Tuning 02 Suburban 5.3 advice

[ScarabEpic22]

Hey guys, my girlfriend has an 02 Burb 5.3 bone stock that I want to tune a little for some extra mileage. (It still gets better mileage than my TBSS stock for stock though )

Havent tuned an LS1 PCM yet, glad I found one to play with! Dont really want to worry about adding a WBO2 because I wasnt planning on doing much WOT related stuff as it never gets driven hard. Thinking Id start with Shawn's Calc.VE tutorial and go from there, went through it and setup a base tune to start with (Calc VE Tune_0001). Ill adjust the trans a little as well, raise the line pressures and reduce TM a bit. Any ideas for a rough spark setup, Ill know more after I log it tomorrow but any advice is much appreciated. Going to stick with 87 octane too.

Mostly Im just looking for a little advice, Ive read the Calc.VE tutorial a few times but is there anything else I should do to the Burb before I start tuning it? Its fine mechanically, Ill double check tomorrow AM before I start tuning though just to double check.

Thanks guys!

(P.S. The VIN starts with 3GN so it comes up as a GM Light Truck - Mexico, does that mean it was made in Mexico or supposed to be sold in Mexico? Both of mine are 1GN made in the US)

[WeathermanShawn]

Seems like a pretty good base Tune, Erik.

If you run into any difficulties or need more information on CALC.VE, just let us know.

Sounds like a good 'project'. Are you going to modify it or just leave it stock?

[ScarabEpic22]

Went through the tune and played with the trans settings, used the settings from my 02 4L60E behind my regular 4.2L TrailBlazer as a reference. Cut TM by 50%, lowered the shift times by a little (copied performance mode params over to normal).

The biggest concern of mine is looking at the Fuel -> Mixture tables -> PE Modifier based on RPM. Super rich all around IMO, commanding 11.29 from 4800-7200 seems excessive. I think it WOT shifts around 5600-5700, so the last tables are irrelevant but even if the VE is messed up I think 11.3:1 is waaaay rich. Hope once I get the VE and MAF dialed in I can adjust this to like 12.4-12.8:1. Thoughts on this?

Glad it already has the 12212156 OS so I dont have to full flash it, going to do this one completely via BBx too, have an AutoCal itching to be used.


Shawn beat me to it! I will, its going to stay stock as this summer she'll be driving it back down to her home in San Francisco from Spokane, WA. Has to return it to her parents and buy her own car (trying to get her to stick with GM, but might have to go with something else cheaper). She's being awesome and indulging my want to tune a LS1 PCM! Wish I could slap my LC-1 on it and really get the WOT dialed in, but thats not really that important to her (plus something's screwy with mine, V2 reports like 4-5:1 AFR right now but I dont have a PC with a serial port to talk to it) . Heck Ill probably have to force her to put her foot all the way down tomorrow!

[WeathermanShawn]

Yea, I guess I did notice that PE Fueling being on the rich side...

Even an EQ of 1.16-1.18 would be pretty decent. Safe, but near optimum AFR/EQ.

I guess you have to ponder B3601 and whether to take it to E10 or whatever type of gas you guys have there. Are you going to keep B0701 Enabled? That will keep you pretty rich too. Disabling may not be a bad idea..

[ScarabEpic22]

I was, here all we have is E10 so the I did the math based on both 14.68 and 14.07 (E10), still comes out to being super rich. I havent disabled cat protection before, going to leave it enabled on my TBSS until I go catless. I want to make sure this thing doesnt have an issue, its different tuning this vs a customer's truck that knows what to do and what not to do. Her parents dont know or care about cars so Im keeping this in mind when tuning it. I know cat protection seriously goes rich when active, I dont want them to burn up the cats if they ever drive it hard for a while. Whats your opinion?

[WeathermanShawn]

I think Cat Protection goes to a 1.25 EQ. Like you said it all depends on the 'user'. My personal opinion is that Disabling is not an issue unless you do 2-3+ WOT runs back to back. That will get your cats pretty hot.

If you were really going to hook up a WB etc..then yes Disable, otherwise its a judgment call. Maybe just tune PE to the same EQ?

Have fun on it..

[nathans1987]

Who cares about cats unless you need an emissions test? turn it off.

[ScarabEpic22]

OK so Ive been running around with this tune (Calc VE_0004) in it for about a week now. Have the trans shifting how I like it, playing with a little more PE stuff in this latest tune (Calc VE_0005).

Took Shawn's advice and played with the PE modifier based on RPMs, set it closer to what it should be and not pig rich like from the factory. Dont want to go too lean as there's no WBO2 on this truck.

Mostly Im looking for any and all suggestions about what the optimal spark setup should be, any ideas? Just subtracted a tiny bit of timing in one spot where I was getting knock, but I think there's more to be had.

[WeathermanShawn]

Erik, it looks like a very well-constructed Spark Map(s) to me.

I guess that vehicle/set-up can tolerate more spark advance at lower RPM's/Cylinder Air than I am used to seeing...

[ScarabEpic22]

I think its the truck intake, the tunes for my LS2 in the TBSS run more advance than the Vette/GTO LS2s I believe.

I havent touched the spark maps Shawn, just pulled a tad bit of timing where I got some knock. Wish I had a dyno, I could pound the spark out in an hour or 2. But if I was going to throw $$ at a dyno, I might as well drop a WB in it too...slippery slope ha!

I dont want to just throw x degrees more of timing at it then watch for knock, but is there anything else I can do right now? I might start with mirroring the high octane table into the low to see if it can run the high octane without knock. If it can then Ill subtract a few degrees to be safe (in case of crap gas) in the low octane table and call it good.