Nitro engine dynomometers
03-23-2007 | 09:30 AM
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From: Utica,
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Nitro engine dynomometers
Does anything like this exist? It seems that with the importance of proper tuning, someone would at least have a crude means of taking powerband readings and produced a nitro dyno.
03-23-2007 | 10:46 AM
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03-23-2007 | 08:55 PM
#3
RE: Nitro engine dynomometers
That link above shows some interesting "real world" figures compared to advertising figures 
and are more in line with what I would have expected. Somewhere I've seen a construction article on how to build your own inertia dyno for model engines quite cheaply but I've just spent maybe 2 hours googling and can't find it. I should have bookmarked it 
.
and are more in line with what I would have expected. Somewhere I've seen a construction article on how to build your own inertia dyno for model engines quite cheaply but I've just spent maybe 2 hours googling and can't find it. I should have bookmarked it .
03-24-2007 | 09:19 AM
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RE: Nitro engine dynomometers
I actually found that site after I posted, however they do not offer a dyno for sale.
I thought someone would be offering a complete package dyno system for the hobby by now, it's too simple not too.
I'm no electrical engineer, but how hard can it be? You simply need a way to measure output RPM on the shaft, and time. We know through physics how much energy it takes to accelerate any given amount of mass at any given rate with friction variables added, so that is the simplest part of all - to write the formula.
Now write a measily little program to computate horsepower and torque from this formula and presto, we have ourselves an engine dyno.
Even if the dyno was not completely corrective or accurate, you would still have one very useful device by its comparative uses from the curve it outputs. I.E. If hp was wrong, the curve is still completely correct in showing the creation of the power at its given rpm.
I thought someone would be offering a complete package dyno system for the hobby by now, it's too simple not too.
I'm no electrical engineer, but how hard can it be? You simply need a way to measure output RPM on the shaft, and time. We know through physics how much energy it takes to accelerate any given amount of mass at any given rate with friction variables added, so that is the simplest part of all - to write the formula.
Now write a measily little program to computate horsepower and torque from this formula and presto, we have ourselves an engine dyno.
Even if the dyno was not completely corrective or accurate, you would still have one very useful device by its comparative uses from the curve it outputs. I.E. If hp was wrong, the curve is still completely correct in showing the creation of the power at its given rpm.
03-24-2007 | 09:10 PM
#5
RE: Nitro engine dynomometers
There are many sites that give hints and tips about how to make your own inertia dyno but all that I found earlier were for motor bikes, go karts and cars. However the principle is the same for all of them so any electronics mentioned would be suitable. One site offered the computer programs, another had the maths behind selecting the correct size flywheel etc. The flywheel is the most critical part because it has to be sized to the expected HP of the engine so that it takes around 10 seconds to spin up to full speed from idle. Full speed means around 30,000 revs, not the absolute maximum speed.
03-24-2007 | 10:55 PM
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RE: Nitro engine dynomometers
ORIGINAL: Matt_M
I actually found that site after I posted, however they do not offer a dyno for sale.
I thought someone would be offering a complete package dyno system for the hobby by now, it's too simple not too.
I'm no electrical engineer, but how hard can it be? You simply need a way to measure output RPM on the shaft, and time. We know through physics how much energy it takes to accelerate any given amount of mass at any given rate with friction variables added, so that is the simplest part of all - to write the formula.
Now write a measily little program to computate horsepower and torque from this formula and presto, we have ourselves an engine dyno.
Even if the dyno was not completely corrective or accurate, you would still have one very useful device by its comparative uses from the curve it outputs. I.E. If hp was wrong, the curve is still completely correct in showing the creation of the power at its given rpm.
I actually found that site after I posted, however they do not offer a dyno for sale.
I thought someone would be offering a complete package dyno system for the hobby by now, it's too simple not too.
I'm no electrical engineer, but how hard can it be? You simply need a way to measure output RPM on the shaft, and time. We know through physics how much energy it takes to accelerate any given amount of mass at any given rate with friction variables added, so that is the simplest part of all - to write the formula.
Now write a measily little program to computate horsepower and torque from this formula and presto, we have ourselves an engine dyno.
Even if the dyno was not completely corrective or accurate, you would still have one very useful device by its comparative uses from the curve it outputs. I.E. If hp was wrong, the curve is still completely correct in showing the creation of the power at its given rpm.
03-26-2007 | 09:08 AM
#8
RE: Nitro engine dynomometers
ORIGINAL: Nitro Fumes
Although I don't know the link I once came across a site that had chassis dynos for R/C cars which would be the best way to dyno tune your engine.
Although I don't know the link I once came across a site that had chassis dynos for R/C cars which would be the best way to dyno tune your engine.
chassis dyno is not that good for dynoing your motor... a standalone engine dyno would be way more accurate !
