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Silverado build 3.0...or should I say 8.1
Posted: Sun Jun 16, 2019 10:52 am
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Sun Jun 16, 2019 3:51 pm
by Rettax3
Pretty awesome. That 8.1 is a beast. I don't know how it stacks up against the 8.0 V-10 Dodge I have, but the fact that it is actually in a
vehicle instead of on a stand in a garage does put you a few steps ahead right there.
And the six-speed is new to me -I've never seen one and had basically written-off anything newer than the '90s trucks from GM as having anything but slush-boxes, unless slugged-down with the 4.3, so incredible find there, congrats! Impatiently waiting to hear some of your ideas.
Re: Silverado build 3.0...or should I say 8.1
Posted: Thu Jul 11, 2019 6:35 pm
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Fri Jul 12, 2019 8:08 am
by 3X00-Modified
ZF6.... You've hug out with Shawn too much...
Re: Silverado build 3.0...or should I say 8.1
Posted: Fri Jul 12, 2019 10:10 pm
by woody90gtz
Hey I created the fake "SS" long before shawn came up with "ZR6". And ZF6 is a real thing... that's the name of the trans. Way more rare than a Z71.
Re: Silverado build 3.0...or should I say 8.1
Posted: Sat Aug 10, 2019 12:25 am
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Sat Aug 10, 2019 6:26 pm
by Rettax3
Looks good! I like those tail-lights, very sharp. Even the headlights look good, usually they just give the truck a pansy-ass duded-up look, but those actually have some class to them, nice job.
Re: Silverado build 3.0...or should I say 8.1
Posted: Sun Dec 01, 2019 10:46 pm
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Sun Dec 01, 2019 10:57 pm
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Sun Dec 01, 2019 11:25 pm
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Fri Dec 06, 2019 9:38 am
by EPfiffner
Congrats on the baby, still finding time to mess around with cars and trucks in true gearhead fashion. The truck looks awesome. Nice how clean it is underneath.
I see the Mullet Camaro on the trailer, I thought it was at the paint shop?
Re: Silverado build 3.0...or should I say 8.1
Posted: Wed Dec 11, 2019 2:45 pm
by woody90gtz
I'm curious to see how long it stays clean. I coated everything liberally with Fluid Film. Heard lots of good things about it. I took the plastic fender liners out and even the gooseneck so I could make sure everything got a good layer.
Camaro update to come later...
Re: Silverado build 3.0...or should I say 8.1
Posted: Wed Dec 11, 2019 3:03 pm
by EPfiffner
I've been using the fluid film as well, but not long enough to provide any success story. Worth a shot in the rust belt, we need any help we can get.
Re: Silverado build 3.0...or should I say 8.1
Posted: Fri Jan 10, 2020 9:25 pm
by woody90gtz
Re: Silverado build 3.0...or should I say 8.1
Posted: Fri Jan 10, 2020 10:03 pm
by woody90gtz
What got me looking at the Android head units is a little discovery from the 8.1 group on Facebook. Some dude has written an app to read and flash early OBD2 GM PCMs for free! And no licensing... (
http://ls-droid.com/) The 411 in my truck is one of the supported computers, so I bought the bluetooth dongle needed and took a look. Total cost: $50...instead of $650 for HPTuners or $800 for EFILIve for $1025. It's mostly for LS swaps using truck computers and harnesses, but plenty of guys have successfully flashed their trucks with it. The tech is 20 years old now, it's about time somebody hacked it! haha
You transfer the .BIN file it saves from your phone to your computer and open it in TunerPro RT, just like the OBD1 stuff. Gearhead-efi has the definitions needed to translate the raw hex code to English and tables. What I found surprised the crap out of me! But I searched the HPTuners forum and confirmed that the factory 8.1 tune only has 15 degrees of timing at WOT and the Power Enrichment mode is essentially turned off (doesn't activate until 90%TPS for 60sec or more). It also has really aggressive "burst knock" retard which pulls timing in anticipation of knock, before the knock sensors even go off. So actual timing at WOT ends up more like 10 degrees usually! I had 28 degrees in my old truck at 9.7:1...and the 496 is only 9.1:1 compression.
Common practice is to turn off burst knock, turn on PE with 0sec delay at about 70%TPS and bump the timing table to 20-24 degrees at WOT. Apparently the Allison automatic tune for the 8.1s has a big dip in the spark table off idle everyone figures is GM's solution for basically traction control. There's also a lot of "torque management" to tame it down for the auto that wasn't in the stock manual tune. I remember my FIL's old 8.1 felt like a gutless POS...that's probably why.
I tweaked a new tune for mine now but haven't flashed it yet, cause I'd like to have a spare PCM around just in case. They're cheap at the junkyard but I haven't gotten to one yet. I guess a bench harness is suggested for flashing too...cause the BCM and stuff can interfere with the flash if you do it in the truck. But that's only like 6 wires and a PCM connector and an OBD2 connector, so that's easy to build. That also lets me clone any truck 4.3/4.8/5.3/6.0 PCM to the 8.1 and flash my modified tune after the clone.
20 degrees at WOT, same table copied for "low octane" table
PE enabled with 0sec delay at 70%TPS with 2 degrees additional spark
Set PE AFR to 12.2 instead of 10.8
Burst knock set to a maximum of 0.5 degrees instead of 5
Set the IAT multiplier tables to only 25%...so at hot IATs it will pull 2 degrees instead of 8
Fixed speedometer for 265s
Set fan controls for when I wire in the elec fans and 180 tstat
I'm figuring that's most of where Blackbear Performance figures +30hp and 40tq for their 8.1 tune!