Originally Posted by gigaplex

An HV pack won't hold voltage any longer than a regular pack when charged to 8.4V. Our sanctioning body limits charging to 8.4V at 10A. I think I use somewhere in the ballpark of 2500 during a run, though it has been a while since I've checked (yay COVID). I do have some HV packs but there's no advantage to them with our rules.

Using a shorter battery (mounted at the rear of the car) and swapping the servo to the other side of the chassis will only move the CG towards the rear of the car, as it's removing battery weight from the front of the car. The servo stays in the same plane, and my ESC is already mounted in front of the motor. The only advantage I'd gain is mounting the lightweight receiver down low instead of on top of the servo. I've not seen any tungsten weights that would fit in the centreline of my car, since there's very little space between the servo mount and the motor mount. Certainly not 50+g worth, and not at a reasonable price.

Edit: I quoted your original post before your edits. I'm the president of my club, I'm not going to intentionally run underweight just because I was too lazy to tech everyone else. That would set a bad example. And I've only got about 20g of counterweight on the opposite side of the battery. Without that counterweight, I'm 15g underweight. If I put my shorty in, I need about 100g on the battery side instead to balance it. If I move the servo to the battery side, I still need weight on the battery side and I have to move the battery to the rear of the chassis, moving the bias towards the rear. And then I'd need to add a bunch more weight to be legal. I'm faster when I run with this larger battery configuration and less added weights.