Chevy Cruze SD Tuning Question

Hello,

I am new to tuning and have a couple of questions about tuning my Cruze. I read the write up in the help section in regards to the E78 ECM and understand that it correlates power by torque requests. However, I have done an intake and exhaust on my Cruze and from my understanding, wouldn't I need to remodel my airflow in a sense due to my change of intake?

I have been doing a lot of research on Speed Density tuning, and think that correcting the VE table (Based on AFR Error) would be the right route to take. However after doing some more reading up around the forum and on my VCM editor I can't exactly find the VE Table I am looking for.

I may be approaching this the wrong way, but I really want to do it the RIGHT way! If somebody could point me in the right direction I would appreciate it a lot, as I have a lot to learn and want to get it done correctly.

THANKS!

you have to use the virtual ve software built into the editor. as long as it hasn't been moved it should be listed under the edit tab in the vcm editor.
the software will allow you to build a fake ve table based on on a default axis....iirc its based on an ls1? dont quote me on that though. If your sensors are all factory use the standard 2.5 bar or equivalent axis model. if you decide to define the axis with custom numbers hen wait for the proper model to update then set your scanner to match its axis.
you can then adjust the virtual table as if it was active just like the videos and write-ups you have already combed through. after making your tuning adjustments to the model, click the send information to ecu button and it will auto adjust the necessary tables in the editor to make the changes happen for you.
if that wasn't clear enough i would search for more information on "bluecats virtual ve tool" or "virtual ve" in general.

Thanks for the reply! I did read up on this kind of virtual VE table, but wasn't sure if it would pertain to my Cruze. I remember Chris talking about some of the factors that build the VE table for these types of cars, but it was kind of over my head. Anyways, I found what I was looking for, Thanks for pointing me in the right direction!

if you run the 1.4t ecu with Virtual VE then the Maf is already turned off from the factory. The activation limit is set so high it never really uses it. The biggest thing with the maf sensor is the IAT. If you unplugged it and deleted the codes then you actually removed the IAT scaling control section from Virtual VE.
Best thing to do on the 1.4t ecu is to pull the MAf signal wire out of the housing and leave the rest plugged in. fold it over itself and put a little bit of shrink wrap over it and tuck it into the harness so it looks like it was never there to start.
In order to tune idle and cruise you do not need your wideband unit. the virtual ve is set to be adjusted via fuel trims off the factory unit which is the recommended method of tuning everything but wot as your wideband doesnt always match the ecu's trim error and causes tail chasing in the lower load tuning sectors.

unfortunately i dont have any time to dive into the depths of this style ecu. im currently tied up on a custom chassis and a supra ecu disaster. I hope what i offered helps a little bit.

I own a 1.4t Cruze myself as well as tuned a couple other ones and I was always very intrigued as to why GM set the car/tune up this way. Have the MAF in place and working but have it basically just running speed density. A little odd to me after dealing with all the different pcms and operating systems over the years and what I am used to seeing the way GM sets up the tunes from the factory.

Cobalt guy is right, we don't have a VE table per say ... If you look in the Airflow tab at the 'constants'. Those are what the Virtual VE table is derived from.

I have looked at this and decided against doing any VE tuning. It's way to ambitious for my purpose. The variable cams will play a HUGE role in this. You will have a different table for every intake a exhaust cam degree. So ... one table for 1* intake / 1* exhaust, it changes for 1*/2*, 1*/3*, all the way to what ... 1*/28*, then we can start over on 2*/1* - 2*/28* and so on and so forth all the way up to 28* on the intake cam and 28* on the exhaust cam. So .. in the end a possible 784 different virtual VE tables?

No thanks. :)

you didnt understand my post... the maf is disabled form factory. it is running in SD the day it leaves the assembly line

the only thing the ecu could be doing is a background data verify. It is in SD mode from the factory floor which means the maf has no priority on the output equation unless you were to say lower the rpm activation point.
im not trying to stir you up just stating with the maf not active that it falls under the classification of Speed Density.

Ran the car at SCCA SOLO Nationals last week. First day was 95 degrees, IAT in the 110+ range, and the Intake Manifold temps were in the 130-140 range. Power seems much lower than on cooler days. this seems to be typical for SD tunes. I will turn the MAF back on and adjust the MAF till it is as correct as possible.

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Originally Posted by cobaltssoverbooster

you didnt understand my post... the maf is disabled form factory. it is running in SD the day it leaves the assembly line

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Oh, I do understand your post. but you are not correct.
The iron block 1.4 uses a blend of MAF and VVE. The MAF is not disabled from the factory. At least not in my understanding.
The factory VVE covers every possible rpm, load, temperature the stock set up would normally get into. 400--8200 RPM, and .30 to 3.0 pressure ratio. That's why you can set the MAF engage and disengage points so it "fails" with the error code and turns the running over to the VVE/SD. ANY change you make to the stock set up that changes the airflow through the engine will require changes to the VVE. With HPT 4.4.4 the VVE corrections are quite simple, if you understand and follow the directions. The tricky part is to use Averages and Copy by 1/2. Watch Goat Rope Garage about SD tuning on the group 4&5 GM ECM's.


Del Long

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Originally Posted by sprinto7

Oh, I do understand your post. but you are not correct.
The iron block 1.4 uses a blend of MAF and VVE. The MAF is not disabled from the factory. At least not in my understanding.
The factory VVE covers every possible rpm, load, temperature the stock set up would normally get into. 400--8200 RPM, and .30 to 3.0 pressure ratio. That's why you can set the MAF engage and disengage points so it "fails" with the error code and turns the running over to the VVE/SD. ANY change you make to the stock set up that changes the airflow through the engine will require changes to the VVE. With HPT 4.4.4 the VVE corrections are quite simple, if you understand and follow the directions. The tricky part is to use Averages and Copy by 1/2. Watch Goat Rope Garage about SD tuning on the group 4&5 GM ECM's.


Del Long

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Thanks for the tip on Goat Rope Garage. I hadn't come across that channel yet which surprised me but it has filled in a lot of the blanks I had. Super helpful. I actually just signed up on his patreon for the one on one hour session. I'm really looking forward to it.

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Originally Posted by LittleBlue

Thanks for the tip on Goat Rope Garage. I hadn't come across that channel yet which surprised me but it has filled in a lot of the blanks I had. Super helpful. I actually just signed up on his patreon for the one on one hour session. I'm really looking forward to it.

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Let us know how that comes out.

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Originally Posted by sprinto7

Let us know how that comes out.

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I had my first one hour session this morning and it was very informative. The session is also recorded so you can review the information later. We covered smoothing VVe table adjustments, VVe zones, and virtual torque adjustments. I definitely would recommend doing the one on one if you have unanswered questions.