most of the weight is structural in the rear
even though the engine and transmission are mounted up front
the engine and transmission is mostly alloy, other than the gears/clutch and a few other mis things, here's the corner weight of the frs/brz/gt86


with that being said 1511lbs in the front 1212 lbs in the rear
55.49% front and 44.51% rear

rounded to the closest % its 55% and 45%

The weight split discussion has to include wheel base. Ever been on a teeter-totter when you were a kid? Same physics.

The cables certainly can't be heavy enough to offset the battery. And part of the cables will lead onto the rear side of the car.

2760 lbs

55% is 1518 and 45% is 1242.

What happens when you shift a 30+ lb battery from front to rear?

54% is 1490.4 and 46% is 1269.6

The balance is increase to 54/46 instead of 55/45.

How much weight does the cable add? Like less than 5 lbs?

No offense but calculating weight distribution is not this simple. The weight distribution change depends on how far the change is from cog which changes when you move the weight around , the constant is the wheelbase. I am sure someone has an excel spreadsheet on the web that will do it for you if you are this concerned about it.

What does the cog have to do with F/R balance? It doesn't make a bit of sense. A car can have a low cog and still have terrible balance F/R.

You are confusing vertical COG with horizontal COG with COG (x,y, and z) just use wikipedia.

Here is a spreadsheet I found in 15 seconds with google. Didn't review it. If you are interested check it out.

http://www.smithees-racetech.com.au/...worksheet.html

even if the calculations were that simple (they aren't) you're still adding at least 5 lbs with appropriately sized cables and a box to move a small bit of the weight balance to the rear when you could achieve the same effective result by using a 5-7 lb battery up front and also reduce the overall weight of the car.

I guess BMW is retarded for putting a battery in the back then. But then that's one of the reasons BMW cars are known for the 50/50 weight distribution.

Also a 5-7 lb battery doesn't sound like one you would daily drive with.

Not retarded at all. Neither is Mazda for putting the battery in the trunk of my Miata - from the factory. I have no issue when manufacturers do it, just don't see it as being necessary to move the battery to the trunk when it didn't come there from the factory, except for specific applications like when a race car is under required weight for its class and ballast is needed, and a big heavy battery in the trunk could be one way to achieve that.

As to the daily-drivability of a small lightweight AGM or lithium battery? They actually work better on daily driven cars than on cars that are parked and only driven every week or two. Not keeping the small batteries charged up is what kills them, not using them daily. I've been using smaller, lighter batteries in daily driven (and rarely driven autocross/track cars) for 10+ years, from Neons to Mustangs to my Miata.

Another thing that helps with weight distribution is the fact that the hood is aluminum, while the trunk lid isn't.

It can make a huge difference, easily offsetting the weight of the cables. The battery in the car now sits relatively close to the COG, which means it has minimal impact on COG, at least the horizontal component.

If you move it further out on the rear ARM (moving it towards the rear of the car and further from the COG) the same weight gets amplified and move the the COG much more effectively. As someone above mentioned, its just like a see-saw (basic lever).

This is used in experimental aircraft all the time. you can offset a significant portion the weight of a 200lb engine just by putting the battery in end of the tail cone.