It was great to see your rig... it is a very clean and good job... thank you for all your help and info... getting closer to starting mine soon... Blue Skies
Registry 8x Series V8 Swaps (6 Viewers)
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Try mouser electronics.I get all my metri-pak pins and shells from themanyone have a hookup for the sleeve/splice for terminals 82998-12380 as Im diving into my eletrical a couple of the connectors have wires that have popped out, might explain some of my gremlins
11.22 each is a little excessive for a small terminal connection..... I can more than likely sacrifice a few of them and recrimp/solder them to save, but I'd like to have a couple spares
bloc
SILVER Star
I assume you aren't using the GM BCM? Have you had your original voltage gauge working?
I'm planning on integrating the BCM and wonder if it'll allow the PCM to control the alternator appropately. Will probably lay wires into the harness ahead of time in case I need to swap in the 4-wire VR in the future without having to open it back up, just in case it doesn't go as planned. But it would allow me to save $60 on VR and pigtail..
No BCM. The voltage works through the stock gauge (and digitally through the scan gauge).
I have a 2-wire alt plug in the harness and PacFab said it should control it, but I don't see how that's possible without the BCM.
It's been a long time since I looked at what it would take to make it work, but there seemed to be a lot going on in regards to how it determined the charge rate.
bloc
SILVER Star
Do you know if Scangauge will show Current Transmission Gear selection? I've been doing a bit of digging online and can't seem to find a solid answer.
Yeah, I don't have much confidence that simply keeping the BCM communicating with the PCM is enough to provide charge control, but for what I want to do with Cruise/TUTD/Tow-haul it is going to be there anyway. If I plan ahead laying the wires in the harness is easy enough.. and adding the 4-wire VR wouldn't be a lot of work if the BCM doesn't get the job done.
Yeah, I don't have much confidence that simply keeping the BCM communicating with the PCM is enough to provide charge control, but for what I want to do with Cruise/TUTD/Tow-haul it is going to be there anyway. If I plan ahead laying the wires in the harness is easy enough.. and adding the 4-wire VR wouldn't be a lot of work if the BCM doesn't get the job done.
I don't think so. I haven't seen the option in there. They are ancient technology by today's standards though.
As an aside - I have found the gallons used, gallons remaining, and miles-to-empty quite accurate if you calibrate the speed with gps and calibrate the tank with a few fillups. Very handy on trips and multi-day off pavement adventures.
So quick question
Anyone running their vehicles in 4low alot??? That's where I bet 75% of my vehicles life will sit and if so
VSS to the pcm with it being in the trans in a 4l80e has there been any noticeable difference in how the vehicle reacts?? Obviously my tcase reduces me by 3 to 1 so it thinks im going 3 times faster
Also with that said do you just run in manual gear selection
Anyone running their vehicles in 4low alot??? That's where I bet 75% of my vehicles life will sit and if so
VSS to the pcm with it being in the trans in a 4l80e has there been any noticeable difference in how the vehicle reacts?? Obviously my tcase reduces me by 3 to 1 so it thinks im going 3 times faster
Also with that said do you just run in manual gear selection
I did some calculating today and the result was not as good as I thought it would be after reading about other swap MPG. I am still very happy that I did the swap and doubled the HP and nearly doubled the torque. The truck is a pure joy to drive now. The MPG might be more important for others as it was for me in my decision to do the swap. I hear people say they get 17 to 21 MPG in an 80 series LS swap and that might be true as there are a lot of different variations of motor and trans combos to run. I can tell you that the LS3 6.2 crate motor is not the same as a take out from a Cadillac Escalade. These are two different animals and the LS3 crate motor makes more hp and has a more aggressive cam profile. If you want the best milage I suppose the 5.3/6L80E or an Escalade take out combo might work best. I believe what is working against me with my setup is the 5" lift (aerodynamics) with 35" KM2 mud tires, Front Runner rack and awning. On top of that my 80 is a heavy beast. I would think if it were a stock height 80 running michelin LTX tires or something similar with no extra weight added the truck you might get 17 to 18 MPG. I would bet the tires and wheels are my biggest problem for sure. So the reality of my swap is that my city MPG hand calculated averages around 12 mpg. I have not done a highway mpg calculation yet. Some might say that this is not that great but let me say this. I drove this thing to VA from AZ with the stock 4.5 liter and 4 speed trans to get the swap done and my MPG on the highway averaged (hand calculated) only 11.8 with the same setup that I have now. So weight is weight and drag is drag no changes to the truck there. I went from a 4.5 liter with 212 hp / 235 ft. lb. to an LS3 6.2 liter with 430 hp / 424 ft. lb. and get better mileage in the city than I did on the highway. I say this is a win just from the horsepower and torque gain alone. My goal was to have a reliable motor / trans combo that I could find parts for anywhere in the country in a moments notice at any parts store and to be able to pull a small trailer up the mountain passses with ease. Mission accomplished for me.
bloc
SILVER Star
You might be surprised.. On an 08 Tahoe 2wd the 6.2 gets the same freeway MPG as the 4.8, but in town it is 2mpg lower. Another data point, the 5.3 gets 1mpg more on the freeway
That said.. you are right, the LS3 is a different beast than the 6.2 vortec with much more aggressive cam and tuning, and it being set up more for high-rpm power than part-throttle midrange.
Still.. amazing swap. Someone had to run a LS3 to get us a mileage report. Thanks.. hah.
That said.. you are right, the LS3 is a different beast than the 6.2 vortec with much more aggressive cam and tuning, and it being set up more for high-rpm power than part-throttle midrange.
Still.. amazing swap. Someone had to run a LS3 to get us a mileage report. Thanks.. hah.
@azcrackshot 12mpg in town = winning in my book ! My 4.5 doesn't get that good and it has slightly less power.
^^^^ THIS !!!
It is.. "How many smiles per mile" you get.
On my 5.3 Gen III I used to get 18-19 mpg with 31" tires on a stock FJ60 rig.
Move forward with an 80 frame swap, 5" lift, 35" tires, F&R bumpers, Drawer system, and 40+ gal gas tank......
Yeah weight is not your friend... but 100K plus miles after.... I still grin when I drive it........
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If I did it over again I would try to source a take out motor / trans combo with the Computer. Probably an Escalade or maybe from a GM truck. The money savings would be substantial compared to what I went through to source all the parts and make it all play nice together. The 6L80E 1st gear is what makes the LS3 work well on the low end with my setup. I will tell you that it pulls really hard on the top end roll ons. Things happen a little faster now and I definitely have to stay ahead of the truck. I really enjoy driving the 80 now and have learned a lot from this swap that I will apply in future projects.
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My 80 matches your description. I might look into the 38 gallon tank that @sgpipes recommended. I have heard mixed opinions about it.
Voltage regulator swap in progress. Just need to figure out the wiring now.
bloc
SILVER Star
You may have already seen this but the wires themselves are explained here: My 1965 Buick Skylark L92/6L80 Swap - Page 28 - LS1TECH
Side note... I realized that simply installing the BCM with a GENIV swap won't necessarily get the charging stuff right. Looking over pinout sheets I found references to a "battery current sensor" that is wired to the BCM on Gen4 engines. Here's the part on amazon: Amazon.com: ACDelco 10306471 GM Original Equipment Battery Current Sensor: Automotive
I'm assuming it would go on the main ground strap from the block to the first battery on my dual-battery setup.. but I'm hoping that installing and wiring that will allow the 2-wire alternator and its better current management to work.
If not, my backup is to do what @FJ60Cam is doing.
bloc
SILVER Star
One more thing on alternators.. it appears HPTuners can be set up to control the alternator, per this thread: Table for Alternator Control
Without the battery current sensor I don't know how accurate things will be.. but it may be an option to get out of that failsafe 13.8V most people are seeing.
Without the battery current sensor I don't know how accurate things will be.. but it may be an option to get out of that failsafe 13.8V most people are seeing.
The pump that I am running is Chevrolet performance part # 25960709.
alia176
SILVER Star
Since you have the 6L80E, I'd *hope* that your hwy MPG would be pretty decent. Six speeds, wow!!
I think the biggest contributor to the lack of mpg is the heavy wheels and big tires. Also the type of tire (BFG MK2)which have a terrible rollout. I bet if I was stock height and stock tires it would be around 17 mpg. Most guys with late model GM trucks with LS3 motors and big tires and wheels get around 15 mpg. If you want better mpg run a Vortec motor with a 6L80E and keep the truck stock height with little tires. I wanted towing power and a little more fun factor. I am actually considering an LSA supercharger which will net me 600+ hp and much worse milage. I don't use this as my daily driver and after a few weeks with the LS3 I want more!
The Toyota transfer case isn't helping matters either. Don't remember if you are part time or not, but either way the power has to go through a bunch of gears to get to the driveshafts. Each gear pair eats up a percent or two. Start multiplying it all out and those one or two percents start to hurt. Nothing to be done about it, just pointing out one of these conversions using the stock transfer case will never match the efficiency of the stock GM setup.
