Ruairidh

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Randal:
<strong>Anyone have any experince running the 964s without the bottom engine pan?

randal</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Yes, my Texas car has always run without it (even during its stay in Michigan), no issues as far as I'm concerned.

Peter H

Randal, yes, I have had my car for about 2 years and have had the pan removed for the last year. It does seem to run slightly cooler, but not much, going by the temp guage. It's interesting though, my car seems to get hotter on a mild day (say 25C/77F) in extended stop/start traffic than it does on a very hot day (say 40C/104F)in flowing traffic or on the open road. That holds with or without the pan.

Regarding the aerodynamics, I have had it up over 210 kph (~130 mph) on the track since the pan was removed and it was rock steady.

andrew911

Peter- the way your temp guage is reading makes sense- that has been the way the guage reacted in my '78 sc, '87 carrera, and now my 964. As the car is moving at highway speeds the temperature of the oil drops because (1) air comes from the front spoiler and flows back to the motor (yes, even those of us that still have all the belly pans on), (2) the wing moves up to create more aerodynamic downforce, but also increases the size of the rear vent/opening allowing more heat to escape the engine compartment, (3) the external oil cooler cools the oil better with constant airflow, and (4) the fan pushes much more air over the cylinder barrels at 3,000+ rpm vs. idle speeds when sitting in traffic.

You may not notice any seat of the pants difference with or without the belly pan over the motor, and may not notice much difference in the temperatures- porsche has it there because they are perfectionests I would say .

Here is an excerpt from John's 964 web page, an excellent page by the way,(http://www.porsche964.co.uk) from an article he has posted on there. The article originally appeared in European Car magazine. It talks about the great lengths Porsche went through to make the 964 more aerodynamic, including a discussion on the flat underside of the car:

Aerodynamic Efficiency
While the styling changes that set the Carrera 4 apart from its 911 heritage are subtle at best (new bumpers and an integral rear wing hardly qualify as revolutionary), Porsche's most advanced design improvements go unseen; unless, of course, you slide underneath the car and look up. What you'll see is. . . nothing.

The most important part of aerodynamics is minimizing resistance to the flow of air over the body of the car. But, equally important, though seldom addressed, is the resistance to airflow from beneath. Thus, the Carrera 4 is the first road-going Porsche to offer a full-length belly pan, the underside almost totally enclosed by plastic and metal panels. The engine itself is encapsulated by a full pan, bordered on either side by molded plastic panels. Also fully enclosed is the exhaust system. Except for the wheels and outer perimeter of the suspension, every thing is concealed. While reducing exposed area, the panels also retain heat, so the functional air intakes in the front of the bumper are used to direct air through the sealed undercarriage to assist in cooling the transmission, engine and anti-lock brake system.

In their overall application, the undercarriage panels serve several purposes: Foremost are the obvious aerodynamic gains provided by a smooth unobstructed surface--in theory, a race car-proven ground effects design; moreover, the enclosure was designed to reduce the level of noise emanating from the engine compartment in compliance with European regulations, making the Carrera 4 noticeably quieter than previous 911s. In turn, this also reduces exterior road noise entering the passenger compartment, providing an uncommonly quiet interior environment. Not too quiet, of course: You still get a proper mixture of engine, transmission and exhaust sound, but fewer bumps and thumps invade from the pavement below.

With the Carrera 4 body design, Porsche has managed to establish a new generation of cars with enhanced aerodynamics and reduced interior decibel levels, while at the same time avoiding an attack on holy 911 standards. A compromise? Perhaps. But how else can the old and the new exist together in harmony?

Randal

From all I have read in other threads I think I would rather have less heat and not be as super aerodynamic
I was also told that the heat will hurt the top end of the motor
So I'll keep the pan off
Thanks guys for the great info

regards

randal

Christer

Randal

I also run without a belly pan but due to the fact that it no longer fits due to my current exhaust system rather than any feeling on my part that it is better to do so or not. No problems with hi-speed stability and no change to actual oil temp in the engine (well, you wouldn't expect that anyway).

Atlmike

Randal,

Who is doing your wrenching for you? I live in Alpharetta and hope to join the P-Car club in the next year to year and a half. I'm always interested in hearing reviews of local mechanics so I'll have a good pool to choose from when it's time for a PPI and maintenance.

Mike

Randal

Hi Christer

I do some of the work ,but for stuff I can't\dont wanna do
I use Franz Blam racing ltd.
I have had my Porsches there for about 20 years now, they are one of the Best in the country on Porsche cars
They have been in Tucker same location for over 20 years now

Randal