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

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j91z28d1

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I don't think opening up the exhaust will do anything but make it sound different.
gearing might help like 3.73 4.10
@swathdiver


yeah probably not.. I was watching the throttle body % while driving and over about 50% it would up the ratio and rpm. these trucks have a weird 4 gears then what they call variable gear ratio but they get it with clutch disks somehow not cvt band. weird, but anyways my thoughts was if I could build more tq under 50% opening it could pull harder before it upped the rpm.

maybe a good cold air intake with a little ram effect and mine has a spring loaded exhaust valve plus an extra resonator. so basically you can't hardly tell if the engine is running or not. which I do like daily, I think to stopping and starting non stop while diving with an loud exhaust would be very annoying. but for the tow trips I was thinking of wiring the spring loaded flap open. and could even v band the extra res if I could make any noticeable difference.
 

Doubeleive

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yeah probably not.. I was watching the throttle body % while driving and over about 50% it would up the ratio and rpm. these trucks have a weird 4 gears then what they call variable gear ratio but they get it with clutch disks somehow not cvt band. weird, but anyways my thoughts was if I could build more tq under 50% opening it could pull harder before it upped the rpm.

maybe a good cold air intake with a little ram effect and mine has a spring loaded exhaust valve plus an extra resonator. so basically you can't hardly tell if the engine is running or not. which I do like daily, I think to stopping and starting non stop while diving with an loud exhaust would be very annoying. but for the tow trips I was thinking of wiring the spring loaded flap open. and could even v band the extra res if I could make any noticeable difference.
Pretty sure the best bang for the buck for towing is going to be changing the ring & pinion, more power at take off and higher towing capacity, rpm's will be slightly higher at cruising speed
 

belair62

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I just grew up with fireworks always had firecrackers because you can get tons of them for cheap, neighbor across the street had a real cannon he was a pretty cool old dude with acres of old cars all over his property and he could care less if we explored all over, he would fire that cannon off and man that was fun times.
nobody complained, was def a different time period
I live in Illinois. I think friggin matches are illegal. I have a cabin in Wisconsin and I got here for my fireworks. I have to sign a permit for the mortars and big stuff. I buy the biggest mortars available. Not sure exactly what class they are but a step u der professional show type stuff. I cant use them in Illinois because people will shit themselves.

EDIT...to clarify...Chicago area...where people are ******* and not normal.
 

swathdiver

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these trucks have a weird 4 gears then what they call variable gear ratio but they get it with clutch disks somehow not cvt band.
What truck?

3.42 gears with 5.3s is fine for most towing but for towing heavy and up steep grades, deeper gears of course will help.

If I quit procrastinating, I'll put 3.73s in mine like some others have done on here. This lets the drivetrain do more work with less load on the engine even though she'll be turning more rpms.

I'm indecisive because I have two 6.2 pickups and my wife wants a 5th wheel to travel across country with so if we go that route, then a Duramax is in my future and I would not NEED the 3.73s in the Yukon.
 

alpha_omega

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I'm indecisive because I have two 6.2 pickups and my wife wants a 5th wheel to travel across country with so if we go that route, then a Duramax is in my future and I would not NEED the 3.73s in the Yukon.
I’m in the same boat. Do I let the wife pick out a Denali Duramax for hauling horse trailers, or pay a hauling fee? Either option will determine which gears I may eventually put in my Yukon.
 

swathdiver

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I’m in the same boat. Do I let the wife pick out a Denali Duramax for hauling horse trailers, or pay a hauling fee? Either option will determine which gears I may eventually put in my Yukon.
Decisions, decisions!

In our case, we already have the gears for the rear axle and everything to overhaul it, just have to do it and then figure I'd pick up a junkyard front differential with 3.73s and stick it in and overhaul the original at my leisure. PLus, we're taking the truck out west later this year. Do I make the trip with 3.42s or 3.73s? LOL
 

Geotrash

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What truck?

3.42 gears with 5.3s is fine for most towing but for towing heavy and up steep grades, deeper gears of course will help.

If I quit procrastinating, I'll put 3.73s in mine like some others have done on here. This lets the drivetrain do more work with less load on the engine even though she'll be turning more rpms.

I'm indecisive because I have two 6.2 pickups and my wife wants a 5th wheel to travel across country with so if we go that route, then a Duramax is in my future and I would not NEED the 3.73s in the Yukon.
For what it's worth, we've run into a handful of other campers now who told us they worked their way up to a 5th wheel and then decided it was too much and went back to a smaller bumper pull. They cited costs, maneuverability and overhead clearance in places like gas stations, difficulty finding campsites big enough, and some found that they just didn't need or want the extra space like they thought they would.
 

j91z28d1

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What truck?

3.42 gears with 5.3s is fine for most towing but for towing heavy and up steep grades, deeper gears of course will help.

If I quit procrastinating, I'll put 3.73s in mine like some others have done on here. This lets the drivetrain do more work with less load on the engine even though she'll be turning more rpms.

I'm indecisive because I have two 6.2 pickups and my wife wants a 5th wheel to travel across country with so if we go that route, then a Duramax is in my future and I would not NEED the 3.73s in the Yukon.


yeah see. mines the 6.0 hybrid with the 2ml70 tranny. it's so different then anything I've have modded before. makes it interesting to me and I only tow maybe twice a year and not a big rv but I would like to upgrade to enclosed car trailer at some point.


these have 3.08 gears in my year but back earlier the caddy had 3.42 gears. but they all switched to the common 3.08 about 2010. no tow rating change, still the small diff size and over all better mileage.

the high gear is 4th and I've have to double check but I believe it's a 0.74 ratio. which if I want the higher rpm of a 3.73 I could just tow in M4. there's no actual overdrive or lock up in a converter. just the veriable ratio of 1.7 or something like that, if I remember right can bring that 0.74 down to a 0.50 to keep rpm down. I've read how this works like 5 times and still can't fully wrap my head around it. it uses planetaries and the speed of one the internal electric motor to change the ratio to almost anything of that planetarie. it's kinda a cvt that doesn't wear out that is constantly changing to bridge gaps between the 4 main gears and produce over drive too.

but when on the interstate it basically trys to keep the rpms the lowest for mileage. on flat ground it would roll along at 0.50 ratio (it shows the ratio in the scanner) but as you go up and down it looked like once it opened the TB to 50% even if you don't move the throttle pedal much, it raises the ratio and the rpms go up. while watching mpg fall. so after a few hours of watching this it got me wondering if i could add hp to the engine at less throttle opening if it would say in (high gear) longer getting better mileage.

so like these are the modes.

1280px-Two-Mode_Hybrid_Transmission_Schematic.svg.png

1200px-6953409graph.svg.png

and this is what you get ratio vs speed.
TwoModeHybridTransmissionExample_04.png


as someone that's never liked automatic trannys. this one scares the hell out of me plus is also very interesting.
 

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