Fastback vs. Flying Buttresses

[NewyorkKopter]

Hey, It's been awhile, but any who

So fastbacks vs. flying buttresses. What are the advantages/disadvantages of each? (Talking about performance)

[MagicRat]

Originally Posted by NewyorkKopter

flying buttresses.

This look was popular in the late 1960's, particularly in the Dodge Charger. Back then, it was called the 'tunnel back'.
This was done for styling only and had no performance advantage.
All other factors being equal, the fastback design was more aerodynamically efficient. I believe the few tunnel-back cars designed later received flush fastback-esque glass to make them more competitive on the NASCAR circuit.

Some other cars, particularly some rear-engined cars (ie Porsche 914) used a something like a tunnel back design to support the roof but also provide decent engine access.

[NewyorkKopter]

so basically the only use flying buttresses have are for styling and or practicality with no benefit toward performance?

[MagicRat]

Originally Posted by NewyorkKopter

so basically the only use flying buttresses have are for styling and or practicality with no benefit toward performance?

Yes.

Not only is there no performance benefit to a 'flying buttress design, it may actually be a slight performance hindrance.

One of the most important things in aerodynamics is the reattachment of airflow after it has passed over the vehicles. Aerodynamically efficient designs have long sloping tails, (like a teardrop or raindrop shape) which allow the air to pass over the tail of vehicle with a minimum of turbulence.... look at the rear of a modern passenger plane as an example.

A flying buttress design creates a nasty little area of turbulence and low pressure that creates extra drag on the vehicle.

Another example....... the 1978 Corvette received a fastback style glass hatch in place of the old buttress design specifically to improve aerodynamic efficiency (and to increase cargo space access)

[NewyorkKopter]

oh trueeee. So even a sloping rear window with slight flying buttresses would still be a hindrance to performance, right? Because the air the wouldn't be able to flow as smoothly, right?

[MagicRat]

Although Ferraris and tremendously functional, they are highly styled and often have body features that increase drag.
However, realistically, they have more than enough power and speed to compensate for such deficiencies in the hands of a typical owner.

For example, I suspect few owners are going to complain or notice if the C-pillar design shaves 5 mph off their top speed.

[NewyorkKopter]

haha yea. Oh dude you read it before i "finalized" the post. hehe np all good.

So you bring up an interesting point. I thought Ferrari did their cars according to form following function as much as possible.

But anyways I'm curious, what are some body features that Ferrari uses that hinder performance?

[MagicRat]

Originally Posted by NewyorkKopter

But anyways I'm curious, what are some body features that Ferrari uses that hinder performance?

At the risk of oversimplifying what is a very complex engineering issue...

Excessive air scoops, grilles and ducts, side strakes (a la Testarossa), big wings, sharp body creases, body recesses, excessive fender flares, non-flush mount lights, pop-up lights, excessive body width, and basically anything that takes away from a smooth 'teardrop' shape.
Also, wheels are another area. More modern Ferrari wheels have very large gaps between the spokes. This causes disruption in airflow. Brakes can still be vented properly even if the rims are made to be a mostly smooth, efficient disc. IMHO the gaps are there mostly to show-off the fancy decorated disc brake assemblies.

Also, there are many comfort and convenience features that add weight and sap power, like power accessories, air cond. etc.

If all Ferraris were truly form- follows -function, they would all end up looking pretty much the same (and would be pretty boring) as well as being cramped and uncomfortable.

[NewyorkKopter]

Originally Posted by MagicRat

If all Ferraris were truly form- follows -function, they would all end up looking pretty much the same (and would be pretty boring) as well as being cramped and uncomfortable.

Good point. Thanks!!!