Gearing for 4s and 5s question

i have a similar question... i don't mean to hijack the thread but i thought it would be better to have all the answers in one place...

i'm in the middle of putting together a 8ight buggy conversion together and i'm trying to choose between 4s and 5s... my application will be strictly racing... the difference between a 4s and 5s packs (thunder power 5000's) as far as weight is concerned is 123g... the combo's i'm looking at are to get around 40,000rpm and are as follows

1512/1Y 2750kv on 4s for 40,700 rpm
1512/2.5D 2050kv on 5s for 37,925 rpm

an rtr buggy comes in at bout 3900g and the 123g is less than a 4% increase in the total weight of setup... my question is how much more runtime can i expect out of the 5s setup... the 4s fits better because of its reduced thickness and i'm just wondering if its worth my while to go to 5s...

another question is, given that this is a race setup with runtime and reliability are the goals of the setup, will there be any advantage going to 1515 over the 1512 size motor... the weight difference is only 70g which is less than 2% increase in weight...

[lincpimp]

Less weight is better, but you can use a lower mah battery when going to 5s and get the same runtime, so the battery weight should be almost the same.

There are most likely others here that have more experience with the neu motors than I do, but it appears that many use them on 4s in buggys and like them alot.

1515 seems to be overkill in a buggy, so the reduced weight should be fine. I would like to see someone use a 1509 turning about 50k rpm and geared for track usage. On 5s or 6s so a low kv motor would be required. I have some smaller motors that I will try in my hyper8 on 6s and see how they perform.

[luvsrc]

I recommend NEU 1515 1y with 4s lipo at least with 20c or more rating

[jhautz]

Originally Posted by abiye

i have a similar question... i don't mean to hijack the thread but i thought it would be better to have all the answers in one place...

i'm in the middle of putting together a 8ight buggy conversion together and i'm trying to choose between 4s and 5s... my application will be strictly racing... the difference between a 4s and 5s packs (thunder power 5000's) as far as weight is concerned is 123g... the combo's i'm looking at are to get around 40,000rpm and are as follows

1512/1Y 2750kv on 4s for 40,700 rpm
1512/2.5D 2050kv on 5s for 37,925 rpm

an rtr buggy comes in at bout 3900g and the 123g is less than a 4% increase in the total weight of setup... my question is how much more runtime can i expect out of the 5s setup... the 4s fits better because of its reduced thickness and i'm just wondering if its worth my while to go to 5s...

another question is, given that this is a race setup with runtime and reliability are the goals of the setup, will there be any advantage going to 1515 over the 1512 size motor... the weight difference is only 70g which is less than 2% increase in weight...

I use the 1512/2.5d in a buggy setup. On the track I run it on 4s and for bashing (or a huge track) I can just drop 5s into it. Without changing gearing runtime is about the same, maybe a little less with 5s due to the increased amp draw of the additional motor rpm, but with 5s I am easier on the throttle to keep control so it kinda evens out. But, if you geared it down to run the same top speed, you should theoretically get around 20% more run time since you are using the same amount of energy to accelerate and top speed and there is 20% more potential energy in the same mah 5s pack vs a 4s pack.

The 1512/1y will work fine on 4s, and will probbly feel a little more powerfull than the 1512/2.5d, but it will produce shorter run time as well. I found the 2.5d is more than enough for me. Plus the 2.5d will allow the whole system to run cooler as well.

As far as 1515 vs 1512, I found the 1512 is plenty of motor for a buggy on the track. 1515 isnt necessary and tends to give slighty shorter run times from my experience.