Hey guys. Hopefully you can help me out and understand the frustration I am going through. I have a 2011 turbo 5.3 gmc that is giving me hell. Like most of us here, I am a do it yourselfer,plus I am a perfectionist when it comes to my own personal projects. I want it done right and the way I want it. Unfortunately it seems most shops don't operate that way, go figure. Anyways, I current have HP tuners pro and I am attending a tuning course (wont mention any names). Over that past couple months I have spent countless $$ on gas driving around and getting my vve and MAF dialed in, or so I thought. It seems though that once I get the fuel trims dialed in they seem to get worse as time goes on. That's one of my frustrations. My main frustration right now though is that I am trying to get my MAF dialed in at the higher htz but I am getting TONS of knock retard. Matter of fact, it's pulling more timing than I have in it 😧. Right now I have it set to a conservative 9 degrees at wot on 93 and 13.5lbs of boost. It's a 5.3 with CNC 799 milled heads that I did as a project, trick turbo stage 3. Compression ratio is around 10.3:1. It's a e38 PCM running a blended vve/MAF. The MAF takes over at 2750rpm. I tuned the vve up to 3500rpm and 100 or so kpa. I want to say it's false knock but I just hate the idea of having to desensitize the knock sensors. I am wondering if maybe something isn't right on the heads or something else. Basically I am just frustrated with having this sweet ride and not being able to go out and beat the crap out of it.

 

You have a scan we could look at? Torque management disabled? Where are you IAT's at and where is your sensor mounted?

 

Since you're in Houston, I HIGHLY recommend you talk to PatG down in Victoria about tuning your truck. He can do everything you're trying to do on the street on his dyno and tune will be spot on. I've taken my personal truck to him as well as several other trucks and by far the most comprehensive tuner I've even been to. He's not just a WOT tuner like most, he tunes all aspects of drivability.

 

Yes I can get one. I can promise you though that the iats are good. We had a cold front come through and it was seeing KR with 52 degrees IATS UNDER BOOST lol.

 

Yeah, I've heard nothing but good things about him. Hell, I've even emailed him before about getting it tuned by him. Unfortunately I am very hard headed and want to do things myself but hey, that's how you learn right? This post was more or a rant as I posted it when I was pretty upset haha. My fuel trims at part throttle and such seem pretty good as of now. I figured it was my evap throwing my LTFT off. I really just need to figure out the KR issue and the safest way to go about desensitizing the sensors so that they can only pick up real knock. On a side not, I really want your t-6 twin scoll hot side kit with the borg warner turbo you designed it off of. Super nice! My genius self decided to go with a different turbo that you didn't offer with the kit and I had big issues with the downpipe hitting the frame and the crossover. So my downpipe has a nice dent in it. I should have just got the turbo that you designed the kit off of

 

You need to first figure out if it's real or not. Too little timing can also cause pre-ignition and knock.

You didn't mention any meth or e85 so I will assume it's pump gas, in which case, 13.5psi sounds about right for when you start having issues on pump gas only. Especially at your high compression ratio regardless of what the internet warriors say.

You didn't say what plug but you need a 7 range in there.

There is more to tuning than just looking at the laptop.

 

Most people and tuners forget to disable burst knock. At 9 degrees I wouldn't expect any real knock on 93.

Post your tune and logs. We can definitely help.

 

PatrickG did a few jobs us. Zero issues.
Would like to have a local or even in house tuner.

 

Cool, well if you decide to get some help, Pat holds nothing back and will teach you and share just what he is doing to your truck as he tunes it so might be worth the education. He's not one of those "I'm a Magician and can't reveal my secrets" tuners, lol

 

It is on 93 only right now while I am working on the tune but I normally run e85. It still pulls timing with e85 as well. I'm Running Br7ef plugs