godofcable

iTrader: (37)

what kind of track are you running that on Jeff? Here's a link to a video of my track. Small, tight turns, indoor, basically no straights.

http://www.youtube.com/watch?v=rq10Pa4vzyM

GizmoJunkie

iTrader: (5)

Just ball-parking that, 78/22 81/23. Not much top end but tons of kick.

If running no boost can maybe go up a tooth on the pinion.

JEFFs SC10

iTrader: (15)

I run on an outdoor loamy track, has a short straight.

slackomatic

19/78 I would think would be in a hotter motor. My slash with the 26/83 had a FDR of about 8.5. Well if you want more lowend torque then try shooting for a FDR of 9 or 9.5. I ran a FDR of about 10.5 in my 10.5t ballistic and temps were great on a track with lots of stop and go turns.

19/78 in a sc10 will give a FDR of 10.5 roughly. I would gear higher than that in a 17.5t. 21/75 seems to be a close fit at 9.3 FDR.

Here is the site I am using to find the FDR easily. I usually dont pay much attention to the top speed section even though it will be in the ballpark.http://scriptasylum.com/rc_speed/top_speed.html

godofcable

iTrader: (37)

only problem is a lack of motors...unless i just dont know which one to pick...the Novak 17.5 Ballistic wasnt on the list. so the lower the FDR the higher the speed, higher the heat? that about right? whats a good FDR for a small track like the video i posted above?

GizmoJunkie

iTrader: (5)

Correct lower FDR is higher top end, but slower acceleration. Makes more heat for sure, esp if you are under heavier acceleration all the time.

Im thinking you are probly looking at an 9-9.5 FDR for your track in the 17.5 flavor.

godofcable

iTrader: (37)

I'll experiment with picking different motors in the calculation to see if it makes a difference. If it does I'll have to figure out which motor on that list is close to the 17.5 Ballistic since it isn't on the list.

slackomatic

You have probably figured out by just plugging in some different motors that the motor doesnt matter in figuring the FDR. The motor on plays a part in the top speed. The FDR is the final drive ratio. Diff,trans,spur, and pinion are all that matters in figuring the FDR.

Just for figuring on the 17.5 I was using the hobbywing 2300kv. I think its pretty close to the 17.5 ballistic. I also noticed the associated spurs were not in there so I was just using the axial spurs for figuring the FDR.