andrew911

If they take your tray off, keep the tray and any mounting hardware. If not, it will be gone, and you never know- the next buyer may want it and ding the purchase price if it's missing. I know I would want everything as it left the factory as much as possible on a used Porsche...

By the way, I kept mine on.

pat056

Off

Southampton76

off

TR6

I agree there is no harm hanging on to the undertray if you have room to store it. But how many 964's have the original radios (either installed or packed away in a box)?

cobalt

I keep every piece I remove and have all the original parts to all my cars. After I ripped them off the car that is.

If you have no oil leaks the cover will do nothing to prevent road debris from getting up in there if anything I found it raps more junk and can become a fire hazard with leaves and other items resting on it trapped by oil and drippings.

elbeee964

Or 16" wheels?... D90's?... Flags?...

.......Phone dials? [involuntary shiver] (or did those disco mirror-ball wheels die exclusively on the 3.2's?)

Anatol

On, on and on (C2, RS and C2).

Well, here in Germany you can attain top speed for hours (like going from Zurich to Stuttgart in 90min). So, aerodynamics are a factor.

Heat? The cars are oil cooled and my oil stays cool with a second oil cooler...

cobalt

If aerodynamics are the primary reason for these (I am not so convinced how much it helps) Why didn't Porsche install them on the turbos with the higher top speed? Or where they fast enough without the additional aids? My turbo exceeds the top speed of my C2 by a fair amount and rather quickly too, If anything makes them unstable it is the drag off the rear fenders, but it is more stable at high speeds then my C2.

Anatol

Aerodynamic concepts of widebody and narrowbody cars differ. On the Turbo, the rear wing helps compensate lift better than the smaller wing on the C2. And with its big cheeks, Turbos always have high drag figures. To have superior speed, they need lots of power. And the hot turbo prevents the use of an undertray.

The C2/RS follows a more delicate path, with reduced drag through narrow body and undertray. Hence, a C2 with 290 bhp is as fast as a Turbo 3.6 (top speed).

It is interesting to read Paul Frere in "Porsche 911 Story" about the aerodynamic efficency of the 964 vs. 993 etc.

TR6

I don't think there is any question that, in general, a full under pan on any car will improve the aerodynamics at speed. This was demonstrated back in 1952 when Ken Richardson drove the Triumph TR2 at top speed on the Jabeke Highway in Belgium. They did multiple runs: with the under pan and without. The TR2 achieved a higher top speed with a full body under pan (hit 120 mph). If I remember correctly, back in 1961, Jaguar did the same thing with the XKE to (barely) achieve the now famous 155 mph mark. Without an underpan, the XKE was a few mph shy. My memory of Jag lore is a little hazy though, so double check that fact for yourself.

But, in practical terms, whether my car can achieve, say, 164 mph vs. 160 mph is somewhat irrelvant to me since I'm unlikely to ever see either of those speeds anyway. So I'll trade those aerodynamics for ease of maintence, etc, without the under tray.

Bull

OFF.....because the Factory never put one on!

cobalt

I might have misread but I thought someone mentioned stability through aerodynamics we are talking top speed and not stability. That makes more sense.

Anatol,

You feel a C2 with undertray and 290 hp can achieve in excess of 180 mph top speed?

Do the newer cars have this undertray? I thought Porsche eliminated it after the 993?

newsboy

If you drive it in the winter, ON.

Chimera

Off

Doc

race911

Exactly! And how many other factory 964 chassis competition cars had them?

Anyway, you want squirmy........try an old short wheelbase car wrung out to whatever top speed it could muster with a 2.7S engine in it. Yeah, young and stupid.......

Oh, and "off" for all of mine for ease of maintenance.