New TYM T293

[Jerry/MT]

Yes, the extra 100 rpm at HP measurement might do it, but it wouldn't explain the increased HP at the PTO which is the SAME RPM as the 273. It's not a turbo, so they aren't just dialing up the boost -- so,...what? It's not just an academic question; I have a 273 - which I love dearly (400 hrs and counting). In low gear it has no trouble spinning all 4 tires on dry dirt or packed gravel. It should easily handle larger tires and more HP could only help. Oh, yeah, hydraulic flow appears slightly
higher also. Can that be a result of the extra 100 RPM? Maybe, but I don"t run at that RPM..



Higher ground clearance and a wider stance would be good in my case - 120 year old forest with uneven ground - trail making, minor logging, way more dirt digging and moving than I ever expected...(only because now I CAN, you see).
So can TYM or a dealer or anyone more Knowledgable than me (that doesn't take much) respond with a definative answer?

I'm not a dealer, but I have a background in engines so I'll take a stab.

With diesels or gassers, that have a fixed compression ratio and fixed displacement, power is proportional to airflow. Increasing the rpm will increase the power until the airflow ceases to increase due to increased pressure losses in the induction system and windage losses in the reciprocating components. That's why you see the HP vs rpm curves go flat or even hook over at high rpm. Gassers actually throttle the air flow to control power until thay are at wide open throttle. Diesels do not have a throttle plate. The air induction system is wide open ( except for the airfilter).

With diesels, HP is also proportional to air flow AND fuel to air ratio. So you can "turn up the wick" to get more HP at the same rpm in a diesel. However, the engine and driveline components must be able to withstand the increased power and torque and the engine components have to be capable of withstanding the increased gas pressures and temperatures that go along with the power increases. So my guess is that the increases in power that you are talking about are due to turning up the pump to allow more fuel at a given rpm. In effect, the HP vs rpm curve is incrementally adjusted upward by increasing the max fuel limit in the control.

Hope this helps you understand the power increase.

 

[Bob Christensen]

Thanks, Jerry. I didn't know that about the fuel mixture.
So, I guess the path would be - when my tires are worn out - to get larger tires and wheels, and then if there is a slight lack of power, to crank up the fuel flow a bit.

 

[Jerry/MT]

Thanks, Jerry. I didn't know that about the fuel mixture.
So, I guess the path would be - when my tires are worn out - to get larger tires and wheels, and then if there is a slight lack of power, to crank up the fuel flow a bit.

The caveat is you have to stay within the power and torque limits of the driveline design and the pressure and temperature limits of the engine design or you'll find the weak spots in the tractor.

I see you live in Kingston. I spent my "other life" in the Seattle area - 37 years, 34+ working for the Lazy B as a propulsion engineer. I sure don't miss the traffic!

 

[Bob Christensen]

Yes, well I would hope that TYM has properly calculated that a slight tweak is within the abilities of the engine. If not, I would expect to see multiple posts here from new 293 owners about blown engines long before I wear my tires out and make the change. I suppose one problem would be how to goose it exactly 2 HP without a dyno...

Yes, Kingston is on the other side of Puget sound from Seattle. I haven't gone there in years. Western Montana is also a wonderful place to live, but we both have to figure out what the heck to do about winter.

 

[Tom59]

They obviously conferred with Mitsu about the engines abilities. Crank up the RPM the pump spins faster, hence the pump pumping more.

Simple really.....

2hp isn't going to bend a 2inch thick frame either. The new loader is only a minor tweak up from the 273's also. Same hoe. I kinda like the grill on the 293 more also. Looks meaner...

These things are built to take a measly two more hp which you never use anyway. When is the last time you worked your machine at 2700rpm? I like the larger wheels too. I think they just upped the ante because the new bobcat upped it for them. I wish the bobcat had been a choice when I got mine, I like it. Probably would have stayed -RED- but choice is good.

Lets not get jealous guys our little 273 can do whatever this one can, just not as mean looking.

 

[Gittyup]

Perhaps the HP difference is a consequence of changes in emission requirements that caused manufacturers to adjust the fuel/air mixture. This is what happened with the Kioti CK20. It went from 20 HP to 22 HP.

The bigger tires are just so it looks as big as its competitors in the same hp/weight classes, IMO. Of course, I like the bigger tires and 2 HP is almost 8% more, when and if you need it. Nice "improvements" to this tractor.

 

[Tom59]

Perhaps the HP difference is a consequence of changes in emission requirements that caused manufacturers to adjust the fuel/air mixture. This is what happened with the Kioti CK20. It went from 20 HP to 22 HP.

The bigger tires are just so it looks as big as its competitors in the same hp/weight classes, IMO. Of course, I like the bigger tires and 2 HP is almost 8% more, when and if you need it. Nice "improvements" to this tractor.

Nope, RPM's were raised 1000. Usually when they change emission requirements we lose HP. 2 more hp is on the top of the RPM band so its really not worth much. Not like they got 2 more hp throughout the rpm range. It's just PEAK hp.

Same engine. Mahindra uses it too, but theirs is another 2hp less than ours. Because its 1000 RPM less. 2600rpm redline iirc. it's just a numbers game.

I'm also quite sure the 2800redline is MAX. for this little tiger.

 

[Jerry/MT]

They obviously conferred with Mitsu about the engines abilities. Crank up the RPM the pump spins faster, hence the pump pumping more.

Simple really.....

2hp isn't going to bend a 2inch thick frame either. The new loader is only a minor tweak up from the 273's also. Same hoe. I kinda like the grill on the 293 more also. Looks meaner...

These things are built to take a measly two more hp which you never use anyway. When is the last time you worked your machine at 2700rpm? I like the larger wheels too. I think they just upped the ante because the new bobcat upped it for them. I wish the bobcat had been a choice when I got mine, I like it. Probably would have stayed -RED- but choice is good.

Lets not get jealous guys our little 273 can do whatever this one can, just not as mean looking.

How do you explain the statement that the PTO horsepower went up also? Unless they changed the gears, that occurs at the same engine rpm?

 

[Bob Christensen]

I'm sorry if I seem to be nitpicking, but my intention is to eventually replace my tires with the larger 293s'. If I don't fully understand all the differences
I could make a big mistake. For example, an earlier post here (thanks, Tom59) prompted me to look at loaders. Using the Tym site's compare function, I can see no difference in the loader specs for the two tracters. Yet they are different model names. So now I'm wondering if TYM used the same loader but had to slightly modify it to accomodate the higher stance. I worry that with my 273 on bigger tires I might not be able to reach down as far to dig or use my grapple in the same way.
As for the horsepower issue, It would seem that about 1 of the extra HP can be accounted for by the extra 100 rpm and this wouldn't be useful in practice, but the rest of the gain came through tweaking the air/fuel mixture and would result in increased HP (and torque) throughout the RPM band.
Anybody see any other changes>











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[Tom59]

How do you explain the statement that the PTO horsepower went up also? Unless they changed the gears, that occurs at the same engine rpm?

Not sure I understand the question. What rpm is it measured at? They don't elaborate. These are peak numbers, no?
t273:

Engine HP(kw)-Gross 27(19.8)
PTO HP(kw) 20.7(15.4)
Rated engine speed 2700

t293:

Engine HP(kw)-Gross 29(21.3)
PTO HP(kw) 21.8(16.4)
Rated engine speed 2800