Ftx carnage spur gear and pinion upgrade

[Staggr500fb]

Hi all,
Was wondering if I could get some pointers.
Recently got given my ftx carnage. It's a little bit sluggish on 2s so I've gone up a cell which I've seen people do. But I've heard people needing to change there spur and pinion gears down teeth size. So I've ordered A Hardened steel 49T 32DP spur gear with matched 32DP 13T hardened steel pinion gear. Are these any good or not?

Any help would be appreciated.

 

[tntpoof]

usually, Id just drop the pinion gear .you need to figure if your new gear ratio is really giving you the gear ratio your after. I see breakage to follow this new 3 cell ..

 

[Greywolf74]

Hi all,
Was wondering if I could get some pointers.
Recently got given my ftx carnage. It's a little bit sluggish on 2s so I've gone up a cell which I've seen people do. But I've heard people needing to change there spur and pinion gears down teeth size. So I've ordered A Hardened steel 49T 32DP spur gear with matched 32DP 13T hardened steel pinion gear. Are these any good or not?

Any help would be appreciated.

In this particular case, you only want to drop teeth on the pinion. Dropping teeth on the spur will have the opposite effect of what you want. So for what you're looking to do here you either want to drop teeth on the pinion or add teeth to the spur. Your goal here is to increase your gear ratio. I believe the stock gears are a 23T pinion and a 65T spur gear. This gives you a gear ratio of 2.83 to 1, or 2.83:1. 65 divided by 23 is 2.83 (if you round it off). In other words in order to get the spur to complete 1 full revolution your pinion has to spin 2.83 revolutions. This is where you get 2.83:1 gear ratio.

So we want a little bit higher ratio then this since you moved up to 3S. If we look at the gears you just bought and divide the spur tooth count by the pinion tooth count then you end up with 3.77:1 ratio. So fortunately you dropped enough teeth on the pinion that the drop in teeth on the spur gear still resulted in a higher gear ratio. That being said you likely went higher than you really need to. This will result in a lot of extra torque which will produce a lot of wheelies but will lessen the overall top speed. Now maybe thats OK with you and thats fine, you'll just have to try it and find out. IDK what the rest of the drivetrain gearing is but Id probably be shooting for my gear ratio to be about 3:1 and then see how that works before making further tweaks.

Gearing is something you have to tune and dial in to get the type of performance you want out of it. If it doesn't have enough torque or isnt popping wheelies enough then you'll want to raise your gear ratio. If you have too much of that and you want more top speed then you will need to lower the gear ratio. The key is to not overheat the motor or ESC. Thats how you tune your gearing. When you change gears you should closely monitor the temperatures of the motor and ESC for the first couple/few packs so you know that running WOT a lot during the course of the battery pack wont fry your electronics. You really dont want your motor going much above 165F and 155F for the ESC. If it climbs slightly higher than that when its stopped at the end of a pack thats ok but you dont want it going above that during use. If you dont have one already you'll want to pick up a cheap IR temp gun from Amazon or wherever. You can get them for a little as $15-$20.

One final word of advice. There are a couple of pieces on an RC that shouldnt be metal and one of those is the Spur gear. The other are the A-arms. These pieces should be plastic because they are designed to break and be cheap and easy to replace in the event of a problem or wreck. For example if you have some bearings in your transmission or drive-train that are seized up and causing extra drag then you want to strip that cheap, easy to replace plastic spur gear instead of something much more expensive and time consuming to replace deeper in the drive line.

Hope this helps.

 

[Staggr500fb]

In this particular case, you only want to drop teeth on the pinion. Dropping teeth on the spur will have the opposite effect of what you want. So for what you're looking to do here you either want to drop teeth on the pinion or add teeth to the spur. Your goal here is to increase your gear ratio. I believe the stock gears are a 23T pinion and a 65T spur gear. This gives you a gear ratio of 2.83 to 1, or 2.83:1. 65 divided by 23 is 2.83 (if you round it off). In other words in order to get the spur to complete 1 full revolution your pinion has to spin 2.83 revolutions. This is where you get 2.83:1 gear ratio.

So we want a little bit higher ratio then this since you moved up to 3S. If we look at the gears you just bought and divide the spur tooth count by the pinion tooth count then you end up with 3.77:1 ratio. So fortunately you dropped enough teeth on the pinion that the drop in teeth on the spur gear still resulted in a higher gear ratio. That being said you likely went higher than you really need to. This will result in a lot of extra torque which will produce a lot of wheelies but will lessen the overall top speed. Now maybe thats OK with you and thats fine, you'll just have to try it and find out. IDK what the rest of the drivetrain gearing is but Id probably be shooting for my gear ratio to be about 3:1 and then see how that works before making further tweaks.

Gearing is something you have to tune and dial in to get the type of performance you want out of it. If it doesn't have enough torque or isnt popping wheelies enough then you'll want to raise your gear ratio. If you have too much of that and you want more top speed then you will need to lower the gear ratio. The key is to not overheat the motor or ESC. Thats how you tune your gearing. When you change gears you should closely monitor the temperatures of the motor and ESC for the first couple/few packs so you know that running WOT a lot during the course of the battery pack wont fry your electronics. You really dont want your motor going much above 165F and 155F for the ESC. If it climbs slightly higher than that when its stopped at the end of a pack thats ok but you dont want it going above that during use. If you dont have one already you'll want to pick up a cheap IR temp gun from Amazon or wherever. You can get them for a little as $15-$20.

One final word of advice. There are a couple of pieces on an RC that shouldnt be metal and one of those is the Spur gear. The other are the A-arms. These pieces should be plastic because they are designed to break and be cheap and easy to replace in the event of a problem or wreck. For example if you have some bearings in your transmission or drive-train that are seized up and causing extra drag then you want to strip that cheap, easy to replace plastic spur gear instead of something much more expensive and time consuming to replace deeper in the drive line.

Hope this helps.

So if I just changed the pinion would that just give me enough extra speed without causing too much wheelies? And just stick to the stock spur gear?

 

[Greywolf74]

So if I just changed the pinion would that just give me enough extra speed without causing too much wheelies? And just stick to the stock spur gear?

If you want more top speed then you need to use a bigger pinion or a smaller spur but you dont want to do that until you see if the electronics are going to overheat on 3S with the gearing you currently have.