you might want to check the wastegate on the big turbo. MOST gas cars from the factory in the era of the turbo bricks, the wastegate actuators were set for 8psi. you can use a boost elbow or an inline boost controller. at 15psi this turbo should be fine, heck it should support 20-22psi. take the hose off the wastegate actuator and see what it spools up to. the egt's should cool down some and the smoke will clear.

 

Here are a couple of pix of my throttle linkage, after the stiffer spring it revs more than I need and the pedal feel is perfect. I now have more power than I need, so next is figuring the best rear gears.

 

Google says the TD04 on the 2.3L Volvo is a 16t model. That's a big turbo. Based on compressor maps, a TD04-9b or TD04-10t would better match the HP output of a turbocharged 2203. When I was researching this a few weeks ago, I found the 9b was fitted stock to a tiny Dodge Colt??? and the 10t was installed in a twin turbo setup on the Dodge Stealth/Mitsubishi 3000GT.

The RHF4 is rated for 45-130 HP in diesel engines, so that'd be a good match. IHI rates the RHF3 up to 100 HP, so you may be reaching the limits of the RHF3, especially considering it was never intended to make more than 60 HP in the OEM Kubota application.

The ball bearing center on the RHF4 sounds great, but would it really matter if you could build boost from off idle?

 

what if you compounded the RHF4 with the TD04..... that would be a nasty little combination right there, boost off the line and the smaller one will help the bigger turbo spool........

 

Turbo6bar, Thanks for the reply on the turbo question! I went and looked at my turbo, it’s a TD04H-13C. I’m still trying to learn the difference in the types of turbos and their model numbers so I can come with a better match. Since I have both turbos and the fabrication wouldn’t be too hard I may take Benjamin’s suggestion and do a compound turbo set up, that would be fun to play with!!! I’ve driven the truck about 200 miles since I put the bigger turbo on it, MPG was identical as with the smaller turbo, however the shims I took out of the injector pump brought the MPG down by about 3-4 MPG, I’m going to put them back in tomorrow.

FTE, I see why your throttle is easy to push, great set up! I may have to go back and re-engineer my throttle, dang thing is hard to push!

 

Update: I reinstalled the (2) injector shims I had removed earlier, this retards the timing. This particular engine only had two shims from the factory. I gained power, EGT’s, boost and a little smother idle. On the other side I lost all the smoke, there is no detectable smoke running down the road now. Every other diesel I’ve worked with always benefited from advancing the timing but not this one. I guess the advance was too much to get a complete burn.

Since putting the two factory shims helped I thought I would add 2 more shims and see what that would do. This raised my EGT’s a little bit beyond where I was comfortable, 1250 or so. It also raised the boost but I didn’t really see a noticeable power increase. So I pulled one of the shims I added back out leaving three. This seems to be a good place, EGT’s are 1150 at their top and boost is running around 9psi. I’m gonna drive it like this awhile to see what it did to the mileage, I’ll post when I have that figure.

 

Good info, thanks for all the R&D you are doing on these motors it has saved me alot of trial and error!

 

YOU,D BE ALOT BETTER OFF WITH A ON ROAD USE 4BT AS THE KUBOTA 4BT IS DESIGNED FOR CONSTANT RUNNING UNLIKE ON ROAD USE ENGINE.
JMO

 

We have made some minor adjustments and it drives just fine.

 

Update: Installed yet another new turbo, this time it’s a Garrett GT17 off a 1999 model Saab 9-5. This turbo is right in the middle, as far as size is concerned, between the other two I have tried. This turbo seems to be perfect for the V2203 engine. It has that nice turbo wine out the tail pipe at idle, spools quickly, builds more boost and lower the EGT’s. The top boost is 11.5 PSI and the top EGT’s are 1000 degrees. This turbo acts and responds like a turbo should.

I’ve also been studying on retarding or advancing the cam timing. The camshafts in these engines have 68 teeth on the gear so if you were to set one tooth back it would equate to 5.3 degrees. Just a thought but I may try it next time I have the front cover off. My next improvement will be getting the injector pump to deliver more fuel. This will require some type of internal modification but I’m not sure exactly what or how yet. I think I’m at the limits of power, boost, and torque without adding fuel.


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BCOWANAWHEELS, you are correct, a road engine would be easier and better BUT, this was an engineering challenge and a lot more fun!! When I started I only knew of JAKE's Kubota-Ranger swap. Bearing that in mind this was kind of Undiscovered country, yeah Star Trek pun. Anyway I haven't worked on a project in a long time that I enjoyed as much as this one and don't misinterpret our post, the trucks are very drivable.