Is there a cooling problem in removing the C2/4 spoiler and replacing it with a duck tail lid? I've owned several 964's in the past decade, and RS Amer and Speedster included. I was looking at 930's but a 1990 c4 caught my eye and i was thinking of turning it into a retro looking RS with duck tail and carrera script on the sides. I was just wondering if there really is a cooling benefit for the automatic spoiler?

 

Well it was installed for a reason. The 3.6 operates hotter than originally intended. Because of this cooling of the engine is quite important. The aerodynamics of the 964 are quite different to the 911RS as well. Merging 1973 ideas with a 1980s product might not be a good idea. I am sure if the ducktail concept worked Porsche may have reintroduced it to the 964 RS. They didn't.
Why not make a replica RS out of the correct year?
Ciao,
Adrian
911C4

 

I'm sure someone on Rennlist has actually done this, with either a 964 or 993. If you have a search in the 'archives', you might turn something up.

 

I am planning on doing the same thing you are. Ducktail, and Carrera scripts.

I got a ducktail on my C2 now. I am evaluating the heat issue. I live here in Texas, so if any heat problem come up, I'll know about it. So far, the weather is only in the low 80s. In 3 months, it'll be 110. We'll see.

anthony,
C2

 

There was a C2 that was turned into and RSR replica (73) in 911 and porsche world i believe (last year?) thier solution was to drill extra holes in the upper part of the ducklid to get more air in - Plus if you take off the undertray you should have an improvement there as well. They went whole hog and replaced the fenders and front deck lid with Pre 74 peices, deleted the side skirts, and replaced the rear bumper to complete the look.
it was very cool imho - modern tech with a retro style

 

If cooling is a problem, would mounting a 2nd Oil Cooler counter-act the loss of the 964's spoiler?

 

In Frere's book, he noted the improvement in airflow through the engine compartment from the ducktail spoiler (as compared to the normal decklid with vent grill), resulting from the air coming down the back window and over the decklid being forced into the engine compartment by the ducktail's upward slant.

Since installing the RS America spoiler on my C2 (seee pics in the link below), I think that my car runs cooler. Once out on the open highway, my car cools down very fast, usually getting to 7:30pm on the temperature gauge, even on 90+ degree days.

As others have noted, make sure you remove the undertray.

Good luck!

 

a retro-look on the C2 or C4 will indeed look great. I am planning on that as well Are you guys planning to leave the Carrera stickers as is or adding a suffix to it, ie 2 or 4 to correcting state your car's type.

 

I am so comforted to know others appreciate that duck tail. It makes a difference. While heading to Costa Mesa in 1984 I was east of Riverside in my touring 73RS, fires in the local hillsides caused temps of 113F.
My RS at 117 mph, it really liked 117, purred at 7:30. And downforce is well, stuck. What's a crosswind?

The RS started the journey in Anna Marie, FL.

But remember, that is a touring version.

I think the compliment to the car's line is only in a ducktail. But I like when it goes up and down!

 

Wow...old thread.

I now have a ducktail on my 993...and I tell you, that thing moves alot of air into the engine. I tied strings to the ducktail grill and put a remove camera in the engine looking at the strings. At speed, you can clearly see the more air as the speed increases past 20mph. And it's not due to the engine fan.

 

axl911: Man, you ARE an empirical scientist!