How to begin tuning a 2003 4.8 engine

[chevyman08]

Well I have a 2003 4.8 and I dont even know where to begin tuning it. Can someone please give me some advice on which areas to tune to gain some noticeable HP

[joecar]

ChevyMan08,

Welcome to the forum.

Read these documents:
- scantool user manual pdf,
- tunetool user manual pdf,
- AutoVE Tutorial pdf.

Then take as many logs as you can and analyse those logs to determine how your motor is running... in order to make changes you have to unsderstand how it's running.

In the tunetool, take a look at the following tables:
B0101
B3605
B3618 and the tables that enable this
B4001
B5001
B5913
B5914

The idea is this:
get your VE and MAF tables corrected such that the actual AFR equals the commanded AFR...
then when this is true, you just set the AFR in B3605/B3618 for the best HP/TQ...
the best AFR for HP and/or TQ is publically published empirical data.

You will need a wideband O2 sensor (measures the actual AFR).

That would keep you busy... ;)

Cheers,
Joe
:cheers:

[chevyman08]

How do I know how much to modify different areas?