1227747 $42 VE1 + VE2 Fuel Tables

[EagleMark]

That AMUR does not look bad at all? That 427 table is just so wrong... I've seen some huge issues with GM tunes, I think it was 1project2many who described the procedure. First engine dyno produces MBT, that's where it should have stopped! But then had to pass emmissions, then drivabilty, then emmissisions? Either way I don't think their software was as good as we have today so they just grabbed an area and fixed it! Hence the huge spikes and peaks. It passed so they were done, never really a fine tune. Just a theory... But looking at newer stuff is much more fine tuned. So were they trying harder or did software and technoligy make it easier? Remember the dates, computers and software of the era of ECMs we are talking about here?

Great information here gentlemen. This kind of stuff gets me thinking, which is why I joined this site :)

You know, I was thinking that it would be best to adjust all (or at least most) cells in the VE table, even though some you can't collect data on like Marks' example of 400 RPM and 100 MAP; or 3200RPM and 20MAP. I was thinking it would be best to adjust all cells whether you got data in those cells or not, that way you could avoid spikes and dips in the VE table, but now ya'll got me thinking that maybe this is just not necessary or ideal to do the VEs that way. I guess really the data is the final judge, as dave stated.

Now your thinking! Take your BLM readings and insert them into Daves Speadsheet, of course not all cells are filled in, look for patterns for low or high BLM or perfect and fill in entire spreadsheet to adjust not only cells with data but complete VE fuel table. Rinse and Repeat...

In the end data is king and the engine will run better with correct fueling. But in the final stages fueling will not be exactly smooth. Point of smooth tables was easier to tune to what engine wants! Data will be consistent, this way all the varibles will work properly. What happenes if you enter PE when BLM was changing from 128 to 168 to correct for wrong VE table? Well you don't get proper PE! Remember everything is an adjustment to main VE table, AE, PE, DFCO, choke... everything is an adjustment off main VE!

Also important point for anyone reading this, this is theory of 1227747 $42 VE. Other ECM/PCM may have areas that are not smooth nor are they supposed to be, for instance a PCM with 2 fuel tables for Idle and Off Idle, Off Idle should be smooth, Idle will not, there are areas that have to be close for transition, same for 2 spark tables. Other masks have other adders or subtracters that have to be considered.

[Ronny]

I believe you always want some value in Table 2. I used #5 for 400-3600 rpms adding balance to table #1 from #2. The idea is that there always has to be some VE in the adder table in order to have the VE lean out at high RPMs. If the ve adder table is zero, you cant reduce the VE after you have gone off the edge of the main table. 4000-4800 RPMs my adder would scale down like 45 @ 4000 35 @ 4400 and 25 @ 4800. Once youve done this you can leave the second VE table alone below 3600 rpm. Just work with the main VE table #1

[EagleMark]

Good tip Ronny!

Just last week I had a motor worthy of tuning at these RPM and that's exactly what I had to do or Wide Band AFR would not stay steady, kept getting richer.

[78monte]

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How does this look

[78monte]

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[78monte]

Sorry im having problems with the pic

[78monte]

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[dave w]

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That looks OK for a starting point, generally an engine at low RPM / light Load will need less fuel than an engine at high RPM / high Load. Engine modifications like aftermarket intake / exhaust systems might change the VE table.

dave w

[78monte]

This is after I smoothed then added the addr then smoothed again any suggestions im just trying to get a starting point being I havnt got the new ecm yet or the cables hardware I need

[78monte]

Anyone?

[dave w]

Good job on figuring out how to smooth in TunerPro RT. Not everyone gets that far with TunerPro RT. A starting point is just that, a place to start. Collecting a few data logs will be helpful with understanding the VE needs for your engine.

dave w

[hammertime371]

hey guys... Ive been messing around with my tune and found this post. I added the 2 tables together and see im over 100 in some cells. So does this mean I should lower the bpw and check again?

[dave w]

After adding the VE2 table to the VE1 table, ZERO the VE2 table parameters!

To be on the safe side, you could reduce the entire VE1 table by 2%, then increase the BPW parameter by adding 2 to the current value and see what happens in the data log.

dave w

[hammertime371]

ok thanks dave ill give it a try...

[hammertime371]

Im having good results with this...seems to have helped the cold start issue... however at what point do ya stop increasing PW and add more fuel pressure instead.. I went from pw 127 to 136 at this point and dropped all ve cells by 10 points