6.6 Gas L8T Engine Swap in 2015 Suburban

[adventurenali92]

Sorry! It's been such a crazy couple of weeks. I dropped the ball and didn't think to buy new engine mounts until the 6.6 was already installed, DOH!!

Also have gotten upper/lower control arms, inner/outer tie Rods, shocks and struts on front and rear, serviced rear diff fluid. This thing should be like a new rig when I get it back.

I assure you guys that when it's back in my possession, I will provide ALL the good information. Including videos, many pics, and a complete pricing breakdown of it all. There will be no stone unturned, just bear with me guys!!

I've also got a plan in place to do what I'm calling an "rst conversion" of exterior mods. Trying to think one step at a time here, but it's tough!!

Dannngggg she’s gonna be brand new after that! That’s a ton of work! Well awesome!

 

[CMoore711]

Upgraded transmission to the 6l90 that can handle way more torque than the 6l80’s. Upgraded drive shaft.

You’re going to have a unique K2XX Suburban that’s set to provide you with many many miles!

 

[MTseat]

This is incredible. Thank you for documenting your swap. I also purchased one of the 6.6 off of eBay, and am planning on swapping into a 2015 Tahoe. Please keep posting your progress, and how the tuning went. Thank you!

 

[L8T BURB]

Update!!! I got a call from my technician today saying that he was "currently on the maiden voyage". He said the catalytic converters plugged up very qucikly into the first drive. Noting the notorious rotten eggs smell. He got it back to his shop and knocked the guts out of all 3 cats. The rest of the exhaust is still intact. Stock muffler, stock resonator, stock piping throughout. Note that the cats are still "technically" there, but there's nothing inside of them.

I got to hear it start a few times, and got to ride passenger in it! My tech didn't push it hard. About a 3 mile loop just to confirm the cats were cleared so he could continue to dial in the tune. The only downside I've seen so far is that there appears to be a light fuel odor when outside of the Suburban. Time will tell if that's due to the cats being gutted, or possibly a rich tune.

I have attempted to create a YouTube channel and uploaded the 2 short videos I captured today. It is scheduled to get an alignment at our local Chevy store in the morning due to all the steering and suspension parts that were replaced. All signs lead to me getting it back in my possession Friday! I promise PLENTY more videos to come that will be very descriptive and worth watching!

PLEASE PLEASE PLEASE give me a like, comment and subscribe! Channel is L8T_BURB

 

[Tonyrodz]

Update!!! I got a call from my technician today saying that he was "currently on the maiden voyage". He said the catalytic converters plugged up very qucikly into the first drive. Noting the notorious rotten eggs smell. He got it back to his shop and knocked the guts out of all 3 cats. The rest of the exhaust is still intact. Stock muffler, stock resonator, stock piping throughout. Note that the cats are still "technically" there, but there's nothing inside of them.

I got to hear it start a few times, and got to ride passenger in it! My tech didn't push it hard. About a 3 mile loop just to confirm the cats were cleared so he could continue to dial in the tune. The only downside I've seen so far is that there appears to be a light fuel odor when outside of the Suburban. Time will tell if that's due to the cats being gutted, or possibly a rich tune.

I have attempted to create a YouTube channel and uploaded the 2 short videos I captured today. It is scheduled to get an alignment at our local Chevy store in the morning due to all the steering and suspension parts that were replaced. All signs lead to me getting it back in my possession Friday! I promise PLENTY more videos to come that will be very descriptive and worth watching!

PLEASE PLEASE PLEASE give me a like, comment and subscribe! Channel is L8T_BURB

Wish I could give you 1,000,000 thumbs up! Sounds great. Your guy really figured it out. As for the cats--I'm also running cables on my 03. They're also deleted in my tune along with the downstream o2s. I also have the gas smell while it's running. Unfortunately I think it's unavoidable once the cats are gone. I wouldn't be surprised if you get an o2 cel.
Did your mechanic give her the "onions"? Lol, does she have some more noticeable power?

 

[L8T BURB]

Wish I could give you 1,000,000 thumbs up! Sounds great. Your guy really figured it out. As for the cats--I'm also running cables on my 03. They're also deleted in my tune along with the downstream o2s. I also have the gas smell while it's running. Unfortunately I think it's unavoidable once the cats are gone. I wouldn't be surprised if you get an o2 cel.
Did your mechanic give her the "onions"? Lol, does she have some more noticeable power?

My technician stated that he has "turned off the o2 sensors". My assumption is that this means I won't get any check engine light. All o2 sensors are still in place, just with gutted cats. The particulate or whatever it is that came out of the cats was wild looking! Chunks of white and gray stuff.

As for power, he didn't push it hard. On the short 3 mile loop, he got it up to 80 mph, but was a gradual acceleration. He noted he was pushing it to maybe 50% throttle, and it did feel VERY strong and was very smooth! Just from the passenger seat, it felt nearly as strong at "maybe 50% throttle" as my 5.3 felt under full acceleration. Of course I was just very giddy, so my opinion may vary once I get it back this weekend.

 

[Tonyrodz]

My technician stated that he has "turned off the o2 sensors". My assumption is that this means I won't get any check engine light. All o2 sensors are still in place, just with gutted cats. The particulate or whatever it is that came out of the cats was wild looking! Chunks of white and gray stuff.

As for power, he didn't push it hard. On the short 3 mile loop, he got it up to 80 mph, but was a gradual acceleration. He noted he was pushing it to maybe 50% throttle, and it did feel VERY strong and was very smooth! Just from the passenger seat, it felt nearly as strong at "maybe 50% throttle" as my 5.3 felt under full acceleration. Of course I was just very giddy, so my opinion may vary once I get it back this weekend.

That particulate that came out of the cats is what's so valuable--the reason cats are stolen. I also gutted one of my cats on my Express van due to it being clogged. It also has that gas smell while idling.

 

[L8T BURB]

That particulate that came out of the cats is what's so valuable--the reason cats are stolen. I also gutted one of my cats on my Express van due to it being clogged. It also has that gas smell while idling.

The gutted cats is a new thing for me. Never had a vehicle with them before. Do you ever smell that gas odor inside the cabin? Reason I ask is because I do have access to all 3 converters that came with the 6.6 engine that I could have welded onto the 5.3 downpipe. The reason we didn't use them in the first place was because the manifold angles were so different that the 6.6 manifolds wouldn't physically clear the firewall area. I'm not sure I'd be a fan of the gas smell inside the cabin of the Suburban.

Thoughts?

 

[Tonyrodz]

The gutted cats is a new thing for me. Never had a vehicle with them before. Do you ever smell that gas odor inside the cabin? Reason I ask is because I do have access to all 3 converters that came with the 6.6 engine that I could have welded onto the 5.3 downpipe. The reason we didn't use them in the first place was because the manifold angles were so different that the 6.6 manifolds wouldn't physically clear the firewall area. I'm not sure I'd be a fan of the gas smell inside the cabin of the Suburban.

Thoughts?

Hard to say about the smell coming inside. In my experience I've both smelled it coming inside, and other times I haven't noticed anything. Guess you'll need to feel it out. It's always easy enough for your guy to weld in the other cats if needed.

 

[adventurenali92]

Dang that’s rad sounding suburban right there! Heading to YouTube to hit follow cuz I wanna see every video you make about this thing! Definitely a unique K2 suburban you built yourself to roll around in!

 

[CMoore711]

The gutted cats is a new thing for me. Never had a vehicle with them before. Do you ever smell that gas odor inside the cabin? Reason I ask is because I do have access to all 3 converters that came with the 6.6 engine that I could have welded onto the 5.3 downpipe. The reason we didn't use them in the first place was because the manifold angles were so different that the 6.6 manifolds wouldn't physically clear the firewall area. I'm not sure I'd be a fan of the gas smell inside the cabin of the Suburban.

Thoughts?

I know the 5.3L K2XX SUV’s have 3” diameter factory cat-back exhaust pipe and 6.2L have 3.5” diameter factory cat-back exhaust pipe. Wonder what diameter cat-back exhaust pipe came on the 6.6L L8T HD trucks? If it’s 3.5” you may want to consider an exhaust upgrade?

Either way all that cutting and welding seems like a lot of work for factory exhaust manifolds and cats. To me it just sounds like a really good and justifiable reason to throw on some 1-7/8” long tube headers, a catted Y pipe, and an upgraded 3.5” cat-back exhaust.

 

[B-train]

Update!!! I got a call from my technician today saying that he was "currently on the maiden voyage". He said the catalytic converters plugged up very qucikly into the first drive. Noting the notorious rotten eggs smell. He got it back to his shop and knocked the guts out of all 3 cats. The rest of the exhaust is still intact. Stock muffler, stock resonator, stock piping throughout. Note that the cats are still "technically" there, but there's nothing inside of them.

I got to hear it start a few times, and got to ride passenger in it! My tech didn't push it hard. About a 3 mile loop just to confirm the cats were cleared so he could continue to dial in the tune. The only downside I've seen so far is that there appears to be a light fuel odor when outside of the Suburban. Time will tell if that's due to the cats being gutted, or possibly a rich tune.

I have attempted to create a YouTube channel and uploaded the 2 short videos I captured today. It is scheduled to get an alignment at our local Chevy store in the morning due to all the steering and suspension parts that were replaced. All signs lead to me getting it back in my possession Friday! I promise PLENTY more videos to come that will be very descriptive and worth watching!

PLEASE PLEASE PLEASE give me a like, comment and subscribe! Channel is L8T_BURB

All new vehicles run rich to keep the cats hot, kind of an oxymoron if your focus us efficiency. If he's good at tuning, which it seems like, then you could try for more of a lean tune and see if that helps. I don't think pulling a smigion of fuel out will make any sort of problems, plus it may actually be snappier.

Just a thought.

 

[Thrust]

Sweet! Glad you got it all working. Sounds like you need to make your own kit/tune package to sell for anyone else wanting to do this swap.

 

[TollKeeper]

Wonder how long before someone asks if you want to sell it?

Wanna sell it? J/K!

 

[L8T BURB]

We ran into a little hiccup with the tuning. ECM is still commanding too much fuel, causing a rich condition. We have Kevin Winstead, owner of Big Dog Tuning from Ripley, MS that's going to take a look at the tune file tomorrow and hopefully get it corrected for us. Kevin has done several 6.6 long block swaps so he's very familiar with this setup. We are still very close!

 

[L8T BURB]

Sweet! Glad you got it all working. Sounds like you need to make your own kit/tune package to sell for anyone else wanting to do this swap.

My tech has access to all the tuning stuff, but in his own words, his tuning is "educated guesses". We are now calling on Kevin Winstead from Big Dog Tuning to get the tune dialed in. He quoted just $150 for a remote tune of this application which seems VERY reasonable.

 

[L8T BURB]

Wonder how long before someone asks if you want to sell it?

Wanna sell it? J/K!

I don't even know where I'd start at on a price lol! I plan to be FULLY transparent with all my expenses when I get it back. As much money as I'll have in this, I probably ought to keep it till I die, or I may end up divorced!!

 

[L8T BURB]

Did somebody say cold start???

 

[Trey Hardy]

My tech has access to all the tuning stuff, but in his own words, his tuning is "educated guesses". We are now calling on Kevin Winstead from Big Dog Tuning to get the tune dialed in. He quoted just $150 for a remote tune of this application which seems VERY reasonable.

That’s a very fair price my tuner friend which I’ve known and dealt with for 10+ years usually only charges me 100-150$ mainly for the initial credit to get into HP tuners and 25-50$ for him tuning it for me. Anything after that he usually does for free but I throw him cash for his time and trouble when we have had to adjust stuff

 

[TollKeeper]

Did somebody say cold start???

And your asking how much for it?