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Internal ratio help???

Internal ratio help???

Old 10-09-2012, 07:48 PM
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Default Internal ratio help???

Do different internal ratios apply power differently? Does it put different loads on the motor? Or is it once I set the rollout it is all the same?

Cheers josh
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Old 10-10-2012, 02:39 AM
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It's all the same.
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Old 10-10-2012, 08:45 PM
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Originally Posted by sosidge View Post
It's all the same.
I agree. I dont know why some people who have no engineering background (hobby shop owners)make comments like how modern cars are better than the older ones becuase of the lower internal ratio,like the so call modern ratio is more suitable for brushless and such. Like for instance many new cars have IR of 2.0 to 1.8 and the older ones from 6 -12 years back was 2.25-2.4

It doesnt matter at all, rollout is the important factor.
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Old 10-10-2012, 09:20 PM
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Originally Posted by alcyon View Post
I agree. I dont know why some people who have no engineering background (hobby shop owners)make comments like how modern cars are better than the older ones becuase of the lower internal ratio,like the so call modern ratio is more suitable for brushless and such. Like for instance many new cars have IR of 2.0 to 1.8 and the older ones from 6 -12 years back was 2.25-2.4

It doesnt matter at all, rollout is the important factor.
The lower ratio will make it easyer to get the needed pinion/spur combo that fits the car to get the needed rollout/FDR. It will not make a differance as to how the power is transferred to the wheels.
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Old 10-10-2012, 09:27 PM
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With the lower ratios, rolling resistance of the cars are much less. The older cars with higher ratios would slow much quicker when off the throttle. But when on the throttle, power delivery was the same regardless of ratios.
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Old 10-10-2012, 09:34 PM
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Originally Posted by trigger View Post
With the lower ratios, rolling resistance of the cars are much less. The older cars with higher ratios would slow much quicker when off the throttle. But when on the throttle, power delivery was the same regardless of ratios.
That is probably becaus the old cars used brushed motors witch have a higher internal rolling resitance compaired to the brushless motors of today.
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Old 10-10-2012, 09:41 PM
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Actually I think it has something about the physics of having a smaller layshaft pulley than today's larger pulleys. I did a comparison back in the day before brushless was around and hand pushed two highly competitive different brushed cars, one with 1.77 and one with 2.25 and the one with the 2.25 had much more resistance. Meaning it wasn't able to go as far.

But i will agree that with today's brushless and practically common ratios between all cars, they're all equal.

Last edited by trigger; 10-10-2012 at 09:55 PM.
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Old 10-10-2012, 10:00 PM
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Originally Posted by trigger View Post
Actually I think it has something about the physics of having a smaller layshaft pulley than today's larger pulleys. I did a comparison back in the day before brushless was around and hand pushed to different brushed cars, one with 1.77 and one with 2.25 and the one with the 2.25 had much more resistance. Meaning it wasn't able to go as far.

But i will agree that with today's brushless and practically common ratios between all cars, they're all equal.
Bearings, motors, belt tention and gear mesh all could make that test inaccurate. One bearing starting to go or a slight differance in gear mesh or belt tension could make a differance in the outcome. A free moving drivtrain will have a lot more efect on the car than will the internal ratio.
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Old 10-10-2012, 10:11 PM
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Originally Posted by BCbud View Post
Bearings, motors, belt tention and gear mesh all could make that test inaccurate. One bearing starting to go or a slight differance in gear mesh or belt tension could make a differance in the outcome. A free moving drivtrain will have a lot more efect on the car than will the internal ratio.
Okeydoky
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Old 10-10-2012, 10:56 PM
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Cool thanks for all your help
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Old 10-11-2012, 05:07 AM
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There is no doubt that bigger pulleys are more efficient, and no doubt that lower internal ratios make it easier to gear stock brushless motors - but that is not the same as saying that a certain internal ratio is better.
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