Kubota L2501 Turbo: A Journey Defined - The Tractor, The Comparison, The Modification, The Results

[Rdrcr]

^^^^
The water is used to cool the PTO Dynamometer during operation. The dealer simply allowed the water to flow out of the machine during testing but, you can hookup a hose to that outlet and direct the water flow if one desired.

Mike

 

[HAR]

Thanks. I suspected for cooling, but it just did not click what was being cooled. Again. Great thread.

 

[diesel466]

Has anyone looked into the new engine in the L2502? Looks like it shares very few parts with the L2501

 

[Rdrcr]

^^^^
It’s still designated a D1703 but, yes, there are some changes to the engine components, including a new injection pump. I haven’t had the opportunity to play with one yet.

Mike

 

[diesel466]

Almost everything in engine is different and I do not see those parts used on any other Kubota, so wondering if they will use it somewhere else.

 

[Rdrcr]

Almost everything in engine is different and I do not see those parts used on any other Kubota, so wondering if they will use it somewhere else.

Here’s what I’ve confirmed regarding the L2501 vs L2502 D1703;

The L2502 has a new updated D1703 engine and Kubota has moved and changed many items under the new hood. First and foremost, the L2502 has a D1703BM-DI-EF04 engine. The previous L2501 has a D1703-M-DI-E4B. The new D1703 has a new diesel injection pump, they’ve moved to oil indicator dipstick to the left (or drivers side) of the engine, the air cleaner assembly has been moved down closer to the battery, there is a fuse box mounting in front of the radiator, and the fuel tank is completely new and repositioned on the right (passenger side) of the engine compartment.

I haven’t seen or heard of any evidence that suggests any internal engine changes.

Mike

 

[diesel466]

Comparing the parts list and diagrams very few parts cross over, the oil pump is now made into the front gearcase, the crank,rods and pistons are different part numbers,the head is a different part number. Cam and lifters are new part numbers, I not sure why but a lot has changed.

 

[Rdrcr]

Comparing the parts list and diagrams very few parts cross over, the oil pump is now made into the front gearcase, the crank,rods and pistons are different part numbers,the head is a different part number. Cam and lifters are new part numbers, I not sure why but a lot has changed.

I'm gonna have to dive into it a bit further when I have some time.

Mike

 

[Rdrcr]

I have some exciting news!

We've had our second successful L2501 Turbo HST Dyno! His L2501 was tested with ambient temperatures of 70 degrees and 100% humidity at sea level. It made 34 PTO HP @ 2,105 RPM with fuel set a 2 1/4 turns!!!! His tractor maintained 1,200 degree EGT's, made 9 PSI of sustained boost and coolant temperatures remained a consistent 200 degrees throughout the dyno session.
He's really happy with the performance of the tractor and the Turbo Kit itself.

By comparison, my L2501 was tested at 42 degrees, roughly 90% humidity and just a couple hundred feet above sea level. My L2501 made 35 PTO HP @ 2,105 RPM with fuel set to 2 1/4 turns.

The only difference between our two L2501 tractors is that his tractor does have the injection timing pump modification. Now, I was personally expecting his tractor to produce more power than mine with the advanced injection timing. But, that wasn't the case and I don't have an explanation.
Regardless, both tractors are producing a TON of additional power and our dyno experiences mirrored one another in terms of performance, output and the positive reaction from those present. Admittedly, I'm just as happy as he is!

We have several L2501 S2T Turbo Kits running now in multiple states and Canada. I'm hoping I can persuade a few more of the L2501 Turbo Kit owners to dyno their tractors too, so I can provide additional comparisons. To be clear, however, some guys are running the Turbo Kits as altitude compensation only and their fuel systems are untouched and unmodified. So there is no fuel adjustment (no additional or increase in fuel). These guys are reporting a restoration of lost power (and a moderate increase in power), a reduction of smoke output and a 200-400 degree reduction of EGT temperatures.

Mike

 

[wmonroe]

Thanks for the update. You’re kits are definitely making some good power and keeping temps in check.