Brushless RC8T gearing?

[Ryu James]

so i am building a RC8T and converting it brushless. i have notice that the spur gear on the T is a lot larger than the buggy spur gear. why is this? i have a losi 8 and 8t that are both brushless and both came with 13/48 gearing. i think the RC8T spur is like 54t. i am wondering since i am converting to brushless if i could goto like a 17/50 or a 13/46 setup and be ok for temps? i have 15/48 in my 8t and it screams but temps are great. i dont know what the front and rear gear ratio is in the RC8T though so can anyone recommend the best gearing.
this will be setup with a Tekno Neu 1515 1.5D 2700kv and 5s
i like to go fast.

[brushlessboy16]

holy crap james! a 1.5d on 5s in insane! i would guess that you would need to gear to your track if your racing

Ring and pinion are 43/10 and a 2700 motor on 5s is way overkill

with that motor on 5s with a 13 tooth pinion your speed would be 48 mph

on 4s which is were you should be with that motor puts you at 38 mph

Here is a chart jhautz made for me. i have changed it a bit but its rc8 on the left rc8t on the right just put in your info needed and it will tell you how you should gear it

http://spreadsheets.google.com/ccc?k...IXb3oiedTTqUeQ

[Ryu James]

Originally Posted by cheesecake

Here is a chart jhautz made for me. i have changed it a bit but its rc8 on the left rc8t on the right just put in your info needed and it will tell you how you should gear it

http://spreadsheets.google.com/ccc?k...IXb3oiedTTqUeQ

that spreadsheet doesnt seem to be working.

[Ryu James]

i keep seeing this info (see below) posted around. how do i get my hands on this calculator and can anyone that might have it run a couple of figures?

what is the speed of a Losi8t with 15/48 gearing and 5s on 2700kv?
and what is the differential ratio on the RC8T? i will be running the same 5s on 2700kv and want speeds similar to my losi8t.


(sample from another thread)

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 48
Pinion Tooth Count: 13
Total Voltage: 14.8
Motor KV: 2700
Tire Diameter (inches): 5.8
Tire Ballooning (inches): .2
Motor Current Draw: 0
Motor coil Ω: 0.004
Spur/Pinion Ratio: 3.69 : 1
Total Ratio: 15.87692 : 1
Tire Circumference (inches): 19.48 inches (494.74 mm)
Total Motor Speed: 39960 RPM
Vehicle Speed: 46.42 mph (74.57 km/h)
Estimated Adjusted Speed: 44 mph (70 km/h) - 6% loss
Effective KV Value: 2700
KT constant: 0.5 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

[Matthew_Armeni]

Here you go http://www.scriptasylum.com/rc_speed/index.html

[Ryu James]

Originally Posted by Matthew_Armeni

Here you go http://www.scriptasylum.com/rc_speed/index.html

thanks Matt,
i knew my losi 8t was fast but i havnt been able to radar it. this is telling me 82mph. i actually estimate it being about a 65-70mph truggy.
cant wait to get the RC8T going. now i know which gears to run.
as far as my setup being overkill as others have said.....my reply? "to each their own."