Chevrolet Suburban 3500 Questions

Bigburb3500 said:

Thanks for the tow review! Glad to know it can tow more than 3k lbs lol.

I cannot believe you found a truck with such low mileage. Absolutely insane, but the issue sounds like most cars that sit for long periods of time.

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I know. Finding one of these unicorns in the LT trim is hard enough, but finding a low mileage creampuff is another thing altogether. I just got really, really lucky.

With how these trucks are built, unless something else comes up in 10yrs that can match this truck I will probably start the mega upgrades. Not sure you saw the thread on here where someone dropped a new L8T into these trucks with a 6L90. We already have the 6L90 sooo would be pretty easy and a 10speed could also be used…

Bigburb3500 said:

With how these trucks are built, unless something else comes up in 10yrs that can match this truck I will probably start the mega upgrades. Not sure you saw the thread on here where someone dropped a new L8T into these trucks with a 6L90. We already have the 6L90 sooo would be pretty easy and a 10speed could also be used…

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Yup. I thought about that but I’m pretty happy with the power for my purposes - I have no problems keeping up with traffic while towing through the hills. If I make any engine changes in the next several years, it would likely be a cam since I have experience with that. I could see new wheels and tires in my nearer future, possibly a bull bar, and a class V hitch.

Part of the draw of this rig for me is how bulletproof the L96 is, so I’ll probably leave it alone - at least until I start having reliability concerns with it. One thing I will do for sure though is have a blackbear tune done since I already have their autocal device.

What else is on your wish list besides the L8T?

The L8T upgrade is a pipedream wish list. Right now the big items for upgrades are the shocks which I will order on Friday of this week, tow mirrors, and I also want new wheels. I love the BFG KO3s I put on when I bought the truck, and as much as I love the overall look of the suburban, my truck looks like a contractor special. It’s just plain white. Hoping to paint the black grill white to match + white tow mirrors and then throw a set of dark bronze 18” wheels on the truck. Few nice looking sets out there that would look good against the white.

what are your thoughts on blackbear tuning? Considering this truck does not have AFM or anything, what would the tune do?

Bigburb3500 said:

... thoughts on blackbear tuning?
Considering this truck does not have AFM or anything, what would the tune do?

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*It would net more power - not just over 5000RpM, but basically anywhere over 1500RpM, meaning that your MpGs may improve IFF you keep your foot out of it
*Your transmission has Normal and Tow / Haul shift maps available;
they can be more finely customized to suit your tastes AND improve durability / longevity at the same time
*(In your particular case the TCC behavior is likely superior to '1500' type vehicles;
generally when and how the TCC locks and unlocks improves MpG at the cost of longevity for '1500')
*There are engine coolant and ATF overheat mitigation protocols that GM tends to activate almost-too-late;
they can be adjusted to enable sooner for your benefit
(I've overheated ONE mid-90s LT1 engine myself, as a result,
all my LT1 tunes have GM's overheat mitigation protocols enabled sooner than GM OE, which has already saved two of them)
The tuners you consult will explain their menus better than I can, but the point is,
aftermarket tuning exists precisely because GM left them so much room for personalization and improvement.

Marky Dissod said:

*It would net more power - not just over 5000RpM, but basically anywhere over 1500RpM, meaning that your MpGs may improve IFF you keep your foot out of it
*Your transmission has Normal and Tow / Haul shift maps available;
they can be more finely customized to suit your tastes AND improve durability / longevity at the same time
*(In your particular case the TCC behavior is likely superior to '1500' type vehicles;
generally when and how the TCC locks and unlocks improves MpG at the cost of longevity for '1500')
*There are engine coolant and ATF overheat mitigation protocols that GM tends to activate almost-too-late;
they can be adjusted to enable sooner for your benefit
(I've overheated ONE mid-90s LT1 engine myself, as a result,
all my LT1 tunes have GM's overheat mitigation protocols enabled sooner than GM OE, which has already saved two of them)
The tuners you consult will explain their menus better than I can, but the point is,
aftermarket tuning exists precisely because GM left them so much room for personalization and improvement.

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Thanks Marky! This is super helpful and detailed. Probably will add this to my growing list. Why is this called a Yukon/Tahoe forum… it’s really a forum to open up our wallets…

Bigburb3500 said:

Thanks Marky! This is super helpful and detailed. Probably will add this to my growing list. Why is this called a Yukon/Tahoe forum… it’s really a forum to open up our wallets…

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Truth!

Another way to describe what a Blackbear tune does is that it 'wakes up' the vehicle. Throttle response improves, shift points are tuned for better drivability (the factory tune prioritizes economy), shifts are quicker with less TCC slip, and they can also tune for premium fuel if you wish, which increases power output a bit. In my case, one of the reasons I bought a truck with the L96 is because of the lower compression ratio that makes running 87 gas okay, so I'll ask them to focus on their usual suite of drivability and towing-related improvements, while making sure it will still be safe to run 87.

They tuned both of my Yukon XL Denali's and I've been thrilled with the results.

Geotrash said:

Another way to describe what a Blackbear tune does is that it 'wakes up' the vehicle.
*Throttle response improves -
*shift points are tuned for better drivability (the factory tune prioritizes economy),
*shifts are quicker with less TCC slip ...

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Other tuners besides BlackBear SHOULD be able to accomplish the above.
*Electronic-signal-throttle vehicles NEVER open or close the throttle as quickly as your foot can - unless you have your ecm tuned.
*GM OE transmission shift pattern not only prioritizes economy, it either encourages conservative driving, punishes enthusiastic driving, or both.
If you're a hypermiler, you might even ask your tuner to prioritize MpGs EVEN more.
The rest of us likely would want something less lazy than GM provides, though.
Since we have TWO shift tables, how do you want the 2nd one?
Since I'll likely NEVER tow anything, my Tow / Haul mode is more like a 'try as best you can to chase that TrailBlazer SS' mode,
which is why my normal mode prioritizes neither MpGs, nor lazy driving - it simply protects the 4L60E as best as possible.
Maybe you want your Tow / Haul mode to entirely avoid 6th, or 5th & 6th? You'll never get what you want if you don't ask.
*GM OE TCC behavior for '1500' type vehicles prioritizes NVH over durability/longevity.
Your 3500 may not have this particular problem, but most of us do ...

Marky Dissod said:

*GM OE TCC behavior for '1500' type vehicles prioritizes NVH over durability/longevity.
Your 3500 may not have this particular problem, but most of us do ...

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I suspect it does because there is lots of slip in the shifts. It's built to be armored and carry around dignitaries who would likely be quite cross if a harsh shift caused them to spill their Scotch while fleeing enraged proletariat.

Geotrash said:

I suspect it does because there is lots of slip in the shifts. It's built to be armored and carry around dignitaries who would likely be quite cross if a harsh shift caused them to spill their Scotch while fleeing enraged proletariat.

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hahahaha no further comment needed