I find it surprising that the the Tekin redline motors are often overlooked. I'm in the midsts of testing my tekin 632 3200kv motor on 4s with the MM in a xxx4. The design of the tekin motors is very similar to that of the Castle motors (rotor size, coreless design, can dimensions) but unlike the castle motors, they are rebuildable and have solder tabs.

So far i've tried 19 and 23 tooth pinion gears, which translate into theoretical speeds of 46 and 54 mph. The battery I am using is a Neuenergy 4s 4100 mah 30C pack - the same battery that I use in my 8ight conversion, in other words, overkill. RTR weight is just under 4 lbs.

With the 19 tooth after 5 minutes of running up and down the street:

Motor: 180F
ESC: 125
Battery: 85

It felt as if the motor topped out very quickly. Motor temps were very surprising high.

With a 23 tooth pinion gear after 5 min;
Motor: 185F
Esc: 130
Battery: 90

Again motor temps were very high. Top end did not seem that much greater, but it was hard to tell since the motor doesn't make any revving sound, and neither does the xxx4 belt.

I'm going to try a 17 tooth pinion gear before increasing the timing from 0 degrees to 10 degrees to see if that improves motor temps. I'm guessing the tekin motors are 4 pole motors since 6 turns seems a bit low for 3200 kv don't you think?

I did speed runs, but not 5 minutes worth. I changed the Trinity N80 in favor of a Novak 5.5R using a 35T pinion and 72T spur. I will also try a 69T spur later. I'm only using 2S lipos and I've been able to reach 50mph+ with the N80, 32T pinion and 72T spur. I have 2 new ESC and a 5.5 motor to try out. Both of this units can be run in sensored or sensoless mode. The Hobbywing ESC can handle 4S lipos, but will the 5.5R motor handles the high RPMs? The rotor is wrapped with Kevlar.

Update: I just got done running the 632 with a 17 tooth pinion. Still 180 on the motor after 5 minutes, esc 140, battery 95. Ambient temperature was 90F vs. 75F during the first two runs. Then I increased the timing to 10 degrees, 175 on the motor, and the same esc and battery temps. Now I know for certain this is not a gearing or a timing issue. I'll ask around the tekin forums on the tekin website i guess.

If the Tekin motor doesn't work out, my other choice for a 4s motor and 50 mph speeds or 2s 7700 equivalent would be a novak style motor of 8.5 to 10.5 turns. My novak hv4.5 is the most efficient motor I've tried. During these summer days, it still reaches about 180 degrees, but thats after a full 12 minute run, pulling a buggy that is twice as heavy geared to go 50.

Those temps are high. I ran my N80 which has a Kv of 7800 with the 35T/72T combo with no heat issue at all. Ambient temps here is also around 90.

I just got one of these. looks good in person. I'll see how it works out.
ez run 4300kv