8.1 liter truck a unicorn?

[braindead]

Lot of people gave me grief for getting a gasser. Turns out the 8.1 is a pretty stout reliable engine. A few I know with diesels are paying pretty high repairs for egrs etc and over $4/gal. I looked for years to find a diesel but most were really beat or wanted a fortune. Ended up just grabbing a gas and so far has been great.

Mines getting a turbo on it just need a few more parts.

View attachment 828622

You going to do a write up on the turbo install? I'd be curious on what setup you're using

 

[Yellowboat]

My dad had the 3/4 ton aztec with one


Carry 2 things with you at all times, a crank sensor ( common oil leak likes to kill them) and a gas card. It sure as hell wont pass a gas station.

 

[ka0tyk]

You going to do a write up on the turbo install? I'd be curious on what setup you're using

gt45 bb turbo rear mounted after the cats. Turbowerx return pump, check valves. Tial wastegate and bov. Just gotta find a set of injectors, intercooler and piping. Have mpiv2 for tuning.

wanted the rear mount because come smog time I can just slap the stock air box back in and tune it down fuel wise. Don’t gotta mess with turbo headers and this and that. Been following a few with rear mounted setups and there’s not much lag. Not looking to make a ton of power or blow doors off at the strip, just give it a little more scoot and butt dyno fun.

 

[wallnutz]

I got an 8.1 in my Moho, it just broke the oil pump drive as it was idling in my driveway when we were getting ready for Glamis. Quick internet search that 2003 it is a fairly common deal.

p.s. only time it ever got better than 7mph was when it was on a hook being towed.

 

[mash on it]

I've run both the 8100 and a 7.3 psd.
I'll pass on an 8100. Fuel alone almost made me go broke.

Dan'l

 

[Bigbore500r]

gt45 bb turbo rear mounted after the cats. Turbowerx return pump, check valves. Tial wastegate and bov. Just gotta find a set of injectors, intercooler and piping. Have mpiv2 for tuning.

wanted the rear mount because come smog time I can just slap the stock air box back in and tune it down fuel wise. Don’t gotta mess with turbo headers and this and that. Been following a few with rear mounted setups and there’s not much lag. Not looking to make a ton of power or blow doors off at the strip, just give it a little more scoot and butt dyno fun.

If your truck is a 2001+ you wont have to do anything to the tune....It's OBD II Scan only. If you ECM is reporting all monitors as "OK / Ready" - you'll pass.
Now, the tech doing the visual inspection, that's a different story

 

[J&k beer can]

Clean 8.1 Suburban;
https://orangecounty.craigslist.org/cto/d/huntington-beach-2005-chevrolet/7039260408.html

Truck: https://sandiego.craigslist.org/nsd/cto/d/san-marcos-2001-chevy-2500hd81l-125k/7036708724.html

So we are the new owners of this unicorn (suburban)
Very clean and well taken care of with all the service paperwork from new.
Was like o crap you posted that add on here....

I think it should tow the boat no problems around havasu and up to lake Mohave and Mead

 

[boatpi]

Congrats, it did look super
Clean.

 

[HubbaHubbaLife]

I have a 2004 Chevy 2500HD LT 2wd LB with the 8.1L and the Allison Tranny. 57k Miles. Original Owner. Yup about 8miles to the gallon with the wind at my back. Pulls my 29' Magic Wizard just great. Only driven to Havasu or the USC Tailgates. View attachment 828559

El Chingon... I like the graphics on your Wizard. Hw's she running for you and what year? Mines an '06 and strong and clean at 500 hours.

 

[ka0tyk]

If your truck is a 2001+ you wont have to do anything to the tune....It's OBD II Scan only. If you ECM is reporting all monitors as "OK / Ready" - you'll pass.
Now, the tech doing the visual inspection, that's a different story

yeah if there’s a giant snail under the hood where a stock air box should be, visual inspection is iffy. I’ve paid in the past for smog inspections for non compliant cars. Other than the oil pump for the return and longer cold side piping it ain’t that much different.

 

[TPC]

Really? 95k miles. I have a Hypertech program, Gibson exhaust, Air raid intake, 4:10 gears.
It does ok even with the lift kit and over size tires but I always felt it should be more

Did it on mine wow what a refresh.
Can’t say it for all but it worked for
Me.

 

[TPC]

Worth changing the up stream 02s

Was that you that recommended it sometime back?
Oh brother what a difference.

 

[TPC]

When the radiator pukes replace with the GM OEM.
I tried 3 aftermarket - all were called the best - all failed.
The OEM is da finess’ kine’. Brutally built.

Uses 1 quart oil w/heavy towing each oil change.

150k miles.
I change the oil every 3k never miss it.
Change the tranny fluid every 30k w/ Transyd.

When you change the SERP belt replace the tensioner. That’s all you need to know.

Mine has the super-rare factory bench front seat. Seats 6 in comfort.
Daughter uses it for her girls trips.
The girls get around 13 mpg to Dizland and back if no traffic.
Same as Grandpas Tundra.

While Waiting for the DMax dually we ordered we used the 8.1 to tow the Toy hauler.
Got 5 to 6 mpg but it hauled the mail.

30 gal tank had to be filled up constantly town to town. An hour on the road after gassed up we started looking for and cueing up the next gas station.

Used the Timbren Hollow rubber springs instead of air bags.
I’ll never use air bags again.

 

[guest hs]

Lot of people gave me grief for getting a gasser. Turns out the 8.1 is a pretty stout reliable engine. A few I know with diesels are paying pretty high repairs for egrs etc and over $4/gal. I looked for years to find a diesel but most were really beat or wanted a fortune. Ended up just grabbing a gas and so far has been great.

Mines getting a turbo on it just need a few more parts.

View attachment 828622

What year is this?

 

[braindead]

So we are the new owners of this unicorn (suburban)
Very clean and well taken care of with all the service paperwork from new.
Was like o crap you posted that add on here....

I think it should tow the boat no problems around havasu and up to lake Mohave and Mead

Congrats, that ride is super clean for its age

 

[ka0tyk]

What year is this?

01.

 

[guest hs]

01.

Want to sell it?

 

[ka0tyk]

Want to sell it?

 

[outboard_256]

gt45 bb turbo rear mounted after the cats. Turbowerx return pump, check valves. Tial wastegate and bov. Just gotta find a set of injectors, intercooler and piping. Have mpiv2 for tuning.

wanted the rear mount because come smog time I can just slap the stock air box back in and tune it down fuel wise. Don’t gotta mess with turbo headers and this and that. Been following a few with rear mounted setups and there’s not much lag. Not looking to make a ton of power or blow doors off at the strip, just give it a little more scoot and butt dyno fun.

Create a build thread for it. Never seen a rear mounted turbo on an 8.1 before. How much boost are you planning to run? Are you going to run stock heads? And your not going to run headers and keep the stock cats? Interested to see how this works out. Rear mounted turbo 8.1 would be a unicorn for sure.

 

[ka0tyk]

Create a build thread for it. Never seen a rear mounted turbo on an 8.1 before. How much boost are you planning to run? Are you going to run stock heads? And your not going to run headers and keep the stock cats? Interested to see how this works out. Rear mounted turbo 8.1 would be a unicorn for sure.

here’s one playing around.

they’re pretty common for silverados. Here you can see it mounted Up. Cold side plumbed back up to the front. Some oil lines and pump to return oil back to the pan. It’s pretty easy to do.

 

[BONER]

^^^Most disappointing Video ever!

 

[Chili Palmer]

Here’s your 25 mpg in a Duramax.
Granted it was just after I filled up and was in traffic doing a constant 30 mph on the freeway. Usually I get about 15-16 mpg. About 13 towing my Howard 22 Offshore at about 70+ mph.

Edit: This is being deleted with a 150hp tune.

 

[River Runnin]

Damn! I Hate This Thread!! .... I sold my Unicorn

 

[sintax]

saw one today, ol @Sharp Shooter was hanging out in the bed of it filming today.

 

[Sharp Shooter]

saw one today, ol @Sharp Shooter was hanging out in the bed of it filming today.

Yep, I've used it for that many times.

 

[ka0tyk]

^^^Most disappointing Video ever!

sorry.

 

[outboard_256]

^^^Most disappointing Video ever!

Kind of what I was expecting. Couldn't even break the tires loose. I would save my money for a blower setup on that engine.

 

[Flying_Lavey]

Kind of what I was expecting. Couldn't even break the tires loose. I would save my money for a blower setup on that engine.

I'd love to take one to Alexi and let him work his magic on it. He seems to get some good power out of the 496's.

Sent from my LM-G710VM using Tapatalk

 

[just_floatin]

I rarely use my one owner 02 (165k) 8.1 Allison unicorn much anymore. Garage queen.

I need to find someone to do the drivers seat or maybe a whole new upholstery. Replaced the entire suspension - 6k this summer installing Cognito everything new GM steering gear, bushing, intermediate shaft, five billstein shocks and new Toyos.

 

[SKIA36]

2004 Suburban 2500 4x4, 8.1 59k original miles, zero issues.

 

[outboard_256]

I'd love to take one to Alexi and let him work his magic on it. He seems to get some good power out of the 496's.

Sent from my LM-G710VM using Tapatalk

I knew a guy with a 8.1 Raylar engine in a drag corvette. The thing was crazy. Obviously not the setup you would want in a towing truck but those engines can produce some crazy power.

http://www.raylarengineering.com/vortec-8100-496cid-forced-induction-performance-parts.html

 

[02HoWaRd26]

Check Facebook, this just popped up and is an 8.1 in Vegas.

 

[02HoWaRd26]

Since i can’t send you the pics via messenger. No number and no miles listed sorry.

 

[Kbach]

I rarely use my one owner 02 (165k) 8.1 Allison unicorn much anymore. Garage queen. View attachment 831642 View attachment 831643 View attachment 831644 View attachment 831645 View attachment 831647 I need to find someone to do the drivers seat or maybe a whole new upholstery. Replaced the entire suspension - 6k this summer installing Cognito everything new GM steering gear, bushing, intermediate shaft, five billstein shocks and new Toyos.

Take a look at eBay. I have a complete set of take off OEM seat covers for mine (04 8.1L CC 2500HD) that I bought a while ago on eBay just in case I ever needed to tidy up the intereior. Probably won't need them considering I've only put about 8k miles on it over the last 6 years or so but at least I've got them if I need them.

 

[ka0tyk]

Getting closer...

 

[DRYHEAT]

Getting closer...

View attachment 839962

Is that an STS kit? I didn’t know they were still around.

 

[ka0tyk]

Is that an STS kit? I didn’t know they were still around.

it’s not a sts kit but will be rear mounted. Should perform just as good for the low boost level I’m aiming for and easy to “hide” when it comes to smog. Detune and pop the original air box in and it’s back to stock.

 

[lbhsbz]

Getting closer...

View attachment 839962

“My 8.1L gets shit mileage”

-Ka0tyk: hold my beer

 

[TPC]

Same mileage as a Toyota Tundra.