What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Geotrash]

Most O2 sensors are narrow band, they just basically tell the ecu if you're rich or lean (under or over 14.7).

A wideband O2 is more accurate and will tell you exactly what the air/fuel ratio is. When a car or engine is on a dyno they use one, and it allows the tuner to adjust the fuel and spark for best performance.

My mustang is supercharged and has a digital gauge on the steering column that uses a wideband O2 mounted in the exhaust system and tells me exactly what my a/F ratio is all the time. So when I'm at full throttle I can visually see if it's going lean and get out of it before anything bad happens. I like it around 12.1 to 12.3 and a wideband will be able that accurate. Sometimes it will be 11.8 or 11.9

An engine makes best power between 10.5 and 13 depending on the engine setup and whether it is naturally aspirated or boosted.

I did not know this, but it makes sense. Thanks for sharing.

Interesting side note: In piston-engined aircraft, we now track EGT and CHT on individual cylinders, and adjust the mixture to either very rich (100ºF+) or lean (50-100ºF) of peak EGT (average) to get our mixture set just right for climb, cruise or descent. People operated aircraft for decades about 50ºF rich-of-peak EGT to supposedly keep the exhaust valves cooler. Cylinders would last maybe 800 hours. It became just SOP to plan on replacing cylinders at least once during an engine's TBO run. Then along came some engineers in Tulsa who figured out how to put pressure transducers inside of each cylinder to record internal cylinder pressures. They discovered that peak internal cylinder pressures happened at about 50ºF rich of peak EGT - right where everyone had been taught to run them. And, that meant it was also where there was the highest chance of pre-ignition, and where combustion events generated the most heat as a result, which of course went right into the material of the cylinders making them harder to cool effectively.

Long story short, switching to running the engines on the lean side of peak EGT, which everyone was afraid to do due to decades of 'conventional wisdom', makes the cylinders last more than twice as long, with lower fuel burn. Go figure. Funny thing about it though, they looked back at the old Pratt & Whitney operating manuals from the WWII era and found that lean-of-peak is the way they recommended their piston engines be run way back then. Somehow, an entire industry had gotten it wrong for decades between WWII and around 2005.

 

[alpha_omega]

So…repost from a few days ago.

Anyone changed out their rear output shaft seal? Did you do a Yoke and DS swap as well?

 

[gunninks]

What do you think of it so far?

I have been looking at getting something like this, mostly because i carry and having it bolted down feels a little more secure should i need to leave it in the car for a bit.


I'm also a lock nerd, usually things like this have a retarded/simple lock installed.
Retarded like a child with a paperclip, youtube, and a.d.d. meds could make short work of.

My current little cable lockboxes are stupid like this.
Good enough to prevent a smash and grab tho.

Over all I like it. I also am a lock nerd but also understand that locks only keep the honest, honest. That being said, I still want to keep my side arm secure when needed which is why I got this box. Its a double bitted 10 tumbler lock that would probably be a difficult for an armature lock picker. The box it self is not fully encased by its self but uses the sides and the bottom of the inside of console and then screws into the 4 factory holes at the bottom. The top of the box is stopped from being pulled up by the inside top of the console and fits very snug so it wiil not be that easy for someone to simply rip out in a short amount of time. There is also enough room between the top of the safe and the console lid to store small items. https://tuffyproducts.com/products/...yukon-xl-note-w-flow-thru-console/?sku=360-01

 

[Trey Hardy]

Swapped out the rough country UCA for some fabtech uniballs and dirt king cam locks

 

[Tonyrodz]

Mine was black. I wanted to buy a Cyclone back then but opted for an 87’ Grand National Twin Turbo instead. Much better investment…

I traded the Ty for an 87 also
Bought it with 44k on it back in 95, gave it to my son with 48k on it last summer.

 

[avalonandl]

I changed the oil, oil filter and air filter today. This was my first oil change since installing the catch can. After 5k miles, it hasn't caught a lot. But I'm glad what it did catch didn't end up in the intake.

View attachment 345494

That is not enough to worry about.

 

[Kee Fuller]

I have regular leather seats that aren’t old, but I’m Debating on redoing my front seats to perforated leather to add cooled seats. Or should i get some used ppv seats and redo those seats and sell my current seats? Decisions decisions.

 

[Bill 1960]

I did not know this, but it makes sense. Thanks for sharing.

Interesting side note: In piston-engined aircraft, we now track EGT and CHT on individual cylinders, and adjust the mixture to either very rich (100ºF+) or lean (50-100ºF) of peak EGT (average) to get our mixture set just right for climb, cruise or descent. People operated aircraft for decades about 50ºF rich-of-peak EGT to supposedly keep the exhaust valves cooler. Cylinders would last maybe 800 hours. It became just SOP to plan on replacing cylinders at least once during an engine's TBO run. Then along came some engineers in Tulsa who figured out how to put pressure transducers inside of each cylinder to record internal cylinder pressures. They discovered that peak internal cylinder pressures happened at about 50ºF rich of peak EGT - right where everyone had been taught to run them. And, that meant it was also where there was the highest chance of pre-ignition, and where combustion events generated the most heat as a result, which of course went right into the material of the cylinders making them harder to cool effectively.

Long story short, switching to running the engines on the lean side of peak EGT, which everyone was afraid to do due to decades of 'conventional wisdom', makes the cylinders last more than twice as long, with lower fuel burn. Go figure. Funny thing about it though, they looked back at the old Pratt & Whitney operating manuals from the WWII era and found that lean-of-peak is the way they recommended their piston engines be run way back then. Somehow, an entire industry had gotten it wrong for decades between WWII and around 2005.

That’s really interesting, and makes me go hmmmm…

Is it a coincidence that right about the time the EPA forced automakers to get lean typical engine life more or less doubled? Carbureted days 100k was a tired old engine. That’s nothing today.

 

[Bill 1960]

I have regular leather seats that aren’t old, but I’m Debating on redoing my front seats to perforated leather to add cooled seats. Or should i get some used ppv seats and redo those seats and sell my current seats? Decisions decisions.

In Vegas? Cooled all the way. My vinyl seats are one thing I’ll end up changing. My shirt back gets soaked in hot weather because the seat doesn’t breath.

If you buy seats watch out for compatibility of the passenger presence sensor. That was a big headache on mine because someone swapped in the wrong seat. Not all the GMT900’s use the same sensor.

 

[Kee Fuller]

In Vegas? Cooled all the way. My vinyl seats are one thing I’ll end up changing. My shirt back gets soaked in hot weather because the seat doesn’t breath.

If you buy seats watch out for compatibility of the passenger presence sensor. That was a big headache on mine because someone swapped in the wrong seat. Not all the GMT900’s use the same sensor.

I would pull the seats from a PPV or the seats that look like mine from the side.