MatHaas
Silver Member
To the best of my knowledge:
I think it's safe to say the idle speed is set at what the engine was engineered for.
The hydraulic pump is also driven by the engine requiring a certain rpm to properly function. The tractor hydraulics are made to function at idle, requiring a certain optimal minimal RPM. Plus operating them adds a slight load to the engine, which can drop the RPM a little, getting it closer to stall RPM.
As far as "easing" back, that's ultimately dependent on the gear ratio. Yes, slower idle will slow the crankshaft turning the trans, but it is much more dangerous having an engine operating at close to stall RPM. What kind of power do you think your engine makes at 500 rpm? Look at a dyno graph, engine output can multiply several factors at just a 500rpm difference. Especially in a diesel when all of the power occurs on the bottom end in a VERY short RPM range. An engine that stalls out in the middle of you doing a specific task is not what anyone wants, nor should it ever occur if you're operating the tractor properly. You should be able to leave the clutch out and maintain the engine speed. A high compression diesel engine will abruptly shut off when approaching stall RPM. A "slower" RPM is not what your engine was designed around. Too slow of engine speed also decreases cylinder temperatures and increases the likelihood of unburned fuel in the combustion chamber, increasing the risk of it getting past your rings and into the engine oil.
So if anything, mahindra needs a lower first gear or a lower low range ratio. but that's it. don't idle your engine down.
my suggestion and personal technique is to ride the brakes a little and barely engage the clutch. That's as good as it'll get. Factory RPM is set and recommended at 1000 rpm. I wouldn't lower it much beyond that IMO. but that's just my two cents.
don't you have adjustable 3 point with telescoping lower arms on this newer tractor? you don't need to get perfectly lined up; the lower arms have a fair amount of telescoping ability. you just depressed the lock, pull them out, hook it up and back up after it's attached to get it to lock back in.
and what's the logic behind suggesting the idle speed is relevant to how the emissions system functions?
A DOC (diesel oxidation catalyst) "is a flow through filter that contains precious metals to start the oxidation of hydrocarbons, carbon monoxide and unburned fuel and oil." Essentially a catalytic converter if i'm not mistaken (which doesn't require high temps to work, opposed to a DPF). The velocity of exhaust gas moving through it wouldn't change how it works. Though, as aforementioned, a very low idle speed does increase the amount of unburned fuel in the combustion chamber. But the DOC functions the same regardless..
best of luck with improving/adjusting to your situation.
I think it's safe to say the idle speed is set at what the engine was engineered for.
The hydraulic pump is also driven by the engine requiring a certain rpm to properly function. The tractor hydraulics are made to function at idle, requiring a certain optimal minimal RPM. Plus operating them adds a slight load to the engine, which can drop the RPM a little, getting it closer to stall RPM.
As far as "easing" back, that's ultimately dependent on the gear ratio. Yes, slower idle will slow the crankshaft turning the trans, but it is much more dangerous having an engine operating at close to stall RPM. What kind of power do you think your engine makes at 500 rpm? Look at a dyno graph, engine output can multiply several factors at just a 500rpm difference. Especially in a diesel when all of the power occurs on the bottom end in a VERY short RPM range. An engine that stalls out in the middle of you doing a specific task is not what anyone wants, nor should it ever occur if you're operating the tractor properly. You should be able to leave the clutch out and maintain the engine speed. A high compression diesel engine will abruptly shut off when approaching stall RPM. A "slower" RPM is not what your engine was designed around. Too slow of engine speed also decreases cylinder temperatures and increases the likelihood of unburned fuel in the combustion chamber, increasing the risk of it getting past your rings and into the engine oil.
So if anything, mahindra needs a lower first gear or a lower low range ratio. but that's it. don't idle your engine down.
my suggestion and personal technique is to ride the brakes a little and barely engage the clutch. That's as good as it'll get. Factory RPM is set and recommended at 1000 rpm. I wouldn't lower it much beyond that IMO. but that's just my two cents.
don't you have adjustable 3 point with telescoping lower arms on this newer tractor? you don't need to get perfectly lined up; the lower arms have a fair amount of telescoping ability. you just depressed the lock, pull them out, hook it up and back up after it's attached to get it to lock back in.
and what's the logic behind suggesting the idle speed is relevant to how the emissions system functions?
A DOC (diesel oxidation catalyst) "is a flow through filter that contains precious metals to start the oxidation of hydrocarbons, carbon monoxide and unburned fuel and oil." Essentially a catalytic converter if i'm not mistaken (which doesn't require high temps to work, opposed to a DPF). The velocity of exhaust gas moving through it wouldn't change how it works. Though, as aforementioned, a very low idle speed does increase the amount of unburned fuel in the combustion chamber. But the DOC functions the same regardless..
best of luck with improving/adjusting to your situation.
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