Throttle VE

[oztracktuning]

How do we use the new Throttle VE tables in the E38 operating system. Has anyone had a go with this feature.

[ringram]

Im guessing tuning them is the easy part, usual autove type approach with a different map, however enabling it is a good question.
Im sure Ross can explain :)

[JezzaB]

Waiting for you to try it first Steve ;)

Havent had an E38 with a cam yet to have a crack at it. Was talking about it the other day and came up with a few ideas to try with it but nothing in stone.

But are the VE figures in LS2 (8192 max) type figures or the VVE style?


Jez

[oztracktuning]

Its looks like its already activated. But the table has all zeros. Its not clear what is needed to be done to get it going. I would want to use it just at zeo % throttle to start with just to smooth idle out.

[ntae]

i spent a few hours on it & had no luck

but in saying that i can't work out how to map the min air flow table

[ringram]

Min idle airflow table doesnt seem to work for static idle. See my other post re idle speeds. I dropped it into the ground, no change. The desired idle speed also only seems to work at rolling idle when over the 6kmph trigger.

I think some more work on the .calz files is in order :)

[GMPX]

Yes, even with 500+ calibrations there is still more to discover for these ECM's, The throttle VE's 'should' be active I agree, they are actually meant to be used when the cams are moving, obviously on many engine that will never happen, maybe a patch is in order to force them. But, as yet there has not really been the need for them.

Cheers,
Ross

[hymey]

Steve you could try enabling open loop, then use B0143 to command a richer idle. B0143 is only activated clutch in or neutral so it allows you to smooth out bigger cams at idle.

[Delco]

Throttle VE works perfectly , finally got around to testing it today Ross , did a log to calculate the VE from the speed density VE table , transfered it all across and it is was tracking within 2 % on the first pass , did some logging with it active and speed density inactive and it responds as expected , logged the ben factors and TPS VE is now spot on after a few passes over each load point on the dyno , recjhecked on the road and all is spot on.

It is active above a TPS setting and above the vcuum setting.

Cant see it being needed as yet as we have been able to get very big cammed combo's to perfectly and drive spot on using the VVE tables.

the E38 is a lot easier to tune with than the older PCM's

[hymey]

It is good to see someone has made progress here, The cammed VEs I have been in have all run very smooth still with closed loop enabled. The VVE table doesnt have the precise adjustment like the older version though to change an individual cell and prevent afrs from oscillating in zone 30 is hard, the VVE appears very smooth to look at but doesn't perform this way especially noticed in higher rpms when switching between cells. The system may allow smoother idle running, but I ask this question. Does the throttle table allow more steady top end afrs. With a lot of hours of road testing(including a 2000km straight log) there is afr swing evident. A customer may not pick it up in his own car that has been dynotuned, but the swing is definately there. The IAT flow table isnt fine enough in adjustment to combat. The VVE can be sorted with a bit of work, but its the WOT swing I am concerned about.

[Delco]

It is good to see someone has made progress here, The cammed VEs I have been in have all run very smooth still with closed loop enabled. The VVE table doesnt have the precise adjustment like the older version though to change an individual cell and prevent afrs from oscillating in zone 30 is hard, the VVE appears very smooth to look at but doesn't perform this way especially noticed in higher rpms when switching between cells. The system may allow smoother idle running, but I ask this question. Does the throttle table allow more steady top end afrs. With a lot of hours of road testing(including a 2000km straight log) there is afr swing evident. A customer may not pick it up in his own car that has been dynotuned, but the swing is definately there. The IAT flow table isnt fine enough in adjustment to combat. The VVE can be sorted with a bit of work, but its the WOT swing I am concerned about.

The IAT compensation table is infintely adjustable , the pcm interpolates between points , its just a matter of getting the values adjusted correctly rather than 2 or 3 variables changing your result , the VVE tables can be got very accurate but it takes a lot of effort and will be very hard to do with a wideband that has its own temerature swings , the Autronic wideband doesnt have anywhere near the swing of the tech edge/plx/lc1 etc due to its more accurate control.


No WOT swing evident her on the dyno or on the road on my own test car.

[hymey]

There is no argument that the Autronic is superior to the cheaper brands but with my consistent data proves its more to it than what most people believe.And my table is tuned as accurate as it will get(Many values change when you may only change one cell). Not saying your tune is out. But the IAT sensor can only be adjusted in 10deg increments, for some this is OK, but not accurate enough for perfection. My afrs also changed dramatically when I drove through Northern NSW though high altitude. Even if the cheaper brands have minor errors, I have yet to see any in tuned LS1s with a VE table that looks more like corregated iron(exaggerated) than the smooth e38 VVE that displays slight inconsistantcies throughout the MAP. It cant be perfect as it is only outcome from a mathematical formula that changes dramatically when only one cell is altered. Not a great deal, but there are flaws, after all the system was designed as a MAF/MAP hybrid. And we are only at the beginning of what can be achieved.

One last question is your autronic sensor an older style 4 wire LSM-II or later design(like a LSU4.9). The older sensors, while reliable are slower and not as accurate as the later model sensors.

[Delco]

Throttle VE (alpha N )is no where near as consistant as the map VE ( Speed Density) as you can have the same tps with different map values , there also appears to be VE compensation table B8003 interacting heavily with B8033 due to the transients.

Alpha N on the GenIII PCM was always inconsistant due to the same reasond , we only ever used it on huge cams and then reverted to speed density at higher rpm points.

[GMPX]

Thanks for testing that Delco, seems I got the descriptions wrong. The light globe turned on when I looked at a E67 V6 file that has the tables active and saw what GM had done to make them work, rechecked the logic of the code and gave Delco a call and said can you try these settings please!
Well, that's a load off, no custom OS needed for Alpha-N......thanks GM and easily tunable to revert between Alpha-N and SD mode whenever you want.
With the LS1 Alpha-N COS, that was really just for engines with trumpet type manifolds were MAP was pretty much 95-100kPa all the time from idle to WOT.

Cheers,
Ross

[ringram]

Excellent, I see now that there are a few more things in the latest BBL cals for this.

BTW: Has anyone played with the Dynamics stuff, "Stomp Compensation vs IVT"?

Oz looks like this is your pump shot!?

[GMPX]

I got a call from OzTrack on Friday to say the Dynamics stuff was doing it's thing.

Cheers,
Ross