Convert config from 5.3 to 6.0

[weinerschizel]

I built a 6.0 LQ9 after I shot a rod through side of my 5.3L. I used some of my parts and some 6.0L parts I came by to build it. Now I need to reconfigure the computer from the 5.3L to run the 6.0L. Right now I'm looking at a 2005 LQ9 from Silverado SS. I believe it also has the 4L60E.

So what parts of the Silverado SS / LQ9 configuration should I look at copying over to my old 5.3 configuration?

Bit more on my build. Note this is a 2001 gen 3 setup in Z71 Tahoe I'm working with.

- LQ9 bottom end balanced to within 1 gram.
- Vinci performance camshaft 578/587/213/220/114+4A
- Dual Valve springs to match cam
- Johnson 2116LSR lifters with custom pushrods from Manton
- Cleaned up castings / 317 heads otherwise stock.
- Intake manifold and throttle body from 2001 5.3L w/ factory 24 lb injectors
- Stock exhaust
- Stock 4L60E and converter

Will be building a 4L60E w/ 5 pinon planetary, upgraded shells, stronger clutches, shift kit etc. For now running factory transmission though. I may want to dial back power on shifts or do something to preserve the transmission till I can get the new one built.

Build is a low end grunt / torque motor and not so much a peak horsepower machine. My first startup video below using 5.3L factory tune:

https://vimeo.com/manage/videos/538184039

[Ruszkowski]

I may be able to help but I am in a similar situation, went from a LS1 to a 030 bored and stroked LQ9, all that i have changed so far was the cylinder volume, to reflect my new 6.5 liter, then I added 25% fuel to the VE table and pulled 2 degrees of timing just for safety as this is a new motor. From there you'll definetly need a tune to get the most out of the new motor. I hope this helps.

[5FDP]

Rusz, you engine isn't 25% larger so you don't need 25% more fuel. It's going to be really rich just so you know.


To the OP, you need larger injectors, the stock 25lb/hr won't support a 6.0 with a camshaft upgrade. Find larger ones from a flex fuel truck or source something else, FF injectors are 33lb/hr.

It'll start and run ok. It may need a little bit of fuel added to the MAF/VE if the fuel trims are showing lean or your wideband is showing lean. Likely needs some base running airflow too. Also adjust the idle timing so it's around 18-22 degrees and adjust the over/underspeed spark correction tables so they are around +/- 8 to 10 degrees. Many stock files are like 15 to 30 degrees and you don't want that much swing.

[weinerschizel]

@5FDP Ah shoooooot haha. I just bought the 24 lb fuel injectors. My old ones were broken, which blew my motor. I had thought about the larger injectors but sprung on these when I got a good deal. The stock LQ9 / 6.0 seemed to call the same part number as the LM7 / 5.3. They must be nearly maxed out? I was a bit worried about this but didn't have much guidance on my build.

I did fire it up today on the 5.3L tune. I didn't like to run so much, ran a few seconds then died. I need to get my wideband wired in. I put the bung in the exhaust, just need to hook up all the wiring harness and data logging now. Then I'll start fiddling around with what you suggested

@Ruszkowski thanks for the pointers. I'm going to tune it myself with wideband. Just pretty rusty. Last time I tuned was with TunerCat on OBD I nearly 20 hears ago haha. Bought all the HP tuners stuff to do a blower on my LS1 but never did it. Now I built this 6.0 and it's getting put to use.

[Ruszkowski]

5FDP, Thank you, Just wanted to be safe.

[2xLS1]

I may be able to help but I am in a similar situation, went from a LS1 to a 030 bored and stroked LQ9, all that i have changed so far was the cylinder volume, to reflect my new 6.5 liter, then I added 25% fuel to the VE table and pulled 2 degrees of timing just for safety as this is a new motor. From there you'll definetly need a tune to get the most out of the new motor. I hope this helps.

And a .030 over 6.0L is not a 6.5L. It is a 6.05L.

[weinerschizel]

Perhaps somebody could help me shed light on this. I have a VCM recording but not sure how to attach it? I am tuning with a P01 computer from 2001 Tahoe.

The tune I'm running, has turned off Speed Density and O2 feedback. I'm working with the MAFS only, to calibrate it first. Otherwise so far as I know is a stock 5.3L bin with Engine-> general changed to 6.0L and 0.7500 for cylinder volume per 6.0L (although no telling what former owners did with truck).

When I start the engine (no throttle) the computer seems to be entering power enrichment mode? The computer reports that it is commanding an AFR of 12:1.

Any clue why this might be?

Also, I presume it's standard AFR command would be around 14:1, for just slightly on side of rich?

I'm a nube so take it easy on me haha

[5FDP]

Engines start in open loop so it's going to look at the open loop EQ ratio for a commanded fueling value.

Engines don't like to start at stoich (14.1-14.7) when they are 60 degrees. They need more fuel at cold temps to start/run easier while warming up.

[weinerschizel]

Engines start in open loop so it's going to look at the open loop EQ ratio for a commanded fueling value.

Engines don't like to start at stoich (14.1-14.7) when they are 60 degrees. They need more fuel at cold temps to start/run easier while warming up.

Oh that makes since. My WB O2 burned out so I just installed a new one yesterday and fiddled around some more. I noticed the engine was running around 14:1 then. I think part of the issue sounds like the ambient air temperature sensor. Mine broke, I'll need to install a new one. Typically it's much warmer than 60F here.

Having some confusion setting up the Custom Math Parameters. I read in MVPI Pro Analog 1 and convert it to AEM 4110 WB reading on channels list. Then I try to do the math parameter so I can make calibration charts with the WB corrections. I'm doing a user defined math parameter to convert analog 1 to WB Air Fuel Ratio and calculate it's error off commanded AFR. I'm not having a lot of luck. Here's a video of me trying to set it up.

https://drive.google.com/file/d/10Wu...ew?usp=sharing

[weinerschizel]

Rusz, you engine isn't 25% larger so you don't need 25% more fuel. It's going to be really rich just so you know.


To the OP, you need larger injectors, the stock 25lb/hr won't support a 6.0 with a camshaft upgrade. Find larger ones from a flex fuel truck or source something else, FF injectors are 33lb/hr.

It'll start and run ok. It may need a little bit of fuel added to the MAF/VE if the fuel trims are showing lean or your wideband is showing lean. Likely needs some base running airflow too. Also adjust the idle timing so it's around 18-22 degrees and adjust the over/underspeed spark correction tables so they are around +/- 8 to 10 degrees. Many stock files are like 15 to 30 degrees and you don't want that much swing.

I cheated and got the truck running by bumping idle up to 900 RPM across the chart for Engine->Idle->RPM->Base Setpoint. Then I took Engine->Spark->Advance->Idle Spark Advance->In Drive. Set the table from (0rpm, 0.08g) to (1200rpm, 0.28g) to 25 degrees. (Found in Youtube tutorial)

I wonder if all that advance in idle table could be messing up my spark tuning?

I found the Idle Adaptive Spark Control Overspeed & Under speed per your advice. I assume I just multiple by a scalar to get those within the +/- 10 degrees? Then I can tune my idle properly and set it back down to what it was before.