brushed motor with LiFe.

[fearo]

Hi all, I've been reading the forum for a while but never posted. I just got into this wonderful hobby. I just got done building my first car, an Ansmann Mad Rat, and it was a learning experience to say the least .

Anyway, like everyone in this hobby, I'm thinking of upgrading some parts.
I'm pretty much set on getting som lifepo batteries, because of their safety/power combo.

i'm also thinking of changing out the motor, as the 28T motor the madrat comes with, isn't exactly a rocketship. However, I have absolutely zero clue of what these lower voltage lifepo's (6,6v) will do with a brushed motor. Should I be on the lookout for a certain type of motor that handles lower voltages well? avoid this combo alltogether? Change gearing?

I've been looking at the Team Orion Method 21T. Good choice? Mind you that my ESC can only handle up to 20T (it's an mtroniks RV20), and also I'm not planning on going brushless just yet, nor would I want to send a lot of money (max 40 euros) on a brushed motor. thanks