I am not aware of any limitations on the chassis of the T4 not accepting a lipo pack. You should be able to run a lipo in a T4. What they probably mean on the forum is that if you buy the RTR, as if comes out of the box... the stock electronics are not setup to run lipos. Meaning... you would need to either upgrade your speed control to one that has a Lipo cutoff built in... or add a lipo cutoff to the stock speedo. If you go with a Kit where you have to add your own electronics then just make sure the speed control you buy has the Lipo cutoff built in. What the lipo cutoff does is shuts the car down once your batteries reach a certain voltage to insure you do not hurt the batteries. Lipos become volitile if they drop below a certain voltage. Hope this helps.