4-cells is a terrible idea. If anything we should go to 8 or 10 cells and run 4/5 sub c cells with higher turn motors. The higher the voltage, the lower the current needed to achieve the same power. Since losses are proportional to the current squared, it doesn't make any sense to to lower in voltage and go higher in current. If we run more cells and draw less current, we don't need as big of cells to get the job done. There are several cells on the market that would work with this, the GP2200, the KAN 2000's, the Sanyo cp1700 and cp1300. All of which are 4/5 sub-c or smaller. Heck if you take this to an extreme, run gp1100's like the mini-t and rc18t. Take for instance the mamba brushless system, 4-16 cells and 25A continuous. Running 12 cells and 25 amps (assuming 1.1V per cell) is 330 Watts of power. The cells can't suport this forever, but even at 10A you still have 132 Watts of power. Brushless being 80% efficient or better, you would have 105W comming out of a tiny little motor. This may not work in a 1/10th scale car, but other brushless systems would at 1.10th scale. so could brushed systems. I know companies like novak and gm don't make good controllers anymore (more than 6 cells), but that is a very small reality in the rc world. To add to the pain, if you go down in voltage, brushed motors will be even less efficient than they currently are (<50%)!! I^2 * R is the problem. Lets use our brains and take this hobby in a better direction. Just my $.02