Now that I got my charging issues worked out(lipo batt.),,, how about some advice on gearing for a brushless motor??? I'm using a 87 spur, with a 7.5 motor(LRP) in my T4,,,, what pinion gear should I be using????

I am running a 8.5 in my t4 running a 20- 87 so I would guess around a 18 or 19 for the 7.5.

Is there some kind of chart anywhere that tells what a brushless motor is equal to a brushed motor???? example a 17.5 = to a 21 turn brushed motor?

Tech, thanks again for your help, and I will try the 18 pinion, just don't want to blow up!

I'm glad to read that your charging issues are worked out. I know that first LiPo can be a little scary and you don't want to ruin it or blow anything up. Charging that thing will become 2nd nature after going through the process a few times.

I have a 6.5 LRP Sphere/Vector combo in my T4 and I run 87/17 mostly. I also run 87/18, 84/17, 84/18 and a few other ratios right in that ballpark when I want to *really* dial in the power output based on the track layout and the traction conditions.

Tech's suggestion (18 or 19T pinion) is pretty much right on for your 7.5. Just one tip: Make sure you check the motor & ESC temp often. The extra juice the LiPo provides has a tendency to heat things up fast.

Tim

and use the slipper!!!! BL motors will kill diffs from the torque when you land off jumps so set your slipper up good!a 17.5 is equal to a 27t stock, a 13,5 is equal to a 19t, a 10.5 is equal to a 15t or 16t, a 8.5 is equal to a 12t, from there on down its all about gearing.a 5.5 geared right feels like a 10t brushedor if you under gear it it feels like a 12t with a whole butload more torque over geared it runs like a 8 or 9t, so you see what I am saying.

are these numbers for a stock rotor or the sintered? and does this matter????

max RPM stays the same with either the bonded or sintered rotor, the only thing that changes is the torque curve. so a 8.5 with a bonded rotor will be a little softer out of the hole than an 8.5 with a sintered rotor both running the same gear ratio, but top end will remain the same.

Got the T4 out today, and I must say this thing is makin me smile! Running a LRP 7.5,,,, had 87 spur with a 18 pinion,,,, seemed to me alittle warm, but ran great and did'nt shut off,,,,,,,,,,,,should I try a 16 or 17 pinion, and what kind of temps should I be lookin for???? And is the motor heatsink handy??

If the top end is the same and low end torque is softer in bonded rotor motor, why is the gearing recommendation so much different for the bonded vs sintered? I have a Novak XBR and 13.5 EX and still trying to figure out how to gear in my XXXT. Novak instructions say 4 teeth lower than stock. This seems to be too low based on the previous statements? Not questioning you just trying to figure out where to go. Thanks.

because the bonded rotors do not deal with heat as well as the sintered rotors.heat causes the rotor to loose some of its magnetism. the bonded rotor motors are recomended to be undergeared for this reason, to reduce motor temps and to extend the life of the bonded rotor.you CAN gear a bonded rotor motor the same as a sintered rotor motor and get very similar performance UNTIL the heat starts to effect the magnetic feild of the bonded rotor.

Thanks. I thought heat was the enemy. That is good news because I haven't topped a 100 degrees yet so I think I can gear up some more. Novak says 160 to 170 is a good heat range.

try this if you are having a problem:

http://www.comeseethis.com/gearing/Default.aspx

TeamNovak's NovaGear app

Coming Soon! (http://www.teamnovak.com/)

TeamNovak's NovaGear app

Coming Soon! (http://www.teamnovak.com/)

not good for everyone, not everyone has an ipod, ipad, itouch, or droid (at least i dont ;)).

Thanks. I thought heat was the enemy. That is good news because I haven't topped a 100 degrees yet so I think I can gear up some more. Novak says 160 to 170 is a good heat range.

check with your motor manufacturer for their heat recommendations, although this method may nopt wrok for all motors (getting help from traxxas has been like pulling hens teeth in my case). i read on novaks site to gear it according to temps so i am assuming they mean gear it up till the motor is up to but not higher than 160F. if i remember the page it said something about the motor would have issues after that and if kept running could damage esc as well.


this is what i was reading:

http://teamnovak.com/tech_info/brushless_motor_notice/index.html