why horsepower

[1930]

Raspy, that is one fantastic and simple way of explaining torque and horsepower. Thank you very much for that!

If only this stuff was compiled in one place easily accessible to people starting out

 

[Raspy]

Thanks, to both of you guys.

 

[ericm979]

No. The L2501 uses the same direct injection engine design as the L3301 and L3901, and is computer controlled, making any changes much more complex than on a mechanical injection engine. It likely can't be "turned up" easily even with a chip as it looks like a different cam was used, as the displacement and stroke are both smaller on the L2501 than it's bigger brothers.

Look at the parts fiches. The 2501 has a mechanical pump with three high pressure lines to the three injectors, mechanical injectors, and no ECU. The L3301 has a high pressure pump with a single outlet for the common rail, electrical injectors and lists an ECU.

You're correct that turning up an EFI system would be difficult. Unless of course someone cracks the ECU code and makes a tuner. Then it's easy, you just spend money and plug it in. Seems like the market would be too small though.

 

[Fallon]

Look at the parts fiches. The 2501 has a mechanical pump with three high pressure lines to the three injectors, mechanical injectors, and no ECU. The L3301 has a high pressure pump with a single outlet for the common rail, electrical injectors and lists an ECU.

You're correct that turning up an EFI system would be difficult. Unless of course someone cracks the ECU code and makes a tuner. Then it's easy, you just spend money and plug it in. Seems like the market would be too small though.

The L2501 is a tweaked L3200 to play the HP emissions numbers game. My L3200 was mechanical. They made the L2501 specifically to get under the 25hp emissions limits so they could use cheaper (presumably more desirable & reliable) mechanical injection instead of a computer based system.

 

[1930]

Thats what I thought, no ecu

 

[finn1]

B
Ack in the mid 1970’s, one of my first job at the Diesel engine company that hired me for a position in the R&D lab, one of my jobs was to do the master pump settings for Diesel engines. This involved optimizing things like cylinder head swirl, piston bowl geometry, nozzle spray pattern, head gasket thickness, pump retraction valve volume, injection line inside diameter and length, and probably dozens of other variables.

For torque curve shaping, we tried to get a 15% torque rise between the torque at rated speed and at the torque peak, usually 2400-2800 and 1600-1800 rpm, respectively.

Torque peak was usually smoke limited on the relatively low pressure mechanical injected fuel systems of the day.

Power was limited by smoke, and controlled somewhat by engine displacement. All the major manufacturers had families of 3, 4, and 6 cylinder engines, both naturally aspirated and turbocharged, in multiple bores and strokes to give more or less a continuum of power ratings across the ratings.

It was an incredibly complex and wasteful system to manage, but the alternative was to sell only a couple of engine displacements, with multiple ratings. The problem there is that there was no way to make money with that strategy. Many customers would buy the cheapest, lowest power engine and turn up the screw. Things in the drivetrain or cooling system would fail, leaving the manufacturer holding the bag as far as warranty matters.

The advent of electronic controls was a great advancement, power ratings are defined with an electronic calibration, reducing the manufacturing complexity by several orders of magnitude. There is no need for different crankshafts, rods, pistons, etc to cover a power range, and the newer high pressure fuel systems don’t limit fuel delivery for increased torque peak and power like the obsolete mechanical systems.

 

[Molalla1]

B
Ack in the mid 1970’s, one of my first job at the Diesel engine company that hired me for a position in the R&D lab, one of my jobs was to do the master pump settings for Diesel engines. This involved optimizing things like cylinder head swirl, piston bowl geometry, nozzle spray pattern, head gasket thickness, pump retraction valve volume, injection line inside diameter and length, and probably dozens of other variables.

For torque curve shaping, we tried to get a 15% torque rise between the torque at rated speed and at the torque peak, usually 2400-2800 and 1600-1800 rpm, respectively.

Torque peak was usually smoke limited on the relatively low pressure mechanical injected fuel systems of the day.

Power was limited by smoke, and controlled somewhat by engine displacement. All the major manufacturers had families of 3, 4, and 6 cylinder engines, both naturally aspirated and turbocharged, in multiple bores and strokes to give more or less a continuum of power ratings across the ratings.

It was an incredibly complex and wasteful system to manage, but the alternative was to sell only a couple of engine displacements, with multiple ratings. The problem there is that there was no way to make money with that strategy. Many customers would buy the cheapest, lowest power engine and turn up the screw. Things in the drivetrain or cooling system would fail, leaving the manufacturer holding the bag as far as warranty matters.

The advent of electronic controls was a great advancement, power ratings are defined with an electronic calibration, reducing the manufacturing complexity by several orders of magnitude. There is no need for different crankshafts, rods, pistons, etc to cover a power range, and the newer high pressure fuel systems don’t limit fuel delivery for increased torque peak and power like the obsolete mechanical systems.

The short and long of it is . . . if you want to mess with the manufactures settings, buy an old style tractor, it not that hard . . . but the new ones . . . I would not mess with.

 

[wagne223]

When you want maximum performance from the L2501, just pull the throttle lever until it stops. AKA wide open throttle.

Mine then runs at 2400 rpm

It is a different tractor compared to operation at 2100 rpm. (PTO 540 line)

Noticable difference on the rotary cutter.