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-   -   gearing for dirfting (http://www.rcuniverse.com/forum/rc-electric-road-vehicles-race-cars-more-475/11266465-gearing-dirfting.html)

2283kdogg 10-17-2012 04:01 PM

gearing for dirfting
 
hello everybody..name is kevin...

so i want a gear ratio that wont give me alot off speed..im a lil new to dirft and i have a redcat brushless model and it has a 64t spur..

my question is..do i need to go bigger or smaller on the pinion gear for faster aceleraton?? thanks..its currently 64t to 29t<br type="_moz" />

phmaximus 10-17-2012 05:37 PM

RE: gearing for dirfting
 
lets get u on track

divide the number of teeth of the pinion into the number of teeth of the spur gear that will give u there ratio
so say if u are using a 64t spur and a 29t pinion that would be 64/29=2.206896551724138.
That means the pinion gear is doing 2.206896551724138 revolutions per 1 revolution of the spur gear

the higher the number the number the faster it will accelerate but it will decrease the top speed.
Keep in mind it increases the torque at the wheels and more prone to wheel spin.

In general terms
If u fit a Larger pinion gear u will loose acceleration and gain more top speed
If u fit a Larger Spur gear u will increase acceleration and loose top speed
If u fit a Smaller Pinion gear u will increase acceleration and loose top speed
If u fit a Smaller u will loose acceleration and gain more top speed

thats a very basic rule tho

Ive found with some setups and small gear changes that the acceleration is not effected
for example say we are running a 19t pinion and go to a 23t pinion we instantly gain more top speed but....
the acceleration remains the same because the motor draws more amps making it a more powerfull setup, the the extra power from the increased amps produces more torque than before and overcomes the change in gearing

In short the more geared up a BRUSHLESS motor is the more power it produces. but if we go to far we run into heat problems.

Here is the thing tho, max power is produced on takeoff from a dead stop, providing there is traction, as soon as it looses traction the power drops off
U could have a crazy brushless combo thats good for 2hp but a drift car would hardly even use 10% of the available power

Drift cars dont really need much power, all they need is speed, providing u are getting wheel spin easly I would be gearing up for more wheel spinning speed

narwalrus 10-17-2012 05:37 PM

RE: gearing for dirfting
 
If your still running on plastic drift tires, no gearing will change your speed more than 2-5mph.

2283kdogg 10-17-2012 05:45 PM

RE: gearing for dirfting
 

Quote:

ORIGINAL: phmaximus

lets get u on track

divide the number of teeth of the pinion into the number of teeth of the spur gear that will give u there ratio
so say if u are using a 64t spur and a 29t pinion that would be 64/29=2.206896551724138.
That means the pinion gear is doing 2.206896551724138 revolutions per 1 revolution of the spur gear

the higher the number the number the faster it will accelerate but it will decrease the top speed.
Keep in mind it increases the torque at the wheels and more prone to wheel spin.

In general terms
If u fit a Larger pinion gear u will loose acceleration and gain more top speed
If u fit a Larger Spur gear u will increase acceleration and loose top speed
If u fit a Smaller Pinion gear u will increase acceleration and loose top speed
If u fit a Smaller u will loose acceleration and gain more top speed

thats a very basic rule tho

Ive found with some setups and small gear changes that the acceleration is not effected
for example say we are running a 19t pinion and go to a 23t pinion we instantly gain more top speed but....
the acceleration remains the same because the motor draws more amps making it a more powerfull setup, the the extra power from the increased amps produces more torque than before and overcomes the change in gearing

In short the more geared up a BRUSHLESS motor is the more power it produces. but if we go to far we run into heat problems.

Here is the thing tho, max power is produced on takeoff from a dead stop, providing there is traction, as soon as it looses traction the power drops off
U could have a crazy brushless combo thats good for 2hp but a drift car would hardly even use 10% of the available power

Drift cars dont really need much power, all they need is speed, providing u are getting wheel spin easly I would be gearing up for more wheel spinning speed

ok understand..soo if i go bigger on my pinion with my 64t spur..i will get more top speed and if i go smaller on my pinion i will get more aceleration...ok..dropping down like to a 26 make a huge difference?

i saw tha redcat had a model where it was brushless and had a 64t with 26t..thanks for explaining..i really appriciate it..<br type="_moz" />

narwalrus 10-17-2012 05:56 PM

RE: gearing for dirfting
 
Like I said I can't stress enough that I NEED to know if you are running on plastic drift tires...

2283kdogg 10-17-2012 05:58 PM

RE: gearing for dirfting
 
yes i am..i get where your heading..the tires are going to make me drift easy and well there isnt really any need to change gears..is that what you want to say? lol

narwalrus 10-17-2012 06:18 PM

RE: gearing for dirfting
 
Yes, and there is a certain grip threshold  to the tires. No matter how you gear it, there is only a certain acheivable speed which is likely under 5mph gain.

2283kdogg 10-17-2012 08:55 PM

RE: gearing for dirfting
 

Quote:

ORIGINAL: narwalrus

Yes, and there is a certain grip threshold to the tires. No matter how you gear it, there is only a certain acheivable speed which is likely under 5mph gain.

ok...cool..well thanks for making me understand..appriciate it..
<br type="_moz" />

phmaximus 10-19-2012 04:51 AM

RE: gearing for dirfting
 
the main thing to look at that is the biggest factor of drifting is how fast the wheels are spinning during a drift, that plays a massive roll in the handling.

Foxy 10-19-2012 07:43 AM

RE: gearing for dirfting
 
I think it's important to point out here, that we're talking about a drift car. Ph, your info is spot on, but less applicable to drifting. The thing is that in drifting, you want a wide range of wheel speeds, slow with little trigger, for fine tight work, and at the top very very fast, for very sideways sweepers and making corrections when necessary. The wider the range in the middle, the more wheel speeds are available to you. The smaller the range in the middle, the less overall control, but changes in wheel speed with trigger application will be less exaggerated and easier to control. Therefore, you want average to tall gearing, since the lack of torque on acceleration is irrelevant on drift tires, but then you have to consider the rev range of your motor, do you know how many kv it is? To be honest, you're probably best trying to get something going drift-wise using the stock gearing and motor, then see what happens when you add a few teeth to the stock gearing. If I were you I wouldn't be looking to take teeth away, it'll just give you a smaller range of wheel speeds to work with for your drifting. Keep an eye on motor temperatures too, though they aren't usually an issue with drifiting as current draw is low on low traction tires, though motor speeds will be high, so watch out. If you are seeing high temps then consider dropping a few teeth off the pinion, or changing the motor for one with lower kv and higher efficiency.

2283kdogg 10-19-2012 10:24 AM

RE: gearing for dirfting
 

Quote:

ORIGINAL: Foxy

I think it's important to point out here, that we're talking about a drift car. Ph, your info is spot on, but less applicable to drifting. The thing is that in drifting, you want a wide range of wheel speeds, slow with little trigger, for fine tight work, and at the top very very fast, for very sideways sweepers and making corrections when necessary. The wider the range in the middle, the more wheel speeds are available to you. The smaller the range in the middle, the less overall control, but changes in wheel speed with trigger application will be less exaggerated and easier to control. Therefore, you want average to tall gearing, since the lack of torque on acceleration is irrelevant on drift tires, but then you have to consider the rev range of your motor, do you know how many kv it is? To be honest, you're probably best trying to get something going drift-wise using the stock gearing and motor, then see what happens when you add a few teeth to the stock gearing. If I were you I wouldn't be looking to take teeth away, it'll just give you a smaller range of wheel speeds to work with for your drifting. Keep an eye on motor temperatures too, though they aren't usually an issue with drifiting as current draw is low on low traction tires, though motor speeds will be high, so watch out. If you are seeing high temps then consider dropping a few teeth off the pinion, or changing the motor for one with lower kv and higher efficiency.
ok cool..yea i would like to add some teeth to see what happens..the motor is a 540 brushless 3300kv.
but yea..thanks for informing me with these facts...its good to know..like i said , im new to the scene..lol
<br type="_moz" />

2283kdogg 10-19-2012 08:12 PM

RE: gearing for dirfting
 
how many teeth should i add to start with ??...just to see what happens.


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