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

[Sparksalot]

Tried to do a 0-60 with all nannies off. Forgot I was in 2WD. Did a burnout by accident all the way down the damn street.

You say that like it’s a bad thing.

 

[1BADI5]

Dyno appointment today.

Finally getting the WOT tables and E85 dialed in. Been waiting for this since before Christmas, but work has been crazy.

Got on the dyno and everything that was looking great until we hit 5000rpm.

Long story short, we have concluded that its valve float. So I either have a broken valve spring or the heads I bought did not come with the .660 springs as advertised. We did 6 runs and the graph was the same and breaking up in the same spot everytime at 5K rpm.

The good news, he had a set of BTR springs with all the Ti hardware in stock, so I grabbed them. Secondly, the torque curve from 1700 up to 5K was ****.

So I will take a sickday this week when its 70* and enjoy to task of swapping the springs and hardware.

 

[gooffeyguy]

Got on the dyno and everything that was looking great until we hit 5000rpm.

Long story short, we have concluded that its valve float. So I either have a broken valve spring or the heads I bought did not come with the .660 springs as advertised. We did 6 runs and the graph was the same and breaking up in the same spot everytime at 5K rpm.

The good news, he had a set of BTR springs with all the Ti hardware in stock, so I grabbed them. Secondly, the torque curve from 1700 up to 5K was ****.

So I will take a sickday this week when its 70* and enjoy to task of swapping the springs and hardware.

You sure it's valve float and not spark blowout?

What were the numbers up to that point?

Sent from my SM-G930V using Tapatalk

 

[iamdub]

What’s wrong with a full tank of gas?

It's sits so much and gasoline loses its potency over time. Keeping enough in there to get me around as needed ensures that I'm getting the freshest gas possible.

Plus, its only half the weight of a full tank, because racetruck.

Aaaand, I'll be replacing the pump sometime when the weather and my schedule calms down. I won't have much of a notice, so not having a full tank as a factor is a huge help.

 

[wjburken]

It's sits so much and gasoline loses its potency over time. Keeping enough in there to get me around as needed ensures that I'm getting fresh gas as needed.

Plus, its only half the weight of a full tank, because racetruck.

Man, I can’t even imagine having a vehicle that sits long enough to worry about the gas losing ummph. If I can get a week out of a tank, I’m feeling pretty good.

 

[Rocket Man]

Man, I can’t even imagine having a vehicle that sits long enough to worry about the gas losing ummph. If I can get a week out of a tank, I’m feeling pretty good.

Yeah I don’t even drive much anymore since I semi-retired and I can still run through gas fast enough. Of course it would help if I didn’t drive it like a race truck every single time...my last tank was 8mpg but part of that was in snow.

 

[iamdub]

Man, I can’t even imagine having a vehicle that sits long enough to worry about the gas losing ummph. If I can get a week out of a tank, I’m feeling pretty good.

Yeah I don’t even drive much anymore since I semi-retired and I can still run through gas fast enough. Of course it would help if I didn’t drive it like a race truck every single time...my last tank was 8mpg but part of that was in snow.

If it weren't for me finding reasons to drive it, it'd sit for 3-4 weeks between drives. I was glad yesterday when Kin asked me to take her to her friend's house. That meant a solid six miles driven (round trip) and the gas station was nearby.

 

[iamdub]

If it weren't for me finding reasons to drive it, it'd sit for 3-4 weeks between drives. I was glad yesterday when Kin asked me to take her to her friend's house. That meant a solid six miles driven (round trip) and the gas station was nearby.

I just realized something: In 11 hours, it would be exactly one year from when I took it to the track for the baseline runs. I crossed 200,000 miles that night on the first pass, made a few more, went to dinner then took it home to begin the teardown. I'm currently around 4,400 miles since then. 1,900 miles of that is the Thanksgiving trip to Tampa.

 

[wjburken]

I just realized something: In 11 hours, it would be exactly one year from when I took it to the track for the baseline runs. I crossed 200,000 miles that night on the first pass, made a few more, went to dinner then took it home to begin the teardown. I'm currently around 4,400 miles since then. 1,900 miles of that is the Thanksgiving trip to Tampa.

Our Yukon we bought with 89K in July of 2019. It has 115K now. That’s 26K in less than 2 years. My truck I bought 4 years ago last week with 17.5K. It now has 88K. 70.5K in 4 years. This is why I will never have low mileage vehicles.

 

[Sparksalot]

Got on the dyno and everything that was looking great until we hit 5000rpm.

Long story short, we have concluded that its valve float. So I either have a broken valve spring or the heads I bought did not come with the .660 springs as advertised. We did 6 runs and the graph was the same and breaking up in the same spot everytime at 5K rpm.

The good news, he had a set of BTR springs with all the Ti hardware in stock, so I grabbed them. Secondly, the torque curve from 1700 up to 5K was ****.

So I will take a sickday this week when its 70* and enjoy to task of swapping the springs and hardware.

Are you going to change them with the heads still in place?