JK130 | Custom TDI Diesel Parallel Hybrid Jeep Wrangler with composite camper build.

straypoet

Member
A manual box with an electrically assisted column might be even lighter. People use them in all sorts of machines these days
I haven't been able to find one of these that can handle a heavy JK. All of the ones I have found so far seem to be for vehicles under 4Klbs.
I would be interested if I could find one that will do around 6Klbs, as that is my target max weight.

Thank you for the suggestion. :)
 

straypoet

Member
Partial update on the frame extension:

My original plan was to copy a similar frame extension that was done on a Jeep truck project, (Linked earlier in my thread) but after realizing just how heavy that beam would be; and after speaking with the person who did the extension and realizing and that it had some strength problems; I decided to make my own design. I used 3 pieces of structural steel tubing for each frame extension. I used a 2.5"x1.5" 11GA structural tube welded to a 2.5"x2.5" 11ga square structural tube. I then split the side off of another 2.5"x1.5" 11ga tube, and this brought me to the 2.5"x 5/38" that I needed to replicate the original frame section. Each section is 52" long.
This is what the cross-section looks like:
tempImage4kUJHV.jpg

It has taken me quite some time to make these, but I am very happy with their design and strength. I am absolutely convinced that they are stronger than the original inserts. They are heavier, but not nearly as heavy as the design I had been planning on.

Each section weighs about 40lbs.

I installed them so that the two in-tact tubes were on the top, and with the ERW seam at at the top of each tube. The separated tube is the bottom. This should work like a spring truss; as the compression forces will be resisted on top by the 1/4" of steel that are between the top and middle tubes, and the stretching forces resisted by the bottom half-tube.
I believe that the factory front and rear sections will bend before this will.

Each tube is welded along the full length. I used flux-core wire 0.35, and used a high amperage so that I had good penetration. The welds aren't the prettiest welds I have ever made, but as I was using flux-core (welding outside) I am happy with them.

Once I had made the tubes, I then went to insert them into the rear sections of the frame, and because I made these so close to the original, my tolerances are really tight. So much so that I had to use a "Precision installation tool" (8lb sledge.. ;) ) to push the new frame sections into the rear of the frame.


They went in the full 6.5", where they butted up against an internal brace that is a part of the factory rear frame.

Then I started to drive both into the front section..... And I realized that my ratchet straps were too weak, and my "Precision installation tool" had just pulled a muscle. (mine)
So tomorrow I am going to get a couple of come-allongs and pull the frame together.

Here is what it looked like when I left for the day:

IMG_2879.jpeg

I hope to get it pulled fully into place tomorrow, but I probably won't actually weld it together for a few days at least.

Costs:

$215 for the steel ( a bit high, but it seems steel prices are up) (I did find a place cheaper, ($170) but I would have had to take a day off work to go get it, so that wouldn't work)
Also spent $50 at tractor supply for 2 rolls of 0.35 flux-core, and a pack of replacement tips for the welder.
Spent $20 for 10 blades for my little Dremel ultra-saw, and I used almost all of them just cutting the side off of those steel tubes.. Took half the day too. I would like to have used a plasma cutter, but that is just one tool that is going to have to wait.
 
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straypoet

Member
Your documentation is impeccable. How do you find time to work?! Great job, can't wait to see what you do here.

Thank you! I hope that by documenting each step and recording the true cost of the project, that I will be able to inspire others to do this, as I have been inspired myself.

My secret for getting things done is not to sleep; it works well with only mild episodes of blubbering insanity.
 
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straypoet

Member
In other news; my two BSGs (Belt Driven Starter Generator)s arrived, and I took the rear cover off of one to see what was back there, and found this:
tempImageHdkaWM.jpg

As you can see this is obviously a 3phase brushless motor, and the small sensor on the rear is a Commutation Encoder, so that the controller can read the direction and RPM of the motor. There is also a little thermocouple tucked in the side there.

So I figured I would crack open the top cover, and see what kind of control circuitry that I was dealing with.

After a great deal of effort (2 hours worth, as it was very much not made to be EVER opened...), I got it open.....

tempImage7qpN2K.jpg

Yeah, that is about an order of magnitude greater complexity than what I was expecting. I was thinking it would be a pretty standard BLDC controller with maybe some fancy slow-speed control stuff... But no.

I would love to know the full specs of this, but I will have to be satisfied with trying to figure it out by listening to the CANbus messages and looking at the vehicle wiring schematics.
If that fails, I will just have to use an off-the shelf BLDC controller and ditch the factory one.
I just put it back together again...... I will do some more research.
 
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straypoet

Member
Working on a few shorter mock-ups. Trying to make everything fit if I went 5” shorter on the wheelbase.
I pulled the frame to 125", and then stopped. I am going to think about it for a few days before welding. I am thinking I would like to be a bit shorter than the original planned wheelbase, but I am not completely sure yet.
A JT has a 137" wheelbase, and I figured that being 12" shorter at 125" would feel smaller, but once I took a tape measure out, it seemed that my rear axle was too far aft, so I am working on these so that I am completely sure on proportions before welding the frame solid. Looking at the designs below; I think I should center the axle a little further back than the 120".... Maybe 122"? We will see.

I really want to have the full solar array on top, but I also don't want to have a big rear overhang. The breakover angle helps, but it still seems a lot.
Everything is a compromise. I will take this week to decide. Next update will be after the frame is welded and decided.

8428F254-3CA5-4FF1-9EFB-604354C33907.jpeg

Note: The planned width of 75" is just about as wide as I expect the outside of the wheels to be. The Mammoth Boulder wheels have a 4.7" backspace, so added to the axle width, I am at 74.65"

I would rather gain length than width, as some roads are already too narrow. I won't go wider.
 
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kootenay

Intergalacticsuperintendent
My Frontier Pro4x had a 125.9" wheelbase and it was good offroad but it did belly out on a lot of things. Thankfully Nissan made the frame rails the lowest point in the middle of the truck. If I remember correctly the Tacoma is about 1" longer between the wheels on the short wheelbase option. All of this can be overcome with lift height. The rear overhang (departure) on the Frontier was its achilles heel stock but with a high clearance bumper it wouldn't drag off most ledges, to badly.

When it comes to length behind the rear axle remember if you are planning to hang a spare tire or have anything heavy back there (water tank) the distance from the rear will be a problem the further back you go. It will make the Jeep wander like crazy down the road and require much stiffer spring rates and more load on the axle.
 

straypoet

Member
When it comes to length behind the rear axle remember if you are planning to hang a spare tire or have anything heavy back there (water tank) the distance from the rear will be a problem the further back you go. It will make the Jeep wander like crazy down the road and require much stiffer spring rates and more load on the axle.
Weight distribution does concern me. I will have to store my spare somewhere; and I am not much of a fan of having it on my roof, so that is out.
I am currently planning to put the spare recessed on the back of the camper, but there is an alternative that your comment suggests:

An interesting idea would be to put it on the front. The weight of the new engine is less than the original by about 150lbs. The adaptor plate, and the extra weight from the additions to the adaptor plate I am working on will add about 50lbs back to that weight.. So I figure I will be at -100lbs from the stock engine weight.
I plan to weld up a relatively lightweight aluminum front bumper, so integrating the spare into that might actually be a good solution.
seems to have worked before:
1 Airborne Recon Jeep showing front mounted spare wheel, tools and Vickers K Machine Gun i.jpg

I expect the water tank will be around 20 gallons, and would be located under the 'couch' seat, which is going to be behind the drivers seat, above the rear axle. this should hopefully balance the weight against the fridge, and stove which will be on the opposite side.

Again thinking about weight distribution; my plan is to get the jeep moving on it's own power, with the front cab bulkhead built; but not the rear camper, or the front roof.

I will then weigh it, and weigh the front axle separate from the rear. That should give me an idea of where I need to put the weight to keep the balance correct.

I had been hoping for a perfect 50/50 rear/front distribution, but it was suggested that since the front axle isn't as strong as the rear, that going for 60/40 rear/front would be a better goal.

Thank you for your reply, it is encouraging to think you probably did rougher terrain with an equal wheelbase than I likely will with this.
 
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b dkw1

Observer
Most Baja unlimited off road race trucks are 125". Pre-runners are usually under 135" to keep them manageable. I can hustle a crew cab pre-runner down a trail in Baja at a frightening pace.

Go for the extra WB.
 

straypoet

Member
Minor recordkeeping update:
Spent $100 on another Mammoth Boulder open box rim. (Now I only need one more)
Bought 4 Atturo blade XT 35x12.5 R17 tires. $215ea (good deal I think) for a total of $860 (need one more for a spare later in the project)
I bought these tires to try out; they seem to have decent reviews, I will see how they do.

This is my non-project week (I only really get to work on the project every other week), so I spend my free time doing research, and spending money on parts.
I will be back on the project starting after work Friday.
Plans for the coming week are:
  • Finish welding the frame up.
  • Paint the modified areas of the frame.
  • Put new 1/4" stainless or copper-nickel brake lines on the frame, with new nylon stand-offs
  • Drop the body back on the frame temporarily.
  • Get the engine running on the test stand.
Lets see how much of that I actually get finished.

If I get any extra time, I will be working on the adaptor plate for the engine/transmission.
I had a lot of time to think about this part on a very long drive earlier in the week, and I have a solution that I think will work for mounting both of the Belt-Driven-Starter-Generators in a better configuration than originally planned. Lets see how that works out. I will share more once I get to that.

Also, I am leaning away from using the CALB 180ah cells to make up my 48v battery pack, and leaning towards using Tesla model S modules.

I would need 16 CALB batteries in series to get my 48v pack, but only 2 of the tesla modules. (as they are already wired in series internally)

The size and weight advantage is hard to deny. The tesla modules are about 60% the weight and 50% the size of the CALB batteries per kwhr of capacity.
EDIT: I realized later that my math was off, the tesla batteries weigh about the same as the CALB batteries, (but they do have a size advantage; about 30% smaller.)

EDIT#2: also considering Chevy Volt Batteries.


Down side of the tesla batteries is that they are liquid cooled. (Edit: Now that I think about it, I would call that a positive, since I would be able to also use the cooling system in conjunction with the diesel fired heater to warm the batteries and keep them at optimum temp in winter)

Another positive is that each cell is individually fused, and that I would need less cabling to connect the packs.
Looks like a win for the tesla modules. I think I might even be able to fit one or two of the modules under each of the front seats. Maybe.... I will have to do some measurements.
 
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kootenay

Intergalacticsuperintendent
Weight distribution does concern me. I will have to store my spare somewhere; and I am not much of a fan of having it on my roof, so that is out.
I am currently planning to put the spare recessed on the back of the camper, but there is an alternative that your comment suggests:

An interesting idea would be to put it on the front. The weight of the new engine is less than the original by about 150lbs. The adaptor plate, and the extra weight from the additions to the adaptor plate I am working on will add about 50lbs back to that weight.. So I figure I will be at -100lbs from the stock engine weight.
I plan to weld up a relatively lightweight aluminum front bumper, so integrating the spare into that might actually be a good solution.
seems to have worked before:
View attachment 649973

I expect the water tank will be around 20 gallons, and would be located under the 'couch' seat, which is going to be behind the drivers seat, above the rear axle. this should hopefully balance the weight against the fridge, and stove which will be on the opposite side.

Again thinking about weight distribution; my plan is to get the jeep moving on it's own power, with the front cab bulkhead built; but not the rear camper, and the front roof.

I will then weigh it, and weigh the front axle separate from the rear. That should give me an idea of where I need to put the weight to keep the balance correct.

I had been hoping for a perfect 50/50 rear/front distribution, but it was suggested that since the front axle isn't as strong as the rear, that going for 60/40 rear/front would be a better goal.

Thank you for your reply, it is encouraging to think you probably did rougher terrain with an equal wheelbase than I likely will with this.
One of the concepts I was thinking about is your 125" wheelbase idea vs 120" If you keep the body length the same, but by extending the wheelbase you will have less weight behind the rear axle. Making loading and weight bias easier to achieve. I should send you a photo of Wildland fire truck we have on an F550 chassis. The diesel powered fire pump and motor are mounted at and behind the rear axle. Even with it being 2000lbs under GVW it is a handful to drive because the rear bias lifts the front suspension.
 
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nickw

Adventurer
How much do you think the rig is going to end up weighing vs original GVWR? Curious about how you've calculated your spring weights to handle the weight...or maybe it's going to be a bit trail and error?
 

straypoet

Member
How much do you think the rig is going to end up weighing vs original GVWR? Curious about how you've calculated your spring weights to handle the weight...or maybe it's going to be a bit trail and error?
The short answer is that yes, it is trial and error.

The long answer is this:

The back-of-the-envelope math gives me an expected final curb-weight of between 5,000lbs, and 5700lbs. If I leave myself 800lbs of cargo capacity, (myself, food, fuel, some tools ect) the Gross Weight should fall between 5,800lbs and 6,500lbs. I want to be on the LOW SIDE of that number. The JK has a boxed frame; and I believe the frame can handle the weight, the axles maybe are the weak point here.

The curb weight of a manual trans, 2007 Wrangler X is 3,760lbs.
The engine change, the lighter seats, the complete removal of everything behind the front doors, the flat dash ect. I think will put my 'starting weight' at about 3,250lbs.

Obviously that is only an estimate, but once I have the engine in the chassis, and the jeep is moving on it's own power; I will get a weight, and then post it here, but I am pretty confident that 3,250lbs is a good (maybe even conservative) starting number. If accurate; that leaves me somewhere between 1,750-2,450 lbs for all of my camper additions and modifications.

So can I build all this with roughly a 2,000lbs budget? I think I can.

For reference, I understand that the (empty) camper that AEV put on the back of a wrangler (The outpost II) weighed about 750lbs, and that was constructed with a steel frame, I am currently leaning towards an aluminum and composite structure.

I will be taking regular weights (might even get some corner scales), and I will be doing all I can to keep my weight low.

I figure I will order the spring sets to target 6,000lbs If I have to swap.... then I have to swap.

EDIT: I did a little looking around on some JK forums; and there are a lot of JKUs that are running around that are for instance: on 37s, with roof top tents, and roof racks for the tents and lots and lots of armor. There are several threads of people discussing their weights, and posting photos of them running across scales. Many of them are over 7,000lbs. I don't want to be that high; but just for informational purposes; it is good to know that some JKUs are running around at 1,000lbs+ over my target gross.
I can't remember the exact weight (might have to go back and find it), but I remember an episode of Venture4wd (my fav youtuber), where he goes across a scale, and I think he was in the 6,500lbs range. Seeing the kinds of places he goes and the miles he puts on that JKU, I am confident the stretched JK I am building can handle my camper! :cool:
 
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nickw

Adventurer
The short answer is that yes, it is trial and error.

The long answer is this:

The back-of-the-envelope math gives me an expected final curb-weight of between 5,000lbs, and 5700lbs. If I leave myself 800lbs of cargo capacity, (myself, food, fuel, some tools ect) the Gross Weight should fall between 5,800lbs and 6,500lbs. I want to be on the LOW SIDE of that number. The JK has a boxed frame; and I believe the frame can handle the weight, the axles maybe are the weak point here.

The curb weight of a manual trans, 2007 Wrangler X is 3,760lbs.
The engine change, the lighter seats, the complete removal of everything behind the front doors, the flat dash ect. I think will put my 'starting weight' at about 3,250lbs.

Obviously that is only an estimate, but once I have the engine in the chassis, and the jeep is moving on it's own power; I will get a weight, and then post it here, but I am pretty confident that 3,250lbs is a good (maybe even conservative) starting number. If accurate; that leaves me somewhere between 1,750-2,450 lbs for all of my camper additions and modifications.

So can I build all this with roughly a 2,000lbs budget? I think I can.

For reference, I understand that the (empty) camper that AEV put on the back of a wrangler (The outpost II) weighed about 750lbs, and that was constructed with a steel frame, I am currently leaning towards an aluminum and composite structure.

I will be taking regular weights (might even get some corner scales), and I will be doing all I can to keep my weight low.

I figure I will order the spring sets to target 6,000lbs If I have to swap.... then I have to swap.
I know in Australia they can legitimately increase GVWR of the rigs, which they do on some jeeps, may just be a suspension thing or something more substantial? Not sure if they even do axle upgrades....
 
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