kevlar
Addicted to ArboristSite
didn't need to there is no hp gain!
Polishing the Crank
- Thread starter CHEVYTOWN13
- Start date
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didn't need to there is no hp gain!
TotalNZ
ArboristSite Lurker
This is from a local mag, Dirtrider Downunder.
The local dyno guy reckons he's had similar results
The local dyno guy reckons he's had similar results
ROOTSXROCKS
Addicted to ArboristSite
lightening the flywheel may affect Reserve Torque but the majority of the torque is probability in the chain because of its diameter. on the plane of the bar.
Maximum stored energy, vs. weight and total volume, is usually given only for a thin hoop or solid disk. For practical aspect ratios, it is related to the rim's ID/OD ratio by slightly complicated relationships. The ID/OD dependence (below) was derived by combining the above equations with the integral of the differential expression:
d(Inertia) = (Radius)2 (Rim Density) d(Volume)
This leads to the result:
Max ENERGY = (ID/OD Factor) (Rim Volume) (Max Tensile Stress)
where:
(ID/OD Factor) = (1/4) {1 - (ID/OD)4} / {1 - (ID/OD)2}
From this, we get:
(Max ENERGY) / Weight = (ID/OD Factor) (Max Tensile Stress) / (Rim Density)
and (where Total Volume includes the space inside the rim):
(Max ENERGY) / (Total Volume) = (1/4) {1 - (ID/OD)4} (Max Tensile Stress)
but I don't really know polishing my crank sounds like a good idea right now
Maximum stored energy, vs. weight and total volume, is usually given only for a thin hoop or solid disk. For practical aspect ratios, it is related to the rim's ID/OD ratio by slightly complicated relationships. The ID/OD dependence (below) was derived by combining the above equations with the integral of the differential expression:
d(Inertia) = (Radius)2 (Rim Density) d(Volume)
This leads to the result:
Max ENERGY = (ID/OD Factor) (Rim Volume) (Max Tensile Stress)
where:
(ID/OD Factor) = (1/4) {1 - (ID/OD)4} / {1 - (ID/OD)2}
From this, we get:
(Max ENERGY) / Weight = (ID/OD Factor) (Max Tensile Stress) / (Rim Density)
and (where Total Volume includes the space inside the rim):
(Max ENERGY) / (Total Volume) = (1/4) {1 - (ID/OD)4} (Max Tensile Stress)
but I don't really know polishing my crank sounds like a good idea right now
TotalNZ
ArboristSite Lurker
testy sort aren't you.
Got any pics of the CR, they're an awesome bike.
I've got couple in my album, i might start a dirtbike thread.
kevlar
Addicted to ArboristSite
I'm not sure what I make of that report,kinda thinking maybe marketing.but it looks like I stand corrected.
It gained it by inertia it says 1.0 somethin horsepower so it seems I'm assuming that is you lose the low end and gain a lot mid-range to top end where someone on a dirt track would keep it.
I wonder if you compare a weighted bike with a stock or lightened bike on the street with street treads who'd win?
Cause you'd get traction on the street keeping from erratic acceleration with a lightened flywheel vs dirt where it's obvious that the traction (engine control) from the weighted flywheel would win.
But then again these little motors have always had a high power band just thought I'd throw it out there though lol
Definitely interesting info though!
I wonder if you compare a weighted bike with a stock or lightened bike on the street with street treads who'd win?
Cause you'd get traction on the street keeping from erratic acceleration with a lightened flywheel vs dirt where it's obvious that the traction (engine control) from the weighted flywheel would win.
But then again these little motors have always had a high power band just thought I'd throw it out there though lol
Definitely interesting info though!
Terry Syd
Addicted to ArboristSite
Rise time
I really dislike misleading articles like the one above. A flywheel is an energy storing device, it does not make HP.
What these 'technicians' should have done is asked WHY was there an increase in HP. I expect that the engine in question probably had the ignition a bit too far advanced. As the piston moved towards TDC and the ignition sparked, the engine would have to fight against a rapidly expanding chamber pressure.
Without the added flywheel weight the engine would be slowed ever so slightly and peak pressure would be realised BTDC, thus the engine would loose some power by doing more work to compress the gases. By having the extra inertia to overcome the rising pressure the peak of pressure would occur later, perhaps even ATDC.
Note that the effect was greater at peak torque, which is when max volumetric efficiency (faster flame front) occurs.
They could have confirmed the effect to ignition timing by doing another run with a retarded ignition timing. In which case, the bigger flywheel may have produced LESS horsepower as the peak pressure would have occurred later than the light flywheel.
Now a bunch of half-informed readers are going to be running around believing that heavier flywheels make more power - heck, if 10oz is good, why not 10 lbs?
I really dislike misleading articles like the one above. A flywheel is an energy storing device, it does not make HP.
What these 'technicians' should have done is asked WHY was there an increase in HP. I expect that the engine in question probably had the ignition a bit too far advanced. As the piston moved towards TDC and the ignition sparked, the engine would have to fight against a rapidly expanding chamber pressure.
Without the added flywheel weight the engine would be slowed ever so slightly and peak pressure would be realised BTDC, thus the engine would loose some power by doing more work to compress the gases. By having the extra inertia to overcome the rising pressure the peak of pressure would occur later, perhaps even ATDC.
Note that the effect was greater at peak torque, which is when max volumetric efficiency (faster flame front) occurs.
They could have confirmed the effect to ignition timing by doing another run with a retarded ignition timing. In which case, the bigger flywheel may have produced LESS horsepower as the peak pressure would have occurred later than the light flywheel.
Now a bunch of half-informed readers are going to be running around believing that heavier flywheels make more power - heck, if 10oz is good, why not 10 lbs?
kevlar
Addicted to ArboristSite
I was trying to find something in that test that showed why it was flawed but I didn't see it. I'm going to add a 10lb weight to my camaros flywheel so i can gain some peak horse power.yippee!
ROOTSXROCKS
Addicted to ArboristSite
it would be quite helpful if you are running square wheels.
