New Camper Build Planning - Considering NPR (USA) - Feedback Welcomed

[luthj]

Greetings,

The wife and I have done a fair bit of overland travel over the years (Aus, NZ, Central America). Started in a tiny VW camper, currently in a 140WB T1N MB sprinter. The sprinter has has served us well for the last 10 years. The buildout and drivetrain are mostly custom at this point. It meets most of our needs quite well, but has a few issues that really can't be resolved on that chassis. Our family may be getting a third, and as I get older, I want a touch more comfort when we are on the road for years at a time.

Specifically we need more space, and I would really like a vehicle that we can keep cool, in 90F/32C+ weather off the grid.

I am still in the early planning stages, going through floor plans, chassis, etc. As with many, I see the advantages of a medium truck platform. Payload, turning circle, reasonably heavy suspension/drivetrain. Putting a 12-13.5' composite box on a 12-14klb GVWR chassis seems like a pretty good compromise. We would likely be using this vehicle for long term international travel for about 10 years on and off. This probably will include a few RORO shipping events, etc. The plan would be as low a profile composite box as reasonable, and try to stay under 22ft length. We can handle the build-out, etc. I am a passable fabricator, but don't have a big shop anymore. I don't relish the idea of manhandling 400lb axles around to DIY a conversion.

I don't want to give up 4WD. I also require low range, or at a least a semi decent crawl ratio otherwise. The more recent Fuso platform doesn't offer low range in the USA, and the duonic trans gives me a bit of heartburn.

The newish NPR seems like it could be a good fit. Single cab with a center seat in our case. It would need converted to 4x4 though. As far as powerplants go I would love some feedback. I have no problem with used trucks, and would probably target a lightly used unit to keep my costs under control.

Powerplants:

• The 5.2L I4 diesel could work. Any experience with reversible DPF/SCR bypass for operation outside North America?
• 6.0L gas is a fairly well know powerplant at this point. Fuel economy is going to be pretty poor.
• 6.6L gas unit is fairly new, but does appear to have somewhat improved fuel economy, and the output is quite nice...

I am curious what vendors offer 4wd conversions? I see that Ridge Rock advertises this service (about $35k?). Not sure what that all includes, and they have sparse details, or even good technical photos. I don't need the ultimate super ride overland mega package, or whatever. Decent ride, 34-37" super singles, and low range will meet my needs fine. Modest improvement in ground clearance would be nice.


Anyways, general feedback on the platform, or related suggestions are welcome. I should mention that we are not ultra wealthy, just engineers with excellent planning skills. My goal would be to do something in the $170k USD range, and expect the project to balloon to about $200k with the typical overruns, and the "might as well while I am in here" stuff.

 

[luthj]

A really quick sketch/model on the 132" WB. 37" tires and a 3" lift. Obviously that is the most recent body style, as that was what I could find in a brief search. 15ft interior box is a bit excessive, but a place to start. 22.5' overall length is a bit more than I want.

 

[gator70]

Mine is close to a finished state.

 

[lanceatm]

A really quick sketch/model on the 132" WB. 37" tires and a 3" lift. Obviously that is the most recent body style, as that was what I could find in a brief search. 15ft interior box is a bit excessive, but a place to start. 22.5' overall length is a bit more than I want.

View attachment 895066

Greetings
Been building them for years Isuzu and Fuso, you will not be disappointed- the newer 6.6 engine does have advantages over the 6.0 . I would not totally exclude the FUSO from your option list. Although no longer sold in the USA the cab/chassis components are pretty easy to get world wide. Dive train is 100% nth American with the Allison gearbox.
We have a full range of interior and exterior accessories - tested and approved.

 

[soaringpotato]

^^ That's going to be your best option if you want a truck with a modern chassis and engine that's turn key.

 

[luthj]

I appreciate the feedback. As mentioned I have some budget constraints. So while quite nice, the EarthCruiser CORE isn't an option at this point, priced at $140K+ for a chassis. Combined with a box and fit-out, total outlay would be $250k+ It also is likely more capability than I need. Of course maybe I am being naive, and by the time I realize my mistake I will have spent that much trying to fix it.

While I do appreciate a good flex/articulation shot as much as the next guy, I am a bit too pragmatic to think I will be doing any real off-roading with a 12klb 10ft tall box-on-wheels (not that you can't, just that I won't). Though I do appreciate the ride improvements which often coincide with off-road performance modifications.

I want/need 4x4 for low traction surfaces, including snow, and low internal cohesion dirt roads. Some sand, such as beach camping, or the occasional sandy wash on a non-improved dirt road for example. Being able to drive out of a campsite that got some rain overnight, and is a bit muddy is a pretty common issue. It isn't a glamorous story to regale my buddies with, but neither is calling for a tow when you are 50ft from pavement!

Low range (or a low enough crawl ratio in 1st gear) is a necessity even when on paved roads, simply to control the vehicle. Momentum isn't my friend with a heavy vehicle. Being able to idle up over medium sized rocks, steps, curbs (even in 2WD low) is incredibly useful in tight quarters. Heck, high altitude hill starts can be a real challenge in high range sometimes, depending on the final drive and powerplant.

I can probably handle a bit less than turn-key, but I likely don't have the time to engineer and fabricate a complete conversion on my own. So as always its trade-offs (as with everything in vehicle based travel!)

 

[SootyCamper]

TL/DR: Gas NPR go with NQR for the Allison, Diesel has deletes available and incredible reliability.


I considered/considering the NPR for a chassis quite heavily. One thing to consider is the transmission for the 6. The gm 8 speed is absolute trash, numerous issues/recalls. Avoid this transmission like the plague.

If you're still interested in the gas npr bump up to the NQR, this gvwr increase gives you the venerable Allison 1000. Realistically you'll be upgrading suspension anyways with the 4x4 conversion. You won't disintegrate your spine with the heavy rated springs.

4x4 conversion can be done by Ridge Rock in Florida. When I spoke to Rolly the proprietor he said it's starts at $28k, one can assume lockers/regearing are all extras. I did find it difficult to get a straight answer on options from him or a quote for that matter. Given the logistics required for me to drive from Alberta to Florida I had to remove them from consideration.

The diesel NPR-hd/XD/NRR with the 5.2 and aisin 6spd dbl overdrive have the best reliability rating I saw (B10 rating of 375,000 miles) . Given that Isuzu has been selling this combo for the last decade,there are deletes available. The 2025 version has some really nice updates for the cab /infotainment. One caveat to this engine is lack of factory dual alternator. Safiery out of Australia is apparently developing a kit.

 

[luthj]

Good info, thanks for posting.

I had a brief email conversation with Ridge Rock, and they gave me a rough estimate of $35k. I believe my original request was to include super singles, and possible a front locker. I asked for more photos, as there is very few technical ones available. And they pointed me to their basically useless Instagram profile. I was told to call Rolly for more discussion. Honestly I struggle with folks that don't want to work at least partially over email. Without stuff in writing, its hard to hold them to account, not to mention it means having to take extensive notes. When it comes to a 4x4 conversion the details really matter. I get that there is quite a bit of customization, but still, I want a bit more communication besides a couple phone calls.

That being said $35k sounds about right for a used/rebuilt D60 in the front with matched Isuzu hubs, new driveshafts, used Tcase and mounting hardware, etc. Add another $35k for a used chassis, and with transport and typical overruns, about $80k. Which isn't obscene. For comparison a brand new Silverado 3500HD 4x4 single cab truck can be configured with a GVWR of 14klbs, and would cost ~$65-70k depending on options. Obviously not a direct comparison, but useful.

As far as suspension changes, I am planning on new leaf springs and bumpstops at a minimum. I would not be opposed to a coil converson long term, but that isn't likely in the cards to start with. I also assume some custom tuned shocks will also be needed to dial in the ride and handling.

I was aware that the 8 speed trans had some issues. I would probably be okay with a 6LE90, but would probably budget it have the unit overhauled at 150k miles or so (or right away in a used rig). I would prefer the Allison obviously.

Good to know delete options are available for the 5.2L. I don't like throwing clouds of soot all over the place, but a clogged DPF or failed NOX sensor in Peru would be quite frustrating.


Does look like Safiery lists an Isuzu N series second alternator. Though its a touch expensive at ~$8kUSD.

ISUZU N Series Second 8-10kW BMG 48V Including Kit and 3000W DC DC to 24V

safiery.com

There is this unit as well, but not sure what engines its compatible with. Anything greater than 2kw of real world output should meet my needs with regards to alternators. So a second 24Vx180A unit would probably be fine.

Second Alternator 24V 180A for Isuzu N Series - Plus Brackets Set to mount

This is a 24V? 180A? Alternator to fit? Isuzu Nseries

safiery.com

 

[Ultimark]

Generally, anything for the N series engines or associated componentry in Australia, will be for the Isuzu 4HK1-TCN, 5,193 cc, 114 kW diesel unit. This is the engine that all NPS Isuzu light trucks use.

While other N series units will have differing power levels of the same engine, and some, or all accessories should fit, the NPS 114 kW engine and drive train is where it is at in Australia. This engine but with the same or higher power output, is used for all the other rear wheel drive N series trucks of comparable gross vehicle mass (GVM). The NPR is the rear wheel drive version of the NPS and unlike the NPS it comes in different wheelbase lengths. The NPS is only available in a medium wheelbase.

I found through this forum that the NPS is sold in South American countries with the steering wheel on the left side; could be a possibility for you.

Also, as you are possibly not that into Isuzu nomenclature, this may help. N is the series, the middle letter gives cabin size as well as GVM, the last letter designates the drive, with R being rear wheel drive and S being a 4x4 configuration.

Mick.