GMC / Chevy Project Dual Sport ; 1998 GMC Sierra
- Thread starter Greg
- Start date
-
- Tags
- build thread
- Location
- Grand Junction, CO
Hopefully there will be much more of that in the near future.
Cool! Looks right at home on those rocks
Crazy, right?
Thanks Davy! I built a rack to put the RTT over the bed. Over the cab would be great for full-bed access, but I didn't want it up so high & creating a ton of drag.
- Location
- Grand Junction, CO
So another update... I drove the truck up to Utah for NPLD and ended up putting over 600 miles on it between NPLD, visiting family and riding up AF Canyon. Before I made the trip up, I had a few issues to button up... the truck was in bad need of a proper alignment and a steering stabilizer. I found a great local shop for the alignment and started gathering what I needed for a proper stabilizer. I didn't want to use the cheesy looking u-bolts and did NOT want a white stabilizer, so it got painted and I welded the axle bracket on, then used a tube clamp for the tie rod end, after I welded up a mount for the stud on the stabilizer. Here's the final result. -
The truck actually drives amazingly well now... better than it ever has! The steering is still light, but firm and it tracks down the road perfectly!
I hit the road headed up to UT and 5 Mile Pass for NPLD. -
There was a question about MPG earlier in the thread and I hadn't driven the truck enough to give a real answer. That has now changed with over 1000 miles in the last couple weeks! These are all hand calculated, using the GPS for mileage. I'm certain the numbers are quite accurate.
Trip up to Utah... 11 MPG (Freeway & highway with a monster headwind & crosswind from GJ, CO to Price, UT)
Trip back home... 12.5 MPG (Highway & freeway driving, no wind)
Recent Fall Colors Trip... 13.25 MPG! (No freeway driving, highway driving and quite a bit of driving in the dirt & snow)
With the last tank at 13.25 MPG, I could have got 300 miles out of that tank of fuel. I'm pretty happy with that number.
Today we took our annual Fall Colors Tour and the roads were wet and nasty! My tires in the front stick out around 3" past the sheetmetal on each side and I knew it was going to throw mud on the truck.... and I HATE mud! :sick: I'm pretty sure I'll be adding some Bushwhacker fender flares in the future, to prevent slinging dirt all over the truck. I'm not really a fan of flares, but I hate muddy messes even more.
The truck did incredibly well, this was it's first big 4x4 trip and it worked as expected! Most of the driving was in 2WD, then 4 High and 4 Low in a few technical places... we ended up getting into around 6" of snow at 10,500' on Schofield Pass. Even at 20 PSI, the MTR's kicked ass in the snow, I was impressed. We bashed a few deep snow drifts, ascended & descended some steep hills and even found some deep water crossings. All said, I was quite happy with the truck... it was nice to get it out and use for the type off stuff it was intended for... but it's going to be a mess to clean up!
You may have seen some of these in the Trip Report thread....
The truck actually drives amazingly well now... better than it ever has! The steering is still light, but firm and it tracks down the road perfectly!
I hit the road headed up to UT and 5 Mile Pass for NPLD. -
There was a question about MPG earlier in the thread and I hadn't driven the truck enough to give a real answer. That has now changed with over 1000 miles in the last couple weeks! These are all hand calculated, using the GPS for mileage. I'm certain the numbers are quite accurate.
Trip up to Utah... 11 MPG (Freeway & highway with a monster headwind & crosswind from GJ, CO to Price, UT)
Trip back home... 12.5 MPG (Highway & freeway driving, no wind)
Recent Fall Colors Trip... 13.25 MPG! (No freeway driving, highway driving and quite a bit of driving in the dirt & snow)
With the last tank at 13.25 MPG, I could have got 300 miles out of that tank of fuel. I'm pretty happy with that number.
Today we took our annual Fall Colors Tour and the roads were wet and nasty! My tires in the front stick out around 3" past the sheetmetal on each side and I knew it was going to throw mud on the truck.... and I HATE mud! :sick: I'm pretty sure I'll be adding some Bushwhacker fender flares in the future, to prevent slinging dirt all over the truck. I'm not really a fan of flares, but I hate muddy messes even more.
The truck did incredibly well, this was it's first big 4x4 trip and it worked as expected! Most of the driving was in 2WD, then 4 High and 4 Low in a few technical places... we ended up getting into around 6" of snow at 10,500' on Schofield Pass. Even at 20 PSI, the MTR's kicked ass in the snow, I was impressed. We bashed a few deep snow drifts, ascended & descended some steep hills and even found some deep water crossings. All said, I was quite happy with the truck... it was nice to get it out and use for the type off stuff it was intended for... but it's going to be a mess to clean up!
You may have seen some of these in the Trip Report thread....
- Location
- Grand Junction, CO
Are you going to put in those other two diff cover bolts?
No, I was just going to leave them out... you know, save some money on bolts.
The threads completely stripped out in both those holes, I need to helicoil them both. Diff cover is sealing fine in the mean time.
LT.
Well-Known Member
- Location
- Los Alamos, New Mexico
This is such a kick a$$ truck! I don't know what is going on here lately but, there is a number of folks who are building "swiss army" trucks. Greg, this truck is tops! I would sell parts of my body for a truck like yours. One of these days I would love to build a truck like it.
LT.
LT.
OrvisKrawler
Captain Obvious
- Location
- Eden UT
very nice! love the pics! glad to see this getting out and getting used
this pic looks like it could have been an ad for GMC in the late 90's, very cool pic!
this pic looks like it could have been an ad for GMC in the late 90's, very cool pic!
sixstringsteve
Well-Known Member
- Location
- UT
It looks great Greg! I've been missing your 4x4 trip reports lately.
clfrnacwby
Recovery Addict
- Location
- NV
That truck is awesome. Might inspire me to SAS my Tundra soon
- Location
- Grand Junction, CO
I'm just going to put these here....
What is all that? 2 Isuzu 4BD1T's, one that has been torn down and is missing the injection pump, wiring, etc... the other is complete, but has a hole in the side of the block. The transmission and t-case are a 4L80E and a NP241, good upgrades from my current 4L60E and NP243 (electric shift). Everything is getting rebuilt... there is NO timeline for this part of project. It's going to take a lot of money and time to do this right, so I'm not rushing it. Perhaps if things go well, the GMC will be getting a diesel engine next Winter. I do have a pair of 4.10 gears for the HP Dana 60 and the 14 Bolt, which will put me at the right RPM range for the diesel engine.
This Isuzu engine isn't ideal for fitment in truck, as the exhaust drops on the drivers-side... and may interfere with the front driveshaft. I may have to get creative to make it all work, but I think it'll be worth it.
As far as the engine, it's going to get some tweaks in hope of making 450 ft/lbs of torque, (500 ft/lbs would be nice but we will see what's possible). The injection pump will get 'adjusted' for max power, the injectors will be EDM honed for 30% more fuel and I plan on a quality turbo (hopefully a Holset/Cummins HE221 or perhaps some kind of variable nozzle turbo) capable of 30+ pounds of boost. The heads will be getting ARP studs and upgraded valve springs (SBC Z28 springs!) for handling more boost and higher RPM's. It will also be intercooled, making the most of the boost.
So that's the plan... eventually! I'll be updating the thread of course.
What is all that? 2 Isuzu 4BD1T's, one that has been torn down and is missing the injection pump, wiring, etc... the other is complete, but has a hole in the side of the block.
The transmission and t-case are a 4L80E and a NP241, good upgrades from my current 4L60E and NP243 (electric shift). Everything is getting rebuilt... there is NO timeline for this part of project. It's going to take a lot of money and time to do this right, so I'm not rushing it. Perhaps if things go well, the GMC will be getting a diesel engine next Winter. I do have a pair of 4.10 gears for the HP Dana 60 and the 14 Bolt, which will put me at the right RPM range for the diesel engine. This Isuzu engine isn't ideal for fitment in truck, as the exhaust drops on the drivers-side... and may interfere with the front driveshaft. I may have to get creative to make it all work, but I think it'll be worth it.
As far as the engine, it's going to get some tweaks in hope of making 450 ft/lbs of torque, (500 ft/lbs would be nice but we will see what's possible). The injection pump will get 'adjusted' for max power, the injectors will be EDM honed for 30% more fuel and I plan on a quality turbo (hopefully a Holset/Cummins HE221 or perhaps some kind of variable nozzle turbo) capable of 30+ pounds of boost. The heads will be getting ARP studs and upgraded valve springs (SBC Z28 springs!) for handling more boost and higher RPM's. It will also be intercooled, making the most of the boost.
So that's the plan... eventually! I'll be updating the thread of course.
Tonkaman
Well-Known Member
- Location
- West Jordan
Ooooooh I'm in love....
Tacoma
Et incurventur ante non
- Location
- far enough away
Awwww yessssss
I dig it. If you run into needing any 4L80E core parts, I'm yer huckleberry.
I dig it. If you run into needing any 4L80E core parts, I'm yer huckleberry.
- Location
- Grand Junction, CO
400 ft/lbs would be good, 500 would be awesome.
I have thought about something like that...
Wow.... hell yea.
Like I said, it will be awhile... no rush on this aspect of the project. But I am excited for it, the 4BD1T should pull down 20+ MPG and move the truck without a problem.
Awwww yessssss
I dig it. If you run into needing any 4L80E core parts, I'm yer huckleberry.
Sounds good, I'll keep you in mind.
- Location
- Grantsville, Utah
I'm glad you pulled the trigger on the parts, I know you've had this dream for a long time.
The current drivetrain is the only part of your GMC restricting the awesome. These plans should correct that)
The current drivetrain is the only part of your GMC restricting the awesome. These plans should correct that
)
- Location
- Smithfield Utah
Oh boy! This just keeps getting better and better 