and ive been thru 61# - 90# injs.. still i think my VE isnt right...

im getting ready to start over, but with a BBC base tune instead of SBC... but i also need it to be for 60e tranny.

can you direct me to the file? so i set PE to 0 while tuning VE? and DE... (do i have to set that to 100) to disable decel eleanment?

again im in OL, so no NB02

[93V8S10]

Just reading over this again and I think this might help.
http://www.fullsizechevy.com/forums/...ing-files.html
Download ScanerPro from Mark, then download my ScanerPro zip and VE Table editor zip. Should make tunning VE in open loop much easer.

I could be wrong but looks like to me all you would need from the BBC tune would be the injector offsets and AE settings.