There are several points:
1. Torque steer (as far as I know) applies to front wheel drive cars only. Since you have the drive shafts going to the same wheels that you are steering, you can feel some pull on the steering wheel, especially when the front wheels are not straight, when you try to accelerate.
This can be minimised by good design, but front suspension design is normally a packaging compromise.
So the engine layout on the 911 has no effect on torque steer.
2. Why is the engine in the back?
When the replacement for the 356 was considered, it seemed natural to continue with the rear engine layout. The company had experience of it.
Having made the decision, perhaps somewhat arbitrarily, they would not have had the resources to change it.
The first cars had handling problems due to poor production practices and control over the suspension geometry. 11kg of cast iron had to put into each corner of the front bumpers.
There was never an idea to change the basic layout.
So why was the 356 rear engined? I don't know, but I guess it copied the Beetle that was also designed by Porsche.
I presume it was a combination of packaging requirements and grip (since tyres were not so good back then).
Race cars are typically rear biased anyway with 65-70% of their weight over the rear.
The 917 Can-Am car with over 1000 bhp was considered to among the best handling, and the 935 which earned 4 World Championship titles for Porsche had 69% rear weight bias. But racing cars also have big wings, which affect the behaviour.
The advantage of rear weight is traction.
Out of a corner the sooner you can get the power down, the quicker you can pull away, and the more of your available power you can apply, the faster you will be.
However, I presume that your peak corner speed should be slightly slower than if mid engined, but by having wider tyres at the rear, you can overcome this.
I think having the rear weight bias may also help to keep the car flatter under braking, since you can setup the rear suspnsion to squat a bit too.
3. Good handling.
This is not so much down to the engine location, IMO.
You have good handling front, mid and rear engined cars, and also bad handling fron, mid and rear engined cars.
I think this is more affected by good basic suspension geomtery design, followed and optimisation of the components, such as spring and damping rates.
You might think it should be straightforward, but many manufacturers still struggle, and much of this area is out sourced to specialist consultant companies.
Having the flat 6 helps with handling though, since you want to keep all weight as low as possible in the chassis.
4. Driver's car.
What does this mean?
Good seating position, good steering/pedal/gearlever position. Without access to the primary controls, you will struggle to control the vehicle.
Quick response to inputs. The throttle should respond quickly to being opened and closed. This is done through minimising the weight of internal engine components and flywheel, keeping the engine under-square to allow free reving, good breathing both on intake and exhaust sides.
This also facilitates heel-and-toe changes and makes driving smoother in general.
The brakes should have good feel, not too much servo assist, with a progressive action and plenty of power.
The clutch should take up smoothly with good bite.
The steering should feed back what is happening to the front wheels. If you cannot tell how much grip you have, it is difficult and dangerous to drive hard. IMO the 996 (can't comment on others) has less castor than other cars, since the self righting effect on the steering wheel is quite small. I don't know if this is true, but it would help to allow you to feel what is happening.
Porsche steering is among the very best and pretty much their trademark feature.
You should get a feel through your backside about what the car is doing. This is probably best by putting the drive in the middle of the car. Look at where the seat is in respect to the wheels.
Basically, it is about how tactile the car is. If you make is smooth and comfortable, then you lose the edge.
It has nothing to do with styling features, like mesh grilles, two exhaust pipes, alloy wheels, red seats, fancy dials, or any of the other things the marketing people come up with.
But making a car that is focussed on the driver, requires some other compromises, which is whay not all cars are drivers cars.
5. If you really want to know about the 911 development, then you could start with Paul Frere's book "Porsche, 911 Story". It is excellent and will probably contain most of what you want to know.
6. If you want to do well in the car business, then I would suggest that you also look at the business aspects besides just the design.
The more rounded you are the better.
All jobs in all industries and affected by commercial constraints. To be aware of the these would help you in any interviews.
Consider why some manufacturers are more successful than others, and what challenges they face.
Migration info. Legacy thread was 101105
