a question about bk

[Semi Pro]

so i bought a savage today from a moderator at ultimate as a spair truck for my freinds to run at the track. it has a Feigao 9XL and BK Warrior 9920.

i was planning on useing a 5s pack, how well do you think the set up should run?

i dont know a thing about the bk esc, is it ok?

will this gearing cause to much stress


Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.640953716690042 second gear
Other Ratio: 1
Spur Tooth Count: 47
Pinion Tooth Count: 15
Total Voltage: 18.5
Motor KV: 1853
Tire Diameter (inches): 5.65 maxx crimefighters
Tire Ballooning (inches): .2 is that right?
Motor Current Draw: 0
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 3.13 : 1
Total Ratio: 17.00701 : 1
Tire Circumference (inches): 19.01 inches (482.77 mm)
Total Motor Speed: 34280.5 RPM sounds like a good rpm for a fergo
Vehicle Speed: 36.28 mph (58.28 km/h)
Estimated Adjusted Speed: 35 mph (56 km/h) - 5% loss perfect speed for out track
Effective KV Value: 1853
KT constant: 0.73 oz-in/A


i hit about 35 mph at out track ( tekno/revo) so i was planning on gearing the savage for similar speeds

here is some pics of it, looks like a good truck to me, i will change the battery mounts and clean up the wireing alittle




let me know what you guys think

BK's are decent ESCs. They were the standard about 2-3 years ago. From what I know they can't handle any motors with more than 2 poles very well, and sometimes they can be a pain to program (and have a lack of programming options). They were some of the best of their time though.
Oh, and in case you didn't know, the 99 means it can handle 99 amps, and the 20 means 20 nimh cells. Make sure to use an LVC if you are using LiPo though.

It looks like a great truck though, congrats!

[Semi Pro]

good to know, thanks e-traxxer

so how many poles are the 9xl fergo motors

All the Feigaos that I know of are 2 pole motors, so you should be just fine with that current motor. Just be wary if you want to switch to a Neu or something else, as it may not be such a great combination.

[Semi Pro]

Originally Posted by E-Traxxer

All the Feigaos that I know of are 2 pole motors, so you should be just fine with that current motor. Just be wary if you want to switch to a Neu or something else, as it may not be such a great combination.

good to know, im sure if i were to go nue, i would want a much better esc anyway

Originally Posted by Semi Pro

good to know, im sure if i were to go nue, i would want a much better esc anyway

Agreed, haha.
I also just noticed in the pic that the red battery lead is exposed. It might be a good idea to add another layer of heatshrink to it so that it won't short against the chassis (make sure to cut a hole over the heatsink if you do, so that heat can escape). If you do put some heatshrink on it, make sure that the red jumper located under the red wire is somewhat easily accesible. IIRC, the red jumper is used to program the ESC (taking it off enables programming mode.. I think).

Also, do you know what shock towers those are? I've been looking for something like those...

Edit: if you haven't seen this thread, it'd be a good idea to look, as it details step by step how to progrm your BK esc, as it is a bit complicated.
http://www.rc-monster.com/forum/showthread.php?t=8

[Semi Pro]

thanks for the link, they are older fast lane machine towers, i love there stuff, best warrenty in the buisness

here is the newer ones on mikes site
http://www.rc-monster.com/proddetail...M43000&cat=109

[Serum]

I think i know where you got the idea for that motormount.. :)

[Semi Pro]

Originally Posted by Serum

I think i know where you got the idea for that motormount.. :)

really?

actually i bought the truck already converted. i wanted something that my buddys drive when i go to the track, that way i dont have to let them drive the lsp or the revo.

a guy on urc was selling it and i felt it was a good deal so i grabed it, now i working on some safer battery trays and a better brake system.

is there any way to put 2 steering servos on this chassis without hacking up the shinny stuff? i have a pair of 645mg's that would work great

[Semi Pro]

Originally Posted by Serum

I think i know where you got the idea for that motormount.. :)

lol it does look alot like yours, i like your skid plate set up