I just put an LRP AI system with the 15.5 BL motor in my T4 and a 19t brushed in my sons T4. We are both running 3300 6cell NiMh batteries.

15.5 BL Spur 90 Pinion 23 Motor Temp after 4 min 91F


19t Spur 84 Pinion 18 Motor Temp after 4 min 151F

I hate to say it but the kids truck is just ungodly faster than mine. With the setup i have in my T4 its slower than just a 27t stock brushed. I tried uping the pinion and got to a 34. It is "faster" than the 23 pinion and still doesn't get over 120F even after 8 minutes but the brushed still blows me out of the water speed wise. Anything higher than the 34 and the ESC stutters and shuts off.

Any hints as to where i should go to with the brushless motor?

~Corey

You have to gear up a lot. I have somewhere around a 25/78 using a 13.5 brushless. The 15.5 will be a bit slower then the 19T, a 13.5 is about equal to a 19T.

i run the same setup on my t4 25/78 and the thing flies it keeps up with mod truck lap times

Just ran a main today with 13.5 78/28 gearing. LRP TC on pro 5. 7 min main and motor was 122*

swap spur gears with him!
just not right when our kids
beat us!