2010 Cobalt (LNF) w/Knock after ZFR

[StruttinSoul]

Hi Guys,

My first time asking for some help on here! I've been an avid reader and learner but I now need some help.

The car:
2010 Cobalt SS
Turbo XS Upper Charge Pipe
ZZP Lower Charge Pipe
MAF Relocate (With ZZP Extension)
Tial Q 50mm BOV (With 8 psi spring)
Vacuum tank/solenoid bypasssed
ZFR 6758
ZZP Intercooler
GM Spark Plugs gapped to .027
MPx Catless Downpipe
ZZP Catback
K&N Intake
GMS1 MAP Sensors

I have been having nothing but issues with knock and it seems to be way too much to be considered false knock.
I was watching my RPD this morning and it would start with 10*-11* in second or first gear and then slowly ease down depending on how much pressure I put on the pedal but I could never really get it to 0.

My tuner has tried pulling a lot of timing but it has not helped and in some matters actually made it worse.


I think that's all the information that is really needed and I'll let the log file speak for itself. I can provide more at request.

Thanks!

[JimmyS]

You need to get your MAF dialed in for starters. Just a quick peek at your histograms shows that your MAF is out of whack. Get it to within +/- 1% and that will help. Until you get the MAF calibrated, I would turn the boost down a bit.

What type of fuel are you running?

[StruttinSoul]

I was originally running Chevron 94 but have since switch to Petro-Can 91.

I'm not personally tuning the car but I do know how to adjust the MAF tables based off of the log output so I'll start with the calibration table and try to bring the MAF tables in a bit.

[JimmyS]

Work the MAF until it is within 1% and then post another log.

[T-Man]

I'd like to know what your tuner is doing as far as spark/OS and cam tables. That log is ugly.... Post your tune if you feel comfortable but I can tell you right now, it looks as though you're running one of GMTech's or BYT's cam tables. Those are great tables IF everything else is working in perfect harmony and setup properly.

There's a lot of really nasty stuff going on in your log. Your fueling isn't great but it's not the sole reason as to why you're experiencing KR at low/mid loads. Not only that but you realize you're boosting 30psi? On 91 equivalent US gas?

My straight opinion? You're pushing the car way too hard on regular old pump gas. Between your cam tables and the amount of boost your "tuner" is commanding, it's just too much.

[StruttinSoul]

Thanks for the feedback guys!!

I did one mass MAF calibration change and knock is already a lot more in line - with the exception of cylinder 2.

Here's the log from my ride home.

As well as the tune - this is with my first MAF adjustment, about to make another one right now.

[JimmyS]

Good to hear. You might adjust your PE table a bit as it is rich in the lower rpm range and maybe just a tad lean on the higher rpm for 91 octane. Set your higher rpm range at .88 and see how it reacts. Smooth out your spark tables and make sure they are all the same. Do the same with your cam tables. On both intake and exhaust, the main warm, main cold and knock should be the same for base angle knock angle and catalyst heating since you have the catalyst heating disabled so start by copying your main warm table for intake into the other 4 and then do the same for exhaust.

Your tune has quite a bit of room for improvement but if you'll read up on the LNF bible that CSSOB posted you will start making some real positive progress. It has some good information to get you started but try to make adjustments to one table at a time and log the changes so you'll learn what's going on. Read and read and read and you'll get there. There are many good posts from GMTech, Codename Bil Doe, MikeM173, CSSOB and a few others that will help you out a lot so take the time to read as much as you can and you will find success. Ask questions as you make the changes and keep posting logs like you are doing.

[MikeM173]

Ummm... zero changes to cam tables except some mid range stuff, yet the Injector tables are completely changed up. Why is idle done up the way it is? PE table is no bueno and can cause issues. Timing tables... could be better. Optimum torque table... why? Still dialing in fuel but DFCO is still enabled? I love how people use the GM stage tables. The stock tune is horrible but we'll steal from the same tuners. Ouch wastegate tables! Why is your final drive ratio table changed!? No to your fuel system changes. Why do you have a ton of fuel pressure DTCs turned off along with other DTCs!?! I'm sorry but I started getting mad looking at your tune if you couldn't tell. It doesn't have room for improvement it has room to be completely changed. I don't have a 2010 stock file so forgive me if I'm wrong on something I pointed out, yet I don't think I am. Please tell me who tuned this in a PM.

[T-Man]

Injector tables and cam tables are slightly different for 2010 MY

[MikeM173]

I'm hoping most of what I see is due to the difference of the 2010.