What did you do to your NBS GMT800 Tahoe/Yukon Today?

[Pressureangle]

Sounds like you might want to lean it out a little bit.

It's dead stock, there shall be no leaning lol

 

[Fless]

It's dead stock, there shall be no leaning lol

Get a scanner on it and read what the MAF is reporting at hot idle in g/s (not in lb/min).

Post up the long- and short-term fuel trims for both banks.

How long since the throttle body's been cleaned?

 

[tooleyondeck]

Just to follow-up from Saturday's post... details in build thread

 

[Pressureangle]

Get a scanner on it and read what the MAF is reporting at hot idle in g/s (not in lb/min).

Post up the long- and short-term fuel trims for both banks.

How long since the throttle body's been cleaned?

ECT steady at 181*

The throttle body gets cleaned at every oil change, coming due pretty soon.
It's never had new O2 sensors, either- dead dead stock. FWIW about 140k miles.

 

[S33k3r]

It's dead stock, there shall be no leaning lol

It sounds like you are getting a lower volume of air at hotter temperatures; I was suggesting reducing the amount of fuel delivered to compensate. Either that or you need a means of cooling the intake air.

I was not suggesting you had any kind of tune.

Sorry for being unclear.

 

[S33k3r]

Just to follow-up from Saturday's post... details in build thread

View attachment 465552

No offense intended! But I think the first set of wheels look the best. This is an unsolicited opinion and may be valued at the price you paid for it...

 

[S33k3r]

View attachment 465559

ECT steady at 181*

The throttle body gets cleaned at every oil change, coming due pretty soon.
It's never had new O2 sensors, either- dead dead stock. FWIW about 140k miles.

You know... Some sort of forced induction would likely improve your MPG -- if you kept your current driving habits. Just sayin'...

On a more reasonable note, if you were just trying to improve those MPGs, a low, low boost rate would be all that was required. You just want a consistent air charge.

NOTE: Raising MPGs is **NOT** all about saving money. It's also about increasing the distance between fill ups.

 

[Pressureangle]

You know... Some sort of forced induction would likely improve your MPG -- if you kept your current driving habits. Just sayin'...

On a more reasonable note, if you were just trying to improve those MPGs, a low, low boost rate would be all that was required. You just want a consistent air charge.

NOTE: Raising MPGs is **NOT** all about saving money. It's also about increasing the distance between fill ups.

I thought for a while before responding to this, for fear of sounding condescending or bristly.

Forced induction? Hard no. With the exception of small engines working in the top half of their capacity, boost will not improve fuel mileage. It improves power under load. Plus it's *extremely* expensive and a lot of work to fit up. Personally, I have little use for this giant of a motor anyway.
Distance between fills? I have 36 gallons on board, and even at 11mpg my need to test my aging bladder to save 15 minutes twice a day just doesn't compute anymore- it never really did had I done the arithmetic as a youth.
I'm not really concerned about upgrading the mpg, simply exploring a potentially simple and cheap improvement.

The elephant in the room wrt miles per gallon is as always, emissions. Our engines are constrained to how many oxides of nitrogen are allowed out the tailpipe, and that limitation equates directly to energy content allowed per gallon. I might be able to squeeze 10-15% out of this engine with a (again, expensive) pro tune, but without changing compression even that is limited. But as said, intake air temperature has proven to be a meaningful variable, and to a small extent that can be improved by keeping the underhood temps, intake manifold, and intake ports 10* cooler. We'll see with time.

 

[S33k3r]

I thought for a while before responding to this, for fear of sounding condescending or bristly.

Forced induction? Hard no. With the exception of small engines working in the top half of their capacity, boost will not improve fuel mileage. It improves power under load. Plus it's *extremely* expensive and a lot of work to fit up. Personally, I have little use for this giant of a motor anyway.
Distance between fills? I have 36 gallons on board, and even at 11mpg my need to test my aging bladder to save 15 minutes twice a day just doesn't compute anymore- it never really did had I done the arithmetic as a youth.
I'm not really concerned about upgrading the mpg, simply exploring a potentially simple and cheap improvement.

The elephant in the room wrt miles per gallon is as always, emissions. Our engines are constrained to how many oxides of nitrogen are allowed out the tailpipe, and that limitation equates directly to energy content allowed per gallon. I might be able to squeeze 10-15% out of this engine with a (again, expensive) pro tune, but without changing compression even that is limited. But as said, intake air temperature has proven to be a meaningful variable, and to a small extent that can be improved by keeping the underhood temps, intake manifold, and intake ports 10* cooler. We'll see with time.

FWIW, you do not sound condescending. I hyper focused on the ambient temperature killing your gas mileage. Then I assumed that hotter air was not as dense as colder air. So I suggested forced induction to maintain the same level of air density going into the engine. I *assumed* that more power = more fun, but I realize it is not for everyone.

I really don't know how to lower your intake air temperatures, short of alcohol or ice cooling -- definitely more expensive than stock, and super fiddly.

And, yeah, my bladder doesn't seem to hold as much as it used to, either.

 

[6speedblazer]

Drew this up and 3d printed one for each truck to get rid of the rear radios that no longer work.

Also smoke tested the evap system on my denali and found my P0455 "Large Leak" as the purge valve not sealing. Amazon got me an ACDelco replacement same day. so far so good on that one.

 

[latvius]

Drew this up and 3d printed one for each truck to get rid of the rear radios that no longer work.

Also smoke tested the evap system on my denali and found my P0455 "Large Leak" as the purge valve not sealing. Amazon got me an ACDelco replacement same day. so far so good on that one.

You planning on selling them or selling the design?

 

[6speedblazer]

You planning on selling them or selling the design?

Haven't really considered it, but it is a possibility. I would have to see what my costs would be to see if it's even feasible.

 

[latvius]

Haven't really considered it, but it is a possibility. I would have to see what my costs would be to see if it's even feasible.

Well if you're feeling philanthropic post it up on thingverse and give it away. Up to you just seems a waste to let your hard work designing it not benefit others whether you get money for it or good karma as compensation.

 

[tooleyondeck]

Haven't really considered it, but it is a possibility. I would have to see what my costs would be to see if it's even feasible.

I'd be interested in one if you make more.

 

[SilverSport]

6 quarts of Mobil 1 Truck & SUV, a Champ PH44XL oil filter and tires rotated...

Bill

 

[Fless]

Took it to have a brake fluid bleed and to have an axle seal leak fixed.

 

[tooleyondeck]

No offense intended! But I think the first set of wheels look the best. This is an unsolicited opinion and may be valued at the price you paid for it...

I like the street look more as well, but those wouldn't be my first (or 10th) choice of wheel. I went with 18s and A/Ts more for my wife who came from Jeeps until I enlightened her on the superiority of full-size V8 SUVs lol

 

[clandr1]

Earlier this week I ordered some socket organizers for the tool box. Pretty happy with them so far, but I am resisting the urge to buy all the missing sockets that I probably don’t need…

 

[latvius]

Earlier this week I ordered some socket organizers for the tool box. Pretty happy with them so far, but I am resisting the urge to buy all the missing sockets that I probably don’t need

But the sockets will cost almost as much as a new set, so you buy the set and then you have x2 sockets with nowhere to put them...ask me how I know

 

[tooleyondeck]

Earlier this week I ordered some socket organizers for the tool box. Pretty happy with them so far, but I am resisting the urge to buy all the missing sockets that I probably don’t need…

looks like you could use a 12pk of 10mm lol