Kware33

I am new to the forum and was wondering if anyone has put a castle brushless kit in an old losi xxt. I just put one on and I am wondering if everything is working right. The guy at the hobby shop said it should go 50 mph! It's a 4600 4 pole motor witha sidewinder 3 esc and a 3s lipo. It's my first time with a brushless and a Lipo. I don't think it goes near 50 mph and it does not do wheelies like everyone talks about. Anyone have any info? Is it the gearing? I have a 20 pinion on it now. It's pretty fast and fun to drive, the battery last forever!, but I was thinking it would be faster.....any thoughts?.
thanks

Landrast

I just pulled my XXT out of the closet last night and have been looking up info to do the exact same thing! How's it working out for you? Did you find any help with it?

RustyUs

Should is the key word. If the slipper clutch is set right and tires/wheels are balanced with toe-in at 0 degrees; a tail wind ....if everything (batteries, bearings...etc.) are in top shape... you could hit that 50 mph number, but realistically you should be able to reach 45+ mph with a stadium truck using that 4600kv motor. If you are just doing speed runs, bump up the pinion tooth count.

Kware33

Thanks for the reply. I ended up putting the kit in a rc10gt that I had, a lot like an xxt. I tried playing with the gearing and put a 20 pinion on and it was faster and did wheelies. My radio wasn't set up right, that was a huge difference. The 20 gear was too tall. It had a lot of wheel spin and was hard to control. The 14 pinion seemed to low. I'm running an 18 now. I didn't even run three batteries and already smoked the esc. Castle replaced it no problems within a week so that was cool. I need a way to check the speed. Anybody know a good app? It's really fast but I don't know how fast, it'd be nice to know the mph.
. Landrast, the trans went out in my xxt so I put it in the rc10. It's a lot of fun and much different from when I got the xxt, I'm guessing 1996. The lipo is amazing! I would say I spent around 260$ doing this set up, But much better than the days of waiting for batteries to charge. The battery must last over an hour! I'd say go for it!

phmaximus

Hummmm... It's a worry that the esc went up in smoke... when u get the new esc, be really careful, for the first few battery packs check the ESC and motors temp, every 4min. u should be able to hold ur finger on it for about 3-4 seconds before it starts burning...

as for gearing, u want to set it so the motor runs hot, but won't overheat.... If u ever run on grass, I'd recomend setting the gearing/heat while running it on grass. Because if u do it on a hard surface and then u run it on grass it will most likely run hotter because of the excessive rolling resistance grass causes.

Kware33

That's good info, thanks. I have the new esc in. I ran pretty hard on the 20 pinion and it never got above 103*.mostly street with some grass. It's really cold here in cincy so I am wondering if the air temp cools it down while running.....? I think the spur is 86(stock rc10gt?). I can hold my finger on the motor no problem. Should I go a bigger pinion? The20 was pretty insane, it spun the wheels at any speed and did backflips when throttled hard and got traction. I've never run grass really hard. How long should I run grass before checking? How hard should I run it?

phmaximus

Nice, sounds like it's running nice...

To be safe generally u want to keep the temp under 160f and don't ever let it go past 200f

seeing that u are at 103 u could go up 2-4 teeth on the pinion without any dramatic impact of the heat.

here I'll just quickly cover the basics...

brushless motors are funny.... The more load u place on them, the more powerful they become.... Until u hit the point they are running too hot and u loose all efficency.

so, to increase the power of the motor u need to increase either the voltage(determined by the battery) or the current draw, Amps(determined by the motor and the load placed on it)

so if u gear it up, u will see a power increase aswell as a top speed increase....


While u get use to the car, I'd check it every few min..... And if u can see it's not getting hot, increase the time I between the checking intervals....