Black Bear Chicago Tune

[mikeyss]

'09+ got the 6l80
'07-'08 got the 4l60

Exceptions being the '07-'08 Escalade and Denali and the Tahoes that got the bigger engines (non 5.3l) got the 6l80.

He definitely has the 6 speed because he mentioned the tune causing 6th gear to be locked out below 45mph.

I would assume he would have the same gear ratio as you since your trucks are same year and engine/transmission.

I have 3.42 rear end, for now. I have been thinking of going to 3.73 in the future. When I keep it under 70mph is when I can see 20mph give or take a mpg. When its over 85, then its around 18 or so. Driving up Loveland Pass... 15mpg, but saw it go lower than that on the steep part.

 

[mikeyss]

Maybe I get better mileage out of my L9H because the Tahoe has a 2 speed transfer case, whereas the Denali is AWD.

 

[09 L9H]

Maybe I get better mileage out of my L9H because the Tahoe has a 2 speed transfer case, whereas the Denali is AWD.

My Tahoe has Autotrac 4WD so not sure what the difference is. Again, I find it crazy that your mileage is that good. Is your area pretty flat? I think I get about 15-16 cruising at 80, but my part of I85 is fairly hilly. Not attacking you or calling you a liar, I just want to figure out how I can get mileage as good as yours!

 

[mikeyss]

My Tahoe has Autotrac 4WD so not sure what the difference is. Again, I find it crazy that your mileage is that good. Is your area pretty flat? I think I get about 15-16 cruising at 80, but my part of I85 is fairly hilly. Not attacking you or calling you a liar, I just want to figure out how I can get mileage as good as yours!

A few things I can think of are, I removed the heavy ass 3rd row seat. That's gotta be 100lbs. I also think the tune has something to do with it too. It rarely downshifts out of 6th gear on the highway, the tune gives a slight horsepower and torque increase. Before the tune, some hills it would kick down a gear or 2. I have slightly larger tires, the sidewall is a 65 instead of 55 (my speedometer is recalibrated). Someone once told me, and I Do Not know if this is true, that since Colorado is high altitude (I'm at 5k feet) that the thin air takes horsepower away (true), but it allows the vehicle to pass through easier than air at sea level.

 

[09 L9H]

A few things I can think of are, I removed the heavy ass 3rd row seat. That's gotta be 100lbs. I also think the tune has something to do with it too. It rarely downshifts out of 6th gear on the highway, the tune gives a slight horsepower and torque increase. Before the tune, some hills it would kick down a gear or 2. I have slightly larger tires, the sidewall is a 65 instead of 55 (my speedometer is recalibrated). Someone once told me, and I Do Not know if this is true, that since Colorado is high altitude (I'm at 5k feet) that the thin air takes horsepower away (true), but it allows the vehicle to pass through easier than air at sea level.

Gotcha, this all makes sense. I'd take my third row out too but my apartment is too small to have anywhere to put it haha. And yeah, my truck does have to kick down a gear to get up hills at times, plus I run 33s. Regardless it's more load on the engine. Thinner air does mean less resistance, as fluid force is directly related to fluid density. One last question: how much did the tune and everything set you back? Might try to do an in-person tune if @BlackBearPerf comes to ATL in early 2019.

 

[BlackBearPerf]

Gotcha, this all makes sense. I'd take my third row out too but my apartment is too small to have anywhere to put it haha. And yeah, my truck does have to kick down a gear to get up hills at times, plus I run 33s. Regardless it's more load on the engine. Thinner air does mean less resistance, as fluid force is directly related to fluid density. One last question: how much did the tune and everything set you back? Might try to do an in-person tune if @BlackBearPerf comes to ATL in early 2019.

That's the plan, Atlanta, GA, Winter/Spring 2019!

 

[mikeyss]

Gotcha, this all makes sense. I'd take my third row out too but my apartment is too small to have anywhere to put it haha. And yeah, my truck does have to kick down a gear to get up hills at times, plus I run 33s. Regardless it's more load on the engine. Thinner air does mean less resistance, as fluid force is directly related to fluid density. One last question: how much did the tune and everything set you back? Might try to do an in-person tune if @BlackBearPerf comes to ATL in early 2019.

I paid $550 or something like that for the Autocal and their tune, plus they will do updates from there on for free. It's a worthwhile investment, especially if you have further mods planned.
They are good people, and I am planning to purchase ARH Longtube headers through them since they have been so good to me. Plus after installing them, they will be able to email me a updated tune to make the most power from them.

 

[mikeyss]

My Tahoe has Autotrac 4WD so not sure what the difference is.

Do you have 2HI, Auto, 4HI, and 4LO dial?

 

[cmc76]

I get the same squeal as Mikeyss. Slipping belt when I lay into it. Freaked me out the first time

 

[09 L9H]

Do you have 2HI, Auto, 4HI, and 4LO dial?

Yep, I just leave it in auto.