JackOlsen

At the track, I run a big 3.8RS rear decklid with extensions and a 50-odd inch wing. It does a great job at reducing my car's high-speed lift, but I'll make no secret of the fact that I don't like the way it looks.

So, I'd like to replace it with something else. The problem is, none of the pre-1989 tails can match its capabilities.

Oddly, modern 996's and 997's have adopted something close to the ducktail in back, and the newer track models add a simple extension and wing. I know the new cars have totally different aerodynamic footprints, but seeing the recent cars has got me thinking about adding something similar to a ducktail.

Here's what I mean about the newer cars:







Now, my gut reaction to the new configuration would be that the lower element would seem to put a higher-pressure zone right where the upper element is relying on lower pressure -- i.e., the 'ducktail' is pushing air up toward the low-pressure underside of the elevated wing. Obviously, Porsche wouldn't be doing this if my gut-driven analysis were correct. Can anyone fill me in on what the air is doing with the two elements on the 996/997 cars?

And also, does anyone have input on the viability of adding a wing in a similar way to an early car?

Imagine a set of curved uprights and an elevated wing being added to a silhouette like this:



Would I want the wing forward of the ducktail, or behind it, or right above it?

I know I'll be giving up some of the cooling advantages of the 3.8RS decklid, and I know it still won't look period-correct. But at least it won't be as huge.

I assume the higher the wing is elevated, the better (for the sake of clean airflow) -- but then, my assumptions are based on precious little real knowledge.

Any input?

Geo

What about a 935 wing?

Geo

A rear view....

earlyapex

Jack,

I don't think the aerodynamics of this design is adverse. The 996 GT3 tail base is also used to force air into the engine and get a few extra hp. Dual element wings are very common in open wheeled cars so the two wings should work together to increase total downforce. GT Racing has their version of the 996 GT3 tail base and uprights for the 911. The package would look much less bulky than the 3.8L style wings commonly used. I met someone from SoCal with an early car using the GT Racing base and a set of custom short uprights for less drag and better straight line speeds.

http://www.gt-racing.com/catalog/default.htm

Cory M

Looks like GT has exactly what you're after, it isn't cheap but maybe you can use your existing airfoil.