That might work for some folks but I plan on driving this all over, and may not always have access to E85. It'd be nice to just switch between E85 and 93 pump, and let the computer do all the thinking.

I suppose a 2004 Tahoe OS is not a big deal since exceeding 2 bar (14psi) may not be something that the lil 4.8 with stock ring gaps would like! Blessing in disguise?

Is there a P01 OS that can do flex, 3 bar, 80E, and DBC?

unfortunately there is no 3 bar OS for the p01 that can do 80e, flex and DBC...just not enough computing power I guess.

you could scale the tune to make it work, but I havent tried since there is a p59 OS that can do all that

downside: you gotta find a p59, license it, and then license the OS so $200 in credits:(

you'd be amazed at what the little 4.8's can take. I'm sure mine would still be alive if I didn't overheat it beyond the pale

Eh fuck it then, I'll run the P01 with a flex OS that only goes to 2bar.

Side note, I have been recording some POV GoPro vlog videos of me doing some maintenance on this thing, may try to edit some of that stuff and start a Youtube channel.

no its 2 bar absolute, so only one bar positive pressure (above std atmospheric pressure)

Ok, the last step of the "maintenance" of this thing has begun, before I begin really thrashing it. I took it out for NY state inspection and it needed a couple small things, most annoying was the rear parking brake assembly and axle seals. Since the axles have to come out for the seals to be replaced, I figured I'd remove the carrier while I was in there and ditch the G80 locking mechanism, which is very unpredictable and only semi-effective up to 20mph. The guts will come out I'll weld her up and throw it back together. If I decide that the locked rear is a hassle to live with, I'll do my best to murder the 10 bolt while I snag an Explorer 8.8 and get it ready to throw in. Of course this is not my daily driver so I can get away with dumb shit like this.

In other news, the following parts are on the way:
Sloppy Stage 2 cam
PAC 1218s
HD2 Shift kit

For shits and giggles I also licensed the tune and started playing with some stuff. Turned off all Torque management and removed the Power Enrich delay. Since I don't have easy access to a dyno I just did some 20-80mph pulls and used the time needed to accelerate in the log as a benchmark for any performance improvements. Ironically it was nearly identical before and after. I need to get a wideband on this thing sooner or later to see how screwed up the factory mixture is. Also going to throw a $40 sloppy ebay "cold air" kit on it to see what kind of improvements it makes.

IME stock truck tunes dont add enough fuel in PE

There are 6 lug semi float 9.5" 14 bolts out there that people with 1500's swap to.

You can not run a 2004 OS on a 2002 PCM . 2004 is 1MB and the 2002 is 512KB

There is a factory 2002 OS with flex fuel that you can use. Flex fuel equipped Tahoe or Suburban OS# 12216125

thats my fault. I called it an 04 tahoe OS earlier in the thread. i meant 02

Weird because it was commanding 12.2ish when I romped on it, no clue what the actual mixture is because I don't have a WB in it yet.

Appreciate the heads up, I'm still on the fence about upgrading the rear. I'm going to see how long the 10 bolt hangs in there.

Thanks for the heads up, I am pretty clueless when it comes to the PCMs and tuning so any and all input is welcome!

Last night's progress consisted of lots of tedious cleaning and welding. I disassembled the carrier and removed the ring gear so it wouldn't be damaged. Top Gear Top Tip, the ring gear bolts are left hand thread and you'll snap them if you try to use the usual lefty-loosey with an impact gun.

The G80 gov-bomb includes a convenient steel block in the middle that locates everything really nicely.

https://farm2.staticflickr.com/1936/...c86316af_b.jpg

Partially welded, I ended up going back and adding more around the perimeters and to the carrier housing

https://farm5.staticflickr.com/4894/...d8f7f3e8_b.jpg

https://farm2.staticflickr.com/1954/...3fc866a4_b.jpg

https://i.imgflip.com/19xbgu.jpg

haha perfect

and yes that PE throttle % delay is a big one, but also in the eq ratio vs rpm i've seen stock tunes not command 12.5 afr's until 4000 rpm

I usually fatten it up down to 2500 or so, unify the hot and cold tables, crank the enrichment ramp to 3 and drop the rpm delay to under idle, and delay seconds to zero.

Then make some rips and check plugs for spark advance

I thought you had to weld them Installed inside of the housing so you could slide the axle in and install the c clip first, then drop that block in between and the pin through it???

Curious as to the reason for welding the rearend
are you still planning on street use?
I think I would have taken my chances with the Swiss time piece as the carrier will probably break right in half now from the welding heat
and the street manner will be terrible when trying to negotiate any high speed bends
could still be fun for a few days though

welded rears arent real bad mannered until you put on really sticky tires or have to parallel park. all season radials and power steering you hardly even notice.

Here are the logs without changing PE EQ ratio vs rpm, it seems to kick in pretty fast

https://farm5.staticflickr.com/4913/...faf34c74_b.jpg

https://farm5.staticflickr.com/4869/...04cbfc07_b.jpg

That reminds me, I need to get AFR commanded on my histogram list in my config file

No, I did it outside of the car 1) so I wouldn't fill up the axle housing with tons of little BB's and 2) so it would be comfortable because fuck welding upside or on your back. I did weld it with the block, center pin, and lock bolt installed to keep everything aligned so that the axles would be able to slide it when I go to reassemble.
It's not visible in the pictures, but the G80 center block has a nice hole machined through it that allows you to slide the axles through the center of the block (and therefore remove C-clips and axles) without having to remove the block.

https://www.pirate4x4.com/forum/atta...9&d=1180918674

The reason for welding the rear is that the lock/unlock characteristic of the G80 was very unpredictable even under stock 4.8 power levels. One tire fire would randomly turn into semi-lock, then unlock, as I sawed away at the wheel trying to keep up. This way I can guarantee what the rear is going to do :) Carrier won't break in half from "welding heat", it was warm to the touch since it has a ton of thermal mass compared to what I was putting into it. If anything my welds will break first!

Yes, I plan on driving it on the street but certainly not daily. This entire project is a bucket list item for me (try new things and have fun doing it). Recall that I had mentioned I plan on doing an 8.8 swap so if this one blows, I'm not going to be heartbroken about it. See thread title

Attachment 715949


https://ih0.redbubble.net/image.3560...43f4786.u1.jpg

Diff is reassembled with new loctited ring gear bolts, everything torqued to spec and axles are back in. I also threw on a new cover and bolts since the old stuff was crumbling.

https://farm5.staticflickr.com/4825/...9420a85a_b.jpg

It's pretty annoying to have a lift and not be able to use it for this job, since the axle sliding out would hit the far wall with the truck on the lift.

https://farm5.staticflickr.com/4820/...f3175aea_b.jpg

In other news this bad boy (SS2) came in. It'll be a bit before I install it so I lubed it up and stored it in an appropriate sloppy cam bag:

https://farm5.staticflickr.com/4912/...088a4f5d_b.jpg

https://farm5.staticflickr.com/4915/...e5f75b60_b.jpg

https://farm5.staticflickr.com/4831/...5bd6d92a_b.jpg

https://farm5.staticflickr.com/4818/...9c7537b2_b.jpg

Awesome build and I love the work truck picture when you got that motor!