For sure the 7xl has higher torque. Be careful if you over cell these motors. If it draws too much power, it will damage your speed controller. The 8L could handle some high voltage for a bit, but it is far from ideal. If you want the power of 20 cells, get a motor that can handle it(as sguee mentioned, the 8xl or even better, the 9xl).
man, i wish there's a mini transformer that i could plug in there so it will convert the 20 cell voltage to 14 cell but runs longer because it's 20. kinda like the volume units on radios.
Possible.. just limit your esc on the transmitter. that is the best way to do so..
but that motor is way too hot for 20 cells..!! it will reach a very un-efficient state, and it will get burned or the controller will die because of the high current it takes.
i've just removed the 8L and installed the 7XL and added a taller pinion. it seems to accelerate faster, and when i rev it up at the work bench the chassis seems to hum at 14 cells :)
can't wait for my additional cells to arrive
it also took me 2 hours to connect new deans to the motor :( . is there a solderless clamp type alternative to deans?