Ok guys i have looked over most of the posts in this section and Have not really come across an answer. I am running the 4300 spec class at my local track. I have been fighting the problem of running out of battery at the 1 min to 30 sec left. I am not the only one with this problem there is atleast 1 other person. My car is really free, and i am actually posting the fastest lap times, I just cant make the 4 min mark. The batteries are new, only one weeks cycle on them now. I have asked what every one is running for gear ratios and have made my adjustments from there. My motor is slightly warmer than when I put it on the track. I plan on breaking out of the mold and trying to go up alot in gearing until my laptimes peak off. Any suggestions would be usefull with out going into all the details of my setup and so on.

Gearing a 4300 with a spec battery should be, gear it so it is the fastest without being to hot when it dumps then back the gear down til it quits dumping. charge your batteries at a lower amp setting like 4.5 and that will help with runtime a little. What size is the track and maybe tell us your rollout or gear and tire size and someone can give you a ball park gear to try.

big gear change with brushless is like 4 teeth so maybe you are just over geared.

-Track size is aprox 185' flat ozite
-I am rolled out at about 2.4 to 2.5 (thats the typical for everyone without Syntered roter))
-I actually run TM race cuts (7" circumfrence), 116 spur, and 40-42 pinions
-my fastest laps are close to 4.22 sec (everyone else is arround 4.4)

Few other notes
I am running an LE lighting and GTB speedo, 4300 with syntered roter. When putting the car on 4 scales (off the top of my head) LR=10.8oz RR=9.2oz LF=12+oz and RF=5oz (keep in mind thoes are off the top of my head) but i am running very little tweak. The car rotates super nice in the turns, and i have tons of speed even out of the turn. Actually laped the field, and was close to getting a second lap on the second place car when I dumped. Looked at the print off of the laptimes, and at the 3 min mark I had dropped to a 4.6sec lap, and at the 3 1/2 min mark I was down to 8+ sec laps. I have been charging my packs at 6 amps, mybe I should drop it and see if that has any affect.

any help is good help, and thanks in advance

overgeared.charge your batts at 4.5-5.0 amps for runtime drop your gear about 3-4 teeth.remember spec batts only have 1600 mah

If you are looking at the black end of the motor I would make sure the tab mark(notch in timing ring) on the timing ring is atleast 1/8th of an inch from the circuit board where the wires solder on and gear down atleast 3 teeth and see where you are at. Turning the timing may not be needed but that is what I would do but most of all 3 teeth less would be a must. 3 teeth less will prob only make a .10 per lap difference up front but you should finish the race and give yourself a chance to win. Gearing up won't work cause you could add 6 or 7 teeth and not be hot but dump at the 2 minute mark.

Good Luck!

When I used the spec 1600's I always charged them at a 4 amp flex charge to keep the heat down, and runtime up. I also changed my driving style, I would let off in the corners for the first 3.5 min. It seemed to really save some battery for the end.

overgeared.charge your batts at 4.5-5.0 amps for runtime drop your gear about 3-4 teeth.remember spec batts only have 1600 mah


Actually I tryed droping that many and dumped even faster, thats why I think I am possibly undergeered. Every where I read, said to go up a couple of teeth with the new rotor, so that also lead me to the conclusion of going up.

What track is running a 4300 BL class with spec batteries????

Actually I tryed droping that many and dumped even faster, thats why I think I am possibly undergeered. Every where I read, said to go up a couple of teeth with the new rotor, so that also lead me to the conclusion of going up.


That is why I said to adjust the timing ring clockwise so when gearing down it won't be screaming at you!

so brian, running a little bit illegal for steel city now are we ????? rotor and speedo gotta go dude !!!!

What track is running a 4300 BL class with spec batteries????


steel city hobbies in the pittsburgh area and freddies in the acron ohio area.

if you go to freddies race in jan. you are not even supposed to have the bearing and rotor upgrade kit in your motor !!

Thanks, Little to far to go play. Ya have fun.

your just a little ways south from here.

so brian, running a little bit illegal for steel city now are we ????? rotor and speedo gotta go dude !!!!


Nothing wrong with the Speedo, as for the rotor, going to experiment with it.

if you go to freddies race in jan. you are not even supposed to have the bearing and rotor upgrade kit in your motor !!


As for freddies, there will be more than 5 people there to run the GTB class, I'm not going to buy another speedo just to run there. freddy said 5 or more and we got our own class.

Besides, there are several GTB's running at SCH, not just me.....

remember spec batts only have 1600 mah

I assume you are using 4 cell/ 1600 spec packs?

WAY back many moons ago, when running a 1400 mah class, we only had 23 amps of power for 4 minutes. I'd guess the 1600 packs MIGHT get you 25 amps for 4 minutes.

It use to be kinda fun to run that limited of a set up

Thanks to all that replied, I had to remove the rotor due to popular demand at the track i race. So now all i have is the endbell upgrade, and seemed to do alot better today, i only dropped off slightly towards the end, and would have 30+ sec left at a 10 amp discharge.

PS, i tryed going down in gearing, and dumperd even faster...ended up going to a 2.62 rollout to make runtime.