2012 LTZ falls on its face...

[ILSMKU]

I have a 2012 LTZ with a volant CAI and 24" Lexlani DX9 Rims. I dont drive it much (its the wife's), but when I do, I feel like it falls FLAT on its face every time I get it some gas to get going! It will nose dive then immediately HIGH REV and finally get going. Im also getting a lifetime average of 12.5MPG! And this is wife driven 99.9% of the time (slow).

Im here to ask if its normal for the Tahoe to fall on its face whenever you peg the throttle? IF NOT, could it be the Volant CAI (who I had never heard of, but purchased from the truck shop that did my electric running boards)?


Or is this the 4 cylinder to 8 cylinder mode change over that causes the tahoe to fall on its face?

And does anyone else experience the funky shifting points on the highway? Say Im cruizing 75MPH and want to get it up to 80MPH. For some reason, giving it some more throttle doesnt do MUCH at all. But once I give it just a little bit more, it downshifts and HIGH REVS to much. Its like it wants 100% full throttle or NONE at all to accelerate.

Any suggestions?

 

[THE YETI]

Blackbear tune.

 

[ILSMKU]

Blackbear tune.

Are you saying that what I'm experiencing is normal? Could my CAI or big wheels be the cause of this?


And will the tune void my engine warranty? I understand the mag/moss act, but at the same time its easy for a dealer to say, "the tune made more power and put more stress on the engine and drive trian than it was designed for" and its a uphill battle for me to get any warranty items fixed if they know I have it.

 

[JennaBear]

Intake needs to be tuned for. You are probably confusing the PCM with the different airflow. Larger wheels/tires need to be taken into account as well.

 

[ILSMKU]

Intake needs to be tuned for. You are probably confusing the PCM with the different airflow. Larger wheels/tires need to be taken into account as well.

Hi Jenna,

So let me get this straight... am I doing more harm than good running that CAI WITHOUT a tune?

And do 24" wheels need to be programmed to the truck for it to shift properly or something?

Finally, if I was to get a tune, can the dealer tell I have one next time I take it in for service?


Thank you!

 

[JennaBear]

Yes, CAIs need to have a tune to actually give you any benefits. All our customers with Volants have had airflow problems, and were in desperate need of a tune (usually they would see a CEL). Your shift points should be changed for the 24s, especially if your speedo has not been calibrated for them; your MPH/RPMs are almost certainly off.

Since you have a 2012, you would need an AutoCal. As long as you return your tune to stock for dealer visits, you are good to go. With the current methods, the dealer can not detect tuning, so long as it is returned to stock (which you can do with the AutoCal).

 

[Zed 71]

And does anyone else experience the funky shifting points on the highway? Say Im cruizing 75MPH and want to get it up to 80MPH. For some reason, giving it some more throttle doesnt do MUCH at all. But once I give it just a little bit more, it downshifts and HIGH REVS to much. Its like it wants 100% full throttle or NONE at all to accelerate.

Any suggestions?

The 6-speed tranny is funky itself. Assuming you have bigger diameter tires/wheels the odo is off adding to the apparent loss in mpgs. Blackbear will take care of it ...

 

[ILSMKU]

The 6-speed tranny is funky itself. Assuming you have bigger diameter tires/wheels the odo is off adding to the apparent loss in mpgs. Blackbear will take care of it ...

Cool, thanks. I thought I think I had the dealer program the new tires, but I could be wrong.

What are you guys seeing for MPG for city?

 

[JennaBear]

What octane are you running?

 

[THE YETI]

There is a programming update called a VCI (or VIC). If you alter the wheels on a late production 2012+ vehicle, it will effect the way the vehicle shifts. GM has a download that would need to be done and I believe they charge about $45-60 for this.

That is problem #1. Problem #2 is you really should tune that vehicle to get it to run optimally, as indicated by JennaBear. I just said get a Blackbear Tune because that is what I, and 90% of the GM world, use to make their vehicles run like they should.