**DISCLAIMER - I am not responsible for you blowing up your engine. Take my results and advice with a grain of salt! This is not a definitive guide and is more me learning along the way and documenting my results. This document is updated as I go, please do not be upset that it isn't 100%
**NOTE - Please read the Help section of VCM Editor to understand how the ECM works. Some of the info is confusing due to flip flopped and incorrectly named stuff, but the basics are there and thanks to the HP Tuners staff for putting that together
**KUDOS to Chris from HPT, other tuners, and the EFILive folks for helping me understand what I'm doing.
This is a good link with comments from Chris that are helpful: http://www.hptuners.com/forum/showth...-Tuning/page11
The 1.4t Chevrolet Cruze is an economy car with an economy turbo, an economy engine, and an economy tune. Out of the box, the car is setup to run as lean as it can and make enough power to make the car mildly enjoyable.
Preparing The Tune -
The first thing that should be done is to prepare your tune to take added boost. To do this, I reduced the timing a little and fixed Power Enrichment settings to be richer and faster(disabling delay). I have attached a tune where you can see what I did with timing and Power Enrichment to an otherwise stock tune. It is always ideal to use a wideband too! Unfortunately, I do not have my wideband hooked up yet so I'm playing with fire, don't be dumb like me. On the flip side, people are buying mail order tunes left and right without this being an issue...
Adding Boost -
The first thing you can do is go out and do a run on the highway and somewhere safe away from other vehicles to see what your car is doing stock in terms of boost. For my tests, I get on the highway and do a 40 to 70mph WOT run which is perfectly legal.
With the stock tune, I am hitting and commanding around 12-13lbs of boost. I hit about .65 g/cyl here -
Now, I want to get more power out of this bad boy. Everything I have read says "Just up the torque limits!". Ok, I'll take this advice and record what happens.
Engine > Torque Management > General > Peak Torque & Brake Torque Limit
I added 100 to both of these to start with.
Next, I went out on the road again and logged. Check this out. Granted, it's not pure apples to apples, but the point is to illustrate how my desired boost and delivered boost have both gone up. Not pictured is how my airmass has now hit the 0 degree knock airmass limit of .70 g/cyl
That is an extra 3lbs of boost to get me to 16 just from upping the torque management.
Seeing that I was hitting a .70 g/cyl airmass, I figured maybe the Knock Airmass boost control limiter was limiting me, so I upped these limits for 0 knock, probably higher than I plan to make power-wise.
Engine > Torque Management > Turbocharger > Knock Airmass
I then logged with these changes. A little more desired boost, but not much.
Thinking back to the help file in VCM Editor and what some others have said, I figured now would be a good time to up the Driver Demand table to tell the computer I want to make more power.
Engine > Torque Management > Engine > Map A - Normal
Back to logging I go...
Sweet! More power! I also got some knock when hitting the throttle lightlywhile cruising, so I'll need to do something about that.