Keithstir

That I know of since I've owned it right about 1 year now

Truetrac diff rear last month
Yukon ring & pinion 4.56s, last month
18" Mickey bajas 35s
Standard 4l60 tranny

The mod inline with the IAT sensor I felt was necessary until I can score Diablo tuner after Christmas. The ECM runs this truck waaay too lean on it's own. Throws no codes either unless your 80% throttle or higher.

FFDP

iTrader: (2)

Not to argue, but a stock calibration is extremely rich from the factory. They call for nearly 10.9 AFR the longer you stay in the throttle.

Keithstir

I'm not disagreeing with you but unless I use the mod on the IAT It runs like gramps Sunday V8 chevy. Turn that fuel up and the truck is wild.

Keithstir

Another interesting thing is the truck surges in speed density mode. Half throttle or less it feels like you turned the ignition off then on again in less than 1 second. Random event that only happens when I unplug the maf.

I may not find exact answers to everything right off but I learn with people's replies. I enjoy new information about my Vortec

Mods89

Post a video of the idle. The little IAT thing that tricks the PCM does nothing for performance. If anything, it will make less power with the added fuel. Now, if the pcm was tuned to add timing a that temp, then you could see a gain. Like other people are saying, if you are beating stock diesels, thats normal. When my friends 6.4 powerstroke was stock, it got beat by a saturn vue... My guess is your stock with maybe a tune, the gears are helping you. Have you gotten a tune to correct your speedo with the gears and tire size?

Keithstir

I agree with you on the IAT mod for a factory motor, it would do nothing besides probably be slower and just use more gas. The truck is at operating temp in the video btw.
The truck does performance wise what I mentioned earlier with the old 3.73 gears.
Used to I would always have to run everyone down and pass them in midway through 2nd. With the 4.56s it jumps out in front and stays there from the takeoff.
No I have not tuned it. It cuts the fuel off at 85MPH now :/
Unemployment has played its hand on me this year so I am way behind on the basics.

01WS6/tamu

iTrader: (36)

Flash it back to factory go take the truck to a tuner who knows what they are doing and get a full custom tune. Remove all the snake oil aftermarket garbage you have put it on IAT altering devices MAF's ETC all of it. Diablos are not for modded vehicles pull the IAT mod that's crap also. Put the stock MAF and quit screwing with it. The truck is not lean no way no how not happening lean is not your problem.

There are all kinds of turbo and supercharged guys here running stock hardware on 1000+ hp trucks stock is best in all circumstances

A tune by a pro will fix all of your problems. Every problem you talk about is tune related.

Keithstir

If it is stock then I am ok with that.
I've drove chevy V8s for years. I had old school 350, vortec 350 LS1 crate motor, LM7 in my 04 avalanche and this 09 LY5. My first vehicle was a blue valve cover Olds rocket 350 from a 78 delta 88 in a coupe 84 cutlass.
My point is I'm not expert but I'm not a novice either. I appreciate everyone's knowledge!
My avalanche had exhaust from CAT back, full K&N intake setup, same tranny and 3.73 gears.
My current 09 LY5 Rado, same tranny, 3.73s (before the 4.56s) was smashing that avalanche by far more than a 20HP difference between a Gen3 and Gen4 Vortec.
If its not the cam it may have had head work done.


01WS6,


I appreciate your information but I cannot remove the mod on the IAT as the power gains are too much to let go of. Ive tried 3 different mafs, all OEM replacements bro. Its an OEM MAF on it now.
The diablos are not meant for modded engines, check.
I also agree on the stock hardware and that's all Ive tried.
My question to you is,
If lean is not the issue, how come a 0 degree day reading from the IAT is like night and day on this engine?
It's tripping me out on the fuel it takes and creates power. The more fuel I dump in, the faster it gets.

FFDP

iTrader: (2)

Install a wideband, then you'll figure out that you arent adding any extra fuel.

Cooler, more dense air makes more power anyway.

Keithstir

That's one I will for sure add later on. I agree but the air is not cooler, the ECM just thinks it is and adds fuel to compensate.


At idle, I turn up the resistance on the IAT via the volume ****, get out, walk to the back and smell straight fuel. I go back, turn the resistance back down to nothing, check exhaust again and it smells like nothing. The mod does work