Tuning assistance on my 08 5.3 silverado

[icemanjc1]

While I do enjoy and have had great results tuning Cummins and Duramax, I can't get a good handle on my gas motor. So I could use some help.

I purchased a 2008 Chevy Silverado 1500 crew cab 4x4 5.3 (E38) flex fuel back in April of this year. Since then I have installed tri-y headers (fabbed in high flow cats) with all 4 stock O2s, free flowing exhaust, performance oriented rebuilt transmission with 2000 rpm stall converter. Only engine work I've done was replace the camshaft (mild Comp truck cam) due premature failure of the stocker and to also mechanically be rid of the AFM crap.

Any help would be appreciated.

[joecar]

Have a read of the E38/E67 VVE Tutorial and Guide...

http://forum.efilive.com/showthread....VE-Setup-Guide

post #68 contains a link to both documents.

[icemanjc1]

Thanks for that, lots of info there. My question is, are wide band O2s a must to use the VVE setup guide?

[Wheelz]

It is highly recommended. It cost around $200 to get a serial WB. I recommend the innovative LC-1

[icemanjc1]

$200 for for the kit and sensor, but wouldn't I need 2 of them? Or do you just put it after the Y pipe and you're good?

[Wheelz]

$200 for the sensor and sender. All you need to make it work with your V2 is a null modem db9 adapter, or build your own 3/16 stereo to RJ-12 serial cable (that's what I did) there are instructions around here that explain that part better. Ill look them up.

And you only need the one sensor. You only have one VE table and one MAF calibration, along with the geometry being identical between banks, so one sensor works just fine. Some people use 2 but they are a minority.

You have a couple options for installation. A) add an exhaust bung for the WB sensor before the cat but after the collector on the header. This will let you run all your sensors like stock. Or B) which is what I did for now (I have tri-y headers in the garage. I just wanted a baseline to quantify any gains/losses) you can remove the driver front NBo2 sensor and disable trimming from the factory o2 sensors in the calibration. Then install the WB in that exhaust bung, tune the MAF and VE to your satisfaction, then remove the WB and reinstall the factory sensor and re-enable trimming. It involves a slightly modified calc_pids.text file than the original Calc.VET, but I have a thread with all the files you will need, along with how to disable trimming. Ill post it up in a sec.

[Wheelz]

Here is my thread

http://forum.efilive.com/showthread....271#post194271

[Wheelz]

And here is all the info to connect the LC1 to the V2

http://forum.efilive.com/showthread....1200#post81200

[joecar]

You could connect the LC-1 analog output 1 to drive the NBO2 signal to the PCM (so the PCM can run in CL)...

NBO2 plug:
- pin A (signal lo) = LC-1 white or green;
- pin B (signal high) = LC-1 yellow;


e.g. F-car plug shown yours may look different (cut off a plug from an old NBO2 or buy one):


I also provide power/ground to my LC-1 from pins D and C... this only works if your PCM does not switch NBO2 power on/off (i.e. pin C goes directly to ground and not to the ECM).

[icemanjc1]

LC-1 is on the way, but I have another question. Air per cyl oz/ cylinder vs. grams/cylinder. Why does the axis measured to cyl oz and not to grams per cylinder if we log in grams/cylinder? How are we supposed to track things like spark timing in the tune?

Also, the fuel that is sold around here is up to 10% ethanol. So being that my truck is calculating at anywhere from 19%-35% ethanol and adjusting accordingly, wouldn't it be wise to set B3671 higher to achieve a better AFR for the time being?