That is significantly more than the Kubota, right?
Building a diesel powered RHD TJ Wrangler (Picture Heavy)
- Thread starter RustyAutoholicGuy
- Start date
Hey Grant? What are you going to do with the transfer case clocking on that XJ AW4? The clocking is 23 degrees, and the TJ 231J clocking is 13 degrees. Are you redrilling the mounting holes?
OP
Great question!!! I'm going to be able to adjust the alignment with the NP231-J doubler! Here are some pictures of the doubler!
From this side I can clock the rear NP231 into a multitude of positions. Also the other side has some adjustment as well.
So I'll be able to to adjust the transfer cases to the angles that I need to make everything clear and work! Truthfully I'm hoping to tuck the transfer cases up in the frame so I can increase my ground clearance under my TJ as well!
Thanks
Grant
OP
Hey Guys,
In some exciting news I might be getting another TCU so I can completely control my transmission and have a true automatic transmission that I can configure for my Kubota V2403 diesel engine.
I was disappointed when I started digging into the Microsquirt Transmission Controller to find out that while YES you can make it work, it's basically a massive hack job. I really wish I hadn't bought that controller now, might look to sell it truthfully.
Anyway I'm waiting to hear back from HGM Electronics to confirm it will work with my setup. It's costing a bit more than I was expecting but getting a fully programmable transmission controller for my AW4 automatic would be amazing, especially considering I want to put in some safe guards around the down and up shifting around the transmission!
Also I'm still waiting on motor mounts and my custom transfer case shifters due to inclement weather here in Virginia so I'm still delayed at the moment! I'm hoping to get another video up soon but I'm stuck waiting for parts!
Thanks
Grant
In some exciting news I might be getting another TCU so I can completely control my transmission and have a true automatic transmission that I can configure for my Kubota V2403 diesel engine.
I was disappointed when I started digging into the Microsquirt Transmission Controller to find out that while YES you can make it work, it's basically a massive hack job. I really wish I hadn't bought that controller now, might look to sell it truthfully.
Anyway I'm waiting to hear back from HGM Electronics to confirm it will work with my setup. It's costing a bit more than I was expecting but getting a fully programmable transmission controller for my AW4 automatic would be amazing, especially considering I want to put in some safe guards around the down and up shifting around the transmission!
Also I'm still waiting on motor mounts and my custom transfer case shifters due to inclement weather here in Virginia so I'm still delayed at the moment! I'm hoping to get another video up soon but I'm stuck waiting for parts!
Thanks
Grant
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Very cool! (Both the clocking and the transmission controller) This is a well thought out project.
Can you explain what you're doing with the governor on the Kubota? Will you have some over revving mechanism / protection?
Can you explain what you're doing with the governor on the Kubota? Will you have some over revving mechanism / protection?
OP
So in truth the governor is just two set screws, one for idle and one for maximum rpm, here are some pictures of it on my V2403:
Thanks
Grant
How about the fuel pump and fuel lines, does any of that need to be changed since it's a diesel conversion?
OP
So I'm going to have to remove the electronic fuel pump and figure out a way to bypass it. The V2403 has a mechanical lift pump on it that supplies the fuel injection pump and from what I've been told from KubotaSwappers, it's strong enough to lift the fuel from the gas tank to the engine.
I will be using the both the supply and return lines, the Kubota is interesting in that it does help cool the injectors, from what I remember might be wrong, with the diesel fuel as well so I will be returning that diesel fuel back to the fuel tank.
I will be installing a water separator from a CRD Liberty before the lift pump so I will be filtering the diesel fuel before it reaches the Kubota lift and injection pumps.
Thanks
Grant!
OP
Sorry @Calvin.8 I missed this, and the answer is kind of? The Cummins R2.8 can rev higher, but depending on the turbo setup you go with you would get the same amount of torque from the Kubota as the Cummins engine.
However in terms of my build, YES the Cummins R2.8l is going to have more torque, horsepower and RPM than my Kubota engine. The Cummins is going to be 385ft-lbs of torque and the Kubota is going to be between 300~325ft-lbs of torque, however the Cummins is a larger displacement motor.
Now that I'm thinking about it though, my Kubota V2403 is a IDI engine, if you got a V2203 DI motor, you might be nearly identical in terms of torque with around 350ft-lbs and I would guess horsepower on the DI motor would be like 160ish horsepower. So still down on horsepower but the torque would be really close and with some tuning you could probably match it . . .
-Grant
Good bloody grief that's simple! Outstanding, thanks for the pictures. I'm a visual kind of guy.
I've been reading everything I can find on Kubota into Jeep conversions, and the results always seem to be universally outstanding. No appreciable downside on the freeway other than a slightly decreased top speed, and outstanding performance off road. No issues just putting around either. No reports of broken drive train parts.
The more I research, the more desirable this swap looks for a broad range of Jeep drivers.
Most Jeep TJ transmissions are rated in the 300 ft-lbs torque range for continuous duty, so again, the Kubota is a good match.
OP
Yup exactly! When I first got into this swap it was for my 1947 CJ-2A which is going to be my next build but WAY more complicated than this build because it's a custom frame build truthfully.
There is a guy who has done it in his 1946 Jeep CJ-2A and he has driven his Jeep from California to North Carolina and back. Here is the article about it!
CROSS-COUNTRY AND BACK IN A DIESEL FLATFENDER
I love how simple these engines are, and I love that they are timed with gears and not a belt/chain. I'm really looking forward to seeing how this does in my Wrangler. I miss driving it already. Looking forward to have way more torque and much better fuel economy!
Really the only thing you need to check very carefully is your axle gear ration and tire size to make sure you can easily shift between gears without any issues!
Thanks
Grant
OP
Yup that as well! Honestly the thing that annoyed me the most driving my TJ was going up this long hill near my house. It's about a 1.5 mile long and my TJ was constantly going from 4th gear to 3rd gear where as my Liberty CRD can go up the hill in 5th gear all day long . . . pulling a trailer . . . with my TJ on the trailer.
I'm so looking forward to getting on the highway and just staying in 4th gear regardless if I'm on flat land or going up a grade.
-Grant
Lol, and I've got a grip o'hills to deal with around here.
Well, it's looking more and more like this is a very good idea for my uses Grant. Thanks again for starting this thread and sharing all this information. It may have changed my build plan some. Finish up my suspension mods, do the rest of my interior mods and then plug in the Kubota. Then finish out the armor in steel instead of aluminum (maybe). Whoot!
OP
Hey @StG58 that was my goal from the start, do a completely unusual build but show everyone two things, first show them every time I wrench on my Jeep so they can see what it takes to do one of these swaps and secondly where to get the parts needed to do this swap.
Admittedly mine has gotten a little out of hand because I'm going with a doubler NP231 transfer case setup, but still it's something anyone can do which is the most important part to me!
As for me I would love to go ahead an do a bunch of aluminum upgrades right now! I just don't have the funds at the moment!!!
-Grant
Aluminum can get spendy very quicly. Not everyone does aluminum, and many who do, just copy their steel parts. That's no beuno. Then there's the issue of a lot of aluminum parts being no lighter than the corresponding steel parts. With my SE and the rather anemic 2.5, my goal has always been to shave pounds where I can, or at least not end up adding more weight. It's a lot tougher than it sounds in the TJ world. And a lot more expensive.
I like your solution to graphically document your build. I tried that with my spring and shock refresh using a the camera on my phone and it turned out to be unhelpful. It's very hard to document a dynamic process with static pictures. Doing both yourself. You always seem to miss the best and most important parts.
OK, let's talk gearing and tire size for a minute. Everything I've read so far seems to indicate that the V2203-DI (not your specific engine, but related) likes to cruise around at 2,000 - 2,100 rpm. The best power band seems to be 1,800 to 2,400 rpm. So that's our envelope. Correct? Reasonable? Max seems to be 2,800 to 3,000 rpm. (Just double checking what I've read elsewhere here) so if I select a tire size, say 32x11.50, select a cruising speed in overdrive and then do the math magic I should get an axle gear ratio that gives me that cruising speed at the desired rpm. Then do the math for all the other gears to see if the reasonable 600 rpm available rpm envelope works. (With a little ish in there) Are those reasonable numbers and a reasonable approach? Also, if that's reasonable, would you mind me throwing those calcs and results into your thread?
OP
So first off I've been using Grimm Jeeper Gear Ratio Calculator.
Yes best power between about 1800 ~ 2400 rpm and I've heard cruising is anywhere between 1700 ~ 2300 rpm as well. The best MPG is like 1900 ~ 2100 rpm.
And yes for the rpm envelope as well. There use to be a google spreadsheet somewhere you could enter in your transmission gears, tire size, and axle gears and see the overlap of each gear when it comes to RPM at MPH and I haven't been able to find it which is really unfortunate. I really could use that graph as well.
Some transmission just don't work at all for the massive gap in gears for example the 700r4/4l60e first to second gear is such a massive drop in RPM you would have to rev the Kubota to redline before you could safely go to second gear so it's really just not a viable option.
Yeah on the documentation, it does make everything I do take longer. I have to film the intro, the outro, I have to make sure whatever I'm currently working on I have the GoPro Timelapse pointed at. I remove so much time from my time lapse it's incredible.
On top of all of that, weather and parts being delayed because of weather are really setting me back. I have this coming weekend to work on the Wrangler and then I can't really work on it until after Christmas.
So I'm going to be making a video tonight of all the parts that I currently have, and I'm trying to figure out what I can do work wise on the Wrangler. KubotaSwappers is having to redesign his motor mount plates for the driver (passenger side on a normal Jeep) for the V2403 so I can't mount the engine yet.
So I think I'm going to start taking apart my two NP231s and start building my doubler setup that I'm going to be using. Also I got my new Twin Transfer Case Shift setup in today from JB Custom Fabrication which looks amazing so I will be showing off that setup as well!!!
Thanks
Grant
Very cool Grant, looking forward to the next video. It's too bad about the right side engine mount plate delay, but good that it's getting a redesign.
The grimm jeeper calculator is invaluable for this sort of thing! I've been playing chase the tire size / gear ratio the last little bit. Very interesting.
It's time to start a design notebook.
Take care!
The grimm jeeper calculator is invaluable for this sort of thing! I've been playing chase the tire size / gear ratio the last little bit. Very interesting.
It's time to start a design notebook.
Take care!
I think it would be pretty simple to build a spreadsheet of MPH vs RPM in excel. @StG58 if you want to give me two points in each gear, (maybe 15 and 30 in the lower gears, 30 and 60 in the higher gears) I can VERY quickly create a graph to show the overlaps...
With an auto, things get more difficult due to the torque converter...
With an auto, things get more difficult due to the torque converter...
Thank you for the offer @Ranger_b0b, that's very kind. I've got it covered though. Even though I prefer a good database, busting that out in Excel isn't an issue for me.