06 LBZ low rpm boost leak

[freestylest22]

My 06 LBZ has a low rpm off idle boost leak. I'm running Idaho Rob tuning with a Danville Stage 2 GT3794 turbo. The truck will build 34psi boost up top but is a lazy turd off idle to 1500rpm. It will black smoke on the higher three tunes. Just normal slow driving I only carry 1-5psi boost. Anyone have an idea for my low pressure boost or where I should look first? Thanks in advance.

 

[kiwilml]

Sounds normal for my other truck, I've got an lbz and that's what it runs under light throttle.. I've got the same turbo on also..

If you can't hear anything leaking at 34 psi of boost than probably don't have anything at low boost?

 

[freestylest22]

Well Danville and Idaho Rob both tell me there's a boost leak. I hate a black smoking truck!!!

 

[quinton]

Isn't the same issue you had awhile back when you came by the house?

 

[IOWA LLY]

So check it for boost leaks....

It's pretty easy to make an adapter to hook shop air (regulated down) to the inlet of your turbo. Then just roll the engine over until it quits leaking through the engine out the exhaust, and start listening for a leak.

Sent from my SM-N920V using Tapatalk

 

[freestylest22]

Isn't the same issue you had awhile back when you came by the house?

Yes but more exaggerated now. Guess it's gotten worse over time or with the hotter tuning. Just had the trans built. I've done a boost leak but it held pressure. Going to try it again in the morning.

 

[quinton]

Yes but more exaggerated now. Guess it's gotten worse over time or with the hotter tuning. Just had the trans built. I've done a boost leak but it held pressure. Going to try it again in the morning.

I don't think there is anything wrong with it. It seemed normal to me. With a hotter tune it will be more smokey. You are adding more fuel to it.

 

[freestylest22]

The truck only carries 0-4psi of boost driving slow down the highway. Fuel milage sucks unless I run 80+ or pull it out of 6th gear. Running 70ish when I floor it, the truck falls on its face then finally spools to 34 or 35psi

 

[plowboy_lbz]

My twins only push 3-4 psi running 70. Boost takes fuel and more fuel = less mileage. I usually run in 5th gear unless I'm going 70+ otherwise
It's sluggish.

 

[IOWA LLY]

You could have them raise your desired boost up in the lower end of the tune. If you have checked it for leaks and found none then it's time to move on to something else.

Sent from my SM-N920V using Tapatalk

 

[IOWA LLY]

I have found that 3 to 5 pounds of boost will net good mileage. 6 to 7 seems to be OK as long as your rpms are 2000 or more. Less may gain a small amount of mileage but not enough in my experience to be worth the additional lag and smoke.

Sent from my SM-N920V using Tapatalk

 

[freestylest22]

No boost leaks. Lots of black smoke. Horrible running truck down low. Think I'll flash it back to stock. Probably will run better than the tuning I'm running now.