LS3 Swapped Silverado

[jnnewton]

I purchased the older mpvi pro second hand a while back, and used it to disable the DoD on my truck (2012 silverado w5.3L flex fuel LMG) and change the torque limiting a bit in my truck. Ran good for a while, and then started burning oil like crazy and the repair costs were more than I wanted to throw at that motor with it's mileage. Long story short: it's getting a new motor and exhaust. I should have it in sometime in the next week or two (it's an LS3 from a 08 corvette). I have the harness, fuse box, computer, motor, all the accessories, but not the gas pedal.

Both are e38 computers. I need to figure out what I need to do once the mechanical parts are all done. I am using the harness from the truck as it sits, and the pedal, and am hoping all the sensors on the new motor are compatible with the harness in the truck because the one from the vette is in pretty rough shape and the truck wiring is pristine.

So do I:
A - Pull a stock tune file from the repository here and load it in my truck computer.
or
B - Swap the ecu from the vette into the truck.

And what other steps or problems will the suggested course of action require?

[5FDP]

Copy and paste data into your trucks computer. Flashing something else in could brick it or render your transmission unless with the new calibration.

It's going be all custom to this application anyway so starting off close enough should be alright to get you going. Make sure the main few things are good like timing, fuel injector data and so on. You'll be need to MAF tune and VVE tune it for the swap to truly dial in the airflow model with a wideband o2 sensor.

Most of the harness stuff should be pretty close. I know the MAP sensor data is different from 2008 to 2012 and the pins in the harness might be too. If possible just use your truck MAP sensor in the LS3 intake.

[jnnewton]

5FDP: Thanks for responding. I'm using a rectangular port truck intake from I believe a 2008 escalade. It seems to mate properly to the ls3 heads and ls3 TB, and puts it in the proper place to meet my trucks intake pipe(stock) from the airbox (stock). This means I can use both the MAP and MAF from the truck. I am using the injectors from the LS3 and got a fuel rail that fits the new manifold and the shorter LS3 injectors. Everything else I can think of is from the truck. It sounds like I need to do the following:

1. Power the corvette ecu somehow, I can probably figure this out if i can find a schematic.
2. Buy a credit for hp tuners so i can read the corvette ecu (or can I just read without needing a credit)?
3. Hook the hp tuners up to it and read the ecu and save as a file (motor data).
4. Open the read file and find a timing table, a fuel injector data table (and others?).
5. Close that out, connect to my truck, and put the numbers from those two tables (and others?) into the same tables in the truck.

That should get me close to stock enough to drive regularly, but if i want it dialed in for performance (which I don't necessarily need at this point) then I need to purchase a wideband and learn how to tune it.

I know I just reworded some of your info differently, but they way you put it makes it sound very easy, and I want to make sure I'm not missing anything (like tables other than the two you list prior to "and so on").

[5FDP]

Reading files is free, only when you want to license a file does it cost you credits. So you only need to license your trucks computer only, this way you can save changes to it and flash the changes into the computer.


Now that you said you are going to run a escalade truck intake on this 6.2 car engine, it makes it even easier at least in my eyes to get you going.

Use the tune repository on your customer page. From there you can look up both a stock corvette file and a stock 6.2 truck file. If you are going to run the corvette injectors, then you'd need to copy that data over. If your truck was factory flex fuel, then I'd suggest keeping your stock injectors and changing nothing. They should already be like 38lb/hr injectors and should provide enough fuel for a stock LS3 engine.

Or if the 6.2 intake comes with injectors, use those as they are even bigger if I recall correctly. That too would just need the data copied over.


As far as the engine data is concerned, I'd basically do a copy/paste with a 6.2 truck data as that would get you pretty darn close for a starting point. You can open your 5.3 truck file and the 6.2 file using the compare feature in the editor, then use the compare feature to copy all the data over in a few clicks of the mouse.

[jnnewton]

Thank you. I didn't even think about going that route.
I have the stock LMG flex fuel injectors: 36 lbs/hr @ 43.5 PSI and the stock LS3 Injectors: 41 or 42 lbs/hr @ ?? from what I can find. I don't have any injectors from a 6.2 truck. I just got the intake and a fuel rail that has the longer cups to reach the LS3 injectors. I'd hate to run out of fuel and may never, but would like to go ahead use the LS3 injectors since I have them. I like your plan of attack, I'll get going on this in a week or two and hopefully can post 4 files on here: my lmg (for things that , a stock 6.2 truck (for most everything) I find, a stock ls3 i find (for injector data) and the file I plan to use to start the engine. I would appreciate a review of my first try before I try cranking the engine as it's my first LS swap and I'd hate to damage something due to my ignorance.

[jnnewton]

Here the files I used, and my working tune I want / plan to try. I mostly chose to copy over values from a corvette file (maybe the cam is different from vette to truck or maybe the valvetrain differences could cause some differences. Can you take a look at these and see if I'm ready to give it a go or anywhere I can make improvements prior to running and getting a log. It won't run very well at all on my 5.3 tune at all, idles rough, wants to fall on its face when letting off the throttle at a stop sign and generally sounds "rough". Also developed some smoke and a few backfires, but when I re loaded the file, it went away, so maybe it's building the LTFTs incorrectly with the current file.