I see some track race cars, especially old ones made in the 1960s-70s, are designed with the heavy components of the car sitting between the rear wheels. In fact, some of old rear-/mid-engine cars use transmissions where the differential goes between gearbox and the engine to provide even closer engine placement to the center of rear axle.
What are the advantages of this layout, when the center of gravity is placed over the center of the rear axle?
From my understanding front wheel drive provides stability, so if the engine is placed at the rear axle does it providing better grip?
I see some modern track vehicles have the engine placed even farther back. Does this mean the older configuration is not as effective as they thought back in old days?
I learned that a car with instantaneous center of rotation goes further with slip from the rear wheels. Is this reason why they placed the engine at the geometric center of car in modern track cars?
Do cars with smaller engines perform better with the engines placed over the rear axle, or is this an illusion of longer wheelbases and smaller engines in modern cars?