VVE Assistant.exe

I am going to start a new thread here for the VVE tool I created. We had a good thread going (well we hi-jacked LSxpwrdZ's thread) in the Support > Editor area, and since that really wasn't the right place for it, I decided it was time to move it out and have a dedicated spot for the tool. It really belongs in both Gen 4 and Gen 5 sections though.

I made a more complete walk-though video here (and still manage to leave out a bunch of stuff I wanted to talk about):
https://youtu.be/_Eiyy460C_k

The video description contains the link to download it. Just copy the EXE and DLL into the same folder and away you go!


Note: video is uploaded but the HD processing is slow...so maybe give it a little time...

A moderator should copy the relevant parts of that thread to here if possible

perfect I'll be supporting you

Great tool.

Let me give you some precious bits of information from inside of the ECM.
1. Intake and Exhaust Cam Positions in VVE model is really CRANK referenced angles. So limiting Cam angle to 20* (just like HPT) you are restricting real Cam position to 10* which is hilarious.
2. Gen4/Gen5 ECM internal Cam position range is 32* (or 64* CRANK).

To get rid of steps on zone border crossing you can use 'Zone Overlapping' when calculating coefficients. The Idea is to use narrow strips of adjacent zones data (for example 5kPa/100RPM wide or just one table cell) as addition to current zone.
I'm doing so in my own VVE tool and it gives extraordinary smooth surface.

Quote:

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Originally Posted by verlon

Great tool.

Let me give you some precious bits of information from inside of the ECM.
1. Intake and Exhaust Cam Positions in VVE model is really CRANK referenced angles. So limiting Cam angle to 20* (just like HPT) you are restricting real Cam position to 10* which is hilarious.
2. Gen4/Gen5 ECM internal Cam position range is 32* (or 64* CRANK).

To get rid of steps on zone border crossing you can use 'Zone Overlapping' when calculating coefficients. The Idea is to use narrow strips of adjacent zones data (for example 5kPa/100RPM wide or just one table cell) as addition to current zone.
I'm doing so in my own VVE tool and it gives extraordinary smooth surface.

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Huh interesting about the 20 vs 32 degrees. Glad I don't have to mess with on my LS3 lol! I suppose I should allow the tool to go up to 32*...if you log the cam angle in the scanner does it show 32* when maxed out? I wonder why HPT limited it to 20*?

So will this work with a 2 bar OS and VE instead of VVE? Obviously you would need to flip axis and still input zones.

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Originally Posted by Cringer

I suppose I should allow the tool to go up to 32*

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I'd say twice, up to 64*

Quote:

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Originally Posted by Cringer

if you log the cam angle in the scanner does it show 32* when maxed out?

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Very likely it will. I've seen 28.5* in my L94.

Quote:

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Originally Posted by Cringer

I wonder why HPT limited it to 20*?

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Don't know for sure, but I know only one VVT engine with cams not exceeding 20*, it is LH2 Northstar.
Perfaps it was the first VVT engine with Delco ECM which was reverse engineered by HPT and later used to develop VVE tool.

Quote:

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Originally Posted by ttz06vette

So will this work with a 2 bar OS and VE instead of VVE? Obviously you would need to flip axis and still input zones.

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I haven't tested it with this config. Most likely it would need some tweaks to pull it off. I will add it to my roadmap though.

Quote:

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Originally Posted by ttz06vette

So will this work with a 2 bar OS and VE instead of VVE? Obviously you would need to flip axis and still input zones.

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The main tool works with any table you can put into it. I often use it for averaging fuel density logs or MAF logs for best data corrections.

Quote:

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Originally Posted by verlon

Great tool.

Let me give you some precious bits of information from inside of the ECM.
1. Intake and Exhaust Cam Positions in VVE model is really CRANK referenced angles. So limiting Cam angle to 20* (just like HPT) you are restricting real Cam position to 10* which is hilarious.
2. Gen4/Gen5 ECM internal Cam position range is 32* (or 64* CRANK).

To get rid of steps on zone border crossing you can use 'Zone Overlapping' when calculating coefficients. The Idea is to use narrow strips of adjacent zones data (for example 5kPa/100RPM wide or just one table cell) as addition to current zone.
I'm doing so in my own VVE tool and it gives extraordinary smooth surface.

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You can confirm that it's crank angle and not cam angle? I just thought I was having trouble getting the cam tables right because I was having to adjust the coefficients - didn't realize it was just because I was looking at it completely wrong altogether. What are you logging to show this? I've always just logged cam angle.

Quote:

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Originally Posted by GHuggins

You can confirm that it's crank angle and not cam angle? I just thought I was having trouble getting the cam tables right because I was having to adjust the coefficients - didn't realize it was just because I was looking at it completely wrong altogether. What are you logging to show this? I've always just logged cam angle.

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I confirm it's crank. Was having same troubles and started digging how VVE is really calculated is the OS.
There is nothing to log to show this, but it's true.

Quote:

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Originally Posted by verlon

I confirm it's crank. Was having same troubles and started digging how VVE is really calculated is the OS.
There is nothing to log to show this, but it's true.

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Are the camshaft angles in the VVE tables always crank degrees or does it depend on the ECU? For the LFX (3.6 V6) the cams are adjusted in camshaft degrees, 0 - 25, but I believe on the LLT (previous generation V6, different ECU) the cams are adjusted in crank degrees (50 degrees of movement as opposed to 25: 7 to -43 on intake, 15 to 65 on exhaust). The VVE tables on the LFX let you choose 0 - 20 but not sure about the LLT, however.

Quote:

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Originally Posted by verlon

I confirm it's crank. Was having same troubles and started digging how VVE is really calculated is the OS.
There is nothing to log to show this, but it's true.

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So lets say you're adjusting fueling for a 5 degree cam angle - do you then adjust the 10 degree VVE table or rather use that positions air model for adjustment?

Quote:

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Originally Posted by GHuggins

So lets say you're adjusting fueling for a 5 degree cam angle - do you then adjust the 10 degree VVE table

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exactly

Explains why I've always felt like I was chasing my tail and not adjusting the right thing - because apparently I wasn't :banghead:

Not sure if you're interested, but perhaps you and cringer could work together to make the "ultimate" tool :) He's buttoning up some more enhancements on it right now, but I know your help on the VVE side could be beneficial ;)

Ok, we have a complication. Thanks to KillboyPowerhead I had to doublecheck for E39 and then went to E92 :)
E38/E67 uses crank angle in VVE
E39/E92 uses cam angle in VVE
Seems like tool must have a switch to select angle reference.

Quote:

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Originally Posted by GHuggins

Not sure if you're interested, but perhaps you and cringer could work together to make the "ultimate" tool :) He's buttoning up some more enhancements on it right now, but I know your help on the VVE side could be beneficial ;)

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We can try. I'll be glad to participate.

Hoping that's the case for the LFX (E39A ECU) or else 0 - 10 cam degrees would be pretty limiting (although the fact that the tables only go to 20 is still limiting, if you go past 20). Wonder why 20 is the limit... seems arbitrary.

I guess to test/prove a particular ECU (and tune the VVT in general) you would dial in the whole VVE base table (with the cam(s) set to 0 degrees, since all tables use these coefficients), then adjust the cams as desired, then see how the VE Airflow (or whatever is your tuning method of choice) compares to the VVE tables for those cam degrees? So if you set the cam(s) to 10 degrees for example, then adjust the coefficients to get the 10 degree VVE table to match VE Airflow, after retesting you should see that VE Airflow matches; if not then redo for the 20 degree table and see if you get a match? Hopefully I explained that coherently...

I also noticed in my own testing that when changing coefficients for one particular set of cam degrees (DOHC in my case) it can make another combination of cams off more than it was before (for example, you dial in intake = 9 and exhaust = 9, but now intake = 6 and exhaust = 6 is further off than before), and since changing the coefficients affects those particular zones on all tables there appears to be a compromise to make... Guess once you have the cams set the way you want then you can dial in those particular combos until the overall difference/error between all of the tables is at a minimum (and I guess you really only need to make sure under 4000 RPM is accurate since the MAF will be mostly used otherwise?).

FYI here is the formula for DOHC engines:

[Constant]+([MAP]*MAP)+([MAP^2]*MAP^2)+([MAP*RPM]*MAP*RPM)+([MAP_Intake]*Intake*MAP)+([MAP_Exhaust]*Exhaust*MAP)+([RPM]*RPM)+([RPM^2]*RPM^2)+([RPM_Intake]*Intake*RPM)+([RPM_Exhaust]*Exhaust*RPM)+([Intake]*Intake)+([Intake^2]*Intake^2)+([Exhaust]*Exhaust)+([Exhaust^2]*Exhaust^2)+([Intake_Exhaust]*Intake*Exhaust) = VVE cell value

Where:
Square brackets = value in that coefficient table
MAP = MAP value (row axis) in VVE table
RPM = RPM value (column axis) in VVE table
Intake = intake cam angle selected in VVE table
Exhaust = exhaust cam angle selected in VVE table

Cringer posted the formula sans exhaust cam in his other thread but thought I'd post this here for anyone with a 4 or 6 cylinder. Found the formula by just throwing in numbers and seeing how the tables reacted. Easy enough to create a calculator in Excel to find the coefficients for a particular zone.

Quote:

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Originally Posted by KillboyPowerhead

Hoping that's the case for the LFX (E39A ECU) or else 0 - 10 cam degrees would be pretty limiting (although the fact that the tables only go to 20 is still limiting, if you go past 20). Wonder why 20 is the limit... seems arbitrary.

I guess to test/prove a particular ECU (and tune the VVT in general) you would dial in the whole VVE base table (with the cam(s) set to 0 degrees, since all tables use these coefficients), then adjust the cams as desired, then see how the VE Airflow (or whatever is your tuning method of choice) compares to the VVE tables for those cam degrees? So if you set the cam(s) to 10 degrees for example, then adjust the coefficients to get the 10 degree VVE table to match VE Airflow, after retesting you should see that VE Airflow matches; if not then redo for the 20 degree table and see if you get a match? Hopefully I explained that coherently...

I also noticed in my own testing that when changing coefficients for one particular set of cam degrees (DOHC in my case) it can make another combination of cams off more than it was before (for example, you dial in intake = 9 and exhaust = 9, but now intake = 6 and exhaust = 6 is further off than before), and since changing the coefficients affects those particular zones on all tables there appears to be a compromise to make... Guess once you have the cams set the way you want then you can dial in those particular combos until the overall difference/error between all of the tables is at a minimum (and I guess you really only need to make sure under 4000 RPM is accurate since the MAF will be mostly used otherwise?).

FYI here is the formula for DOHC engines:

[Constant]+([MAP]*MAP)+([MAP^2]*MAP^2)+([MAP*RPM]*MAP*RPM)+([MAP_Intake]*Intake*MAP)+([MAP_Exhaust]*Exhaust*MAP)+([RPM]*RPM)+([RPM^2]*RPM^2)+([RPM_Intake]*Intake*RPM)+([RPM_Exhaust]*Exhaust*RPM)+([Intake]*Intake)+([Intake^2]*Intake^2)+([Exhaust]*Exhaust)+([Exhaust^2]*Exhaust^2)+([Intake_Exhaust]*Intake*Exhaust) = VVE cell value

Where:
Square brackets = value in that coefficient table
MAP = MAP value (row axis) in VVE table
RPM = RPM value (column axis) in VVE table
Intake = intake cam angle selected in VVE table
Exhaust = exhaust cam angle selected in VVE table

Cringer posted the formula sans exhaust cam in his other thread but thought I'd post this here for anyone with a 4 or 6 cylinder. Found the formula by just throwing in numbers and seeing how the tables reacted. Easy enough to create a calculator in Excel to find the coefficients for a particular zone.

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Thank you! I may add the exhaust option in a future release!

Quote:

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Originally Posted by Cringer

Thank you! I may add the exhaust option in a future release!

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Do it! I have DOHC and would utilize it haha

Using the VVE Assistant tool, if I have a broad range of rich and lean in the same zone what is the best way to even it all out?

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