I do not track my car, and have no experience in comparing two cars with these attributes, but would a car with 50/50 or near 50/50 balance handle as well as a mid engine car like the Cayman?
I have driven the new corvette extensively, and I go from the vette to my Cayman S, and mine still feels better in the turns. I can not discribe the difference, but it does not feel as stable.
Why is that, or is it my bias

__________________
Just sold my beautiful CS, now the fun begins as I look for its open top replacement...

Well, I think there must be an inherent advantage to a mid-engined layout, which is why most formula and prototype race cars are built that way. The reason, as I understand it, is because there is less polar inertia in a mid-engined layout, meaning it is easier for the car to rotate around its center axis.

A 50-50 front engine (or rear-engine) layout will still probably handle better than an unbalanced layout. However, the CS may "feel" better than the vette to you for other reasons, e.g. steering weight and feel, less throttle oversteer, etc.

My

__________________
My Blogs
2006 CS Tip (Daily Driver & Part-time Track Toy)
2005 Ford Expedition (to haul the CS)
2006 Lexus RX400h (wifey's)
Gone, but not forgotten: 2002 WRX, 2004 MINI

No, it's not just your bias. 50/50 only describes the ratio of weight from the front axle to the rear. It does not describe the placement of that weight within the chassis, and that makes a big difference.

Let's use the Corvette as an example. It has a great big heavy V-8 engine mounted up front. So how does it achieve a 50/50 weight distribution? By placing the transmission way out back so there is just as much weight on the back wheels as there is on the fronts. But that doesn't mean that a Corvette will turn in like a mid engine car.

In a mid engine car, the engine and transmission are bolted together and placed as close to the middle of the car as possible. This also achieves a very balanced weight ratio, actually 54%R / 46%F in the case of the Cayman.

By placing the bulk of weight closer to the center of the car, the vehicle benefits from a much lower polar moment of inertia. That means it can turn around it's center of gravity much easier and more quickly.

Remember that objects in motion tend to stay in motion and objects at rest tend to stay at rest. This is Newtons first law of motion and it centers around inertia and mass. So, now picture two imaginary chassis'. Both are suspended on a needle in the middle. One has 1,000 lbs of weight right in the middle. The other has 500 lbs between the front wheels and 500 between the rear wheels.

Now imagine trying to rotate the chassis around it's center point where it is balancing on the needle by applying a force to one of the front wheels. The chassis with the weight in the middle will rotate easily because the weight is not really moving, just rotating, and because there is a good amount of leverage between the front wheel, where you are pushing, and the weight that needs to be rotated.

Now imagine the same exercise with the other chassis. You will need to apply much more pressure to the front wheels to get the chassis rotating, and once it starts rotating, it will want to continue rotating (objects in motion.....). This puts a lot more stress on the tires and makes the car feel a lot less eager to turn. Also, the weight between the rear wheels doesn't want to move. Once it is moving around the axis, it wants to keep moving in the same direction. This is what causes oversteer, or the back to slide out, because that weight doesn't want to change course.

In contrast, the mid engine car changes directions very quickly and easily because the mass isn't being asked to move much at all, just to rotate a little around it's center. Much less force is required to accomplish this.

Polar Moment of Inertia:

__________________
Gator Bite
(View My Articles : Blogs : Car : Profile)

Gator Bite

Your knowledge of Physics is a delight to behold............. In the Cayman there are other forces to play............. as we go around corners at speed.

I am a sad fat old 50 something old git............. Driving with my son on the track was fun............. Coaching him from the passenger seat, was great.

Not so much fun, when after I taught him the correct line, and let him loose on his own - he said it was 'much easier to drive without you (Sad Fat Old Git) in the car', it went around cormers, like it was on rails.............

Weight distribution is very particular, any variations make a big difference, even the bodies in the car.............

__________________
Cheers Karel

'Power is Nothing without Control..........'

Now, on the winter roads, it feels very quick and responsive, especially using the throttle around turns.

I may be tempted to think this is due to the low inertia, while other things also contribute - the ideal weight distribution, low CG, nice responsive engine, suspension geometry, tires, steering.

You kind of get the feeling that the car pivots around an imaginary axis going vertically straight through the center of the car, controlled by steering and throttle input, very nice and still very controllable.

__________________
Øyvind Kvålsvoll

2006 Cayman S
1991 928 GT

Gator Bite speak with long wind and straight tongue. The 924/944/968 get their 50/50 balance the same way that the Vettes do; front engine with rear tranny. They're easy to drive fast on track, but don't have the nimble turn-in of the mid-engine cars in tight autocross turns.

When you push it you can feel that axis. Especially if the tires are cold. It's amazing.

__________________
Gator Bite
(View My Articles : Blogs : Car : Profile)

Nice explanation Gator, you made it easy to understand.

Now for your next question..

What is the meaning to life?

PS are you thinking of attending the Roc the Croc event this May?

Yes, I am (thinking about it). Will you be driving down from CT? If so, maybe we can organize a little Porsche convoy...

__________________
Gator Bite
(View My Articles : Blogs : Car : Profile)

Or like the 944/968.

A several times SCCA AX National champ once described his 968 as handling like it was a barbell.

Brian

Nice job, Gator Bite. But the midengine layout has a dark side as well. While it takes more to make it rotate, once it starts rotating it's that much more likely to continue to do so..."a body in motion" has two edges. This explains why front, and even rear engine cars, when they "lose it" they tend to spin in relative slow motion and only once, maybe twice at the most. Whereas a midengine car spins like a top. Midengine wins out at the end of the day because their threshold is much higher, but if you cross that threshold, hang on.

This effect is "old news" in sailboat racing...but then again much of our weight distribution is movable. Up wind when we have strong lateral loading on the sail plan we cram everyone as tightly on the high side rail as possible. Down wind, in contrast, now without lateral loading, we move weight to the outside of both sides of the boat evenly to keep initial stablity up. If we were to move everyone to the center the boat would rock laterally far more, and be slower and more difficult to handle. In the "old days" ship captains would, in the face of a fierce storm, haul cannon balls up into the rigging as high as they could to stablize the ship. It takes a lot more force to move the rig when it's loaded like that. Counter intuitive, but time honored and it saved many a crew.

__________________
2007 Cayman, midnight/tan
2007 Touareg V8, working man's Cayenne, tow vehicle
2007 Mazda3 hatch, ski car and wifey-mobile
1993 BMW 325is Spec E36 race car