Got my ducktail today - need advice on a/c condenser mounting.

ulrichd · 08-05-2006, 10:01 AM

Got my MA Shaw ducktail spoiler today. I have a 78 SC with rear a/c condenser. The side mounting points should be no problem, but the current install on the metal hood has a center bracket (black, shown in pic) that I can't duplicate on the duck.

Anyone have pics on their install or any tips? Thanks in advance.

Ulrich

ulrichd · 08-05-2006, 10:02 AM

Just to be clear - I am asking for advice on mounting the condenser, not the tail itself.

Ulrich

911pcars · 08-05-2006, 10:15 AM

Why can't you mount an L-bracket similar to your photograph? It could be pop-riveted or bolted onto the lid at the mounting surface of the grill. The installed grill should hide the fasteners.

Sherwood

stormmaster · stormmaster's Garage

I just used drilled two small holes and used small diameter nuts, bolts and lock washers on mine....worked like a charm

ulrichd · 08-05-2006, 11:28 AM

Sherwood, the ducktail spoiler is completely hollow on the backside, hence nothing to bolt to.

Don, sent you a PM hoping you could maybe snap a pic of your condenser.
Thanks.

Ulrich

Ed Cavalier · 08-05-2006, 02:39 PM

I had a similar issue when I mounted my Shaw ducktail. I used a piece of 1" wide by 14 gauge (I think, maybe it was 18 ga) steel stock. I bent it so that it would create a place to mount the center bracket with fairly long contact areas with the inside of the ducktail. I attached it to the ducktail by putting a few layers of fiberglass cloth and fiberglass resin over the contact areas. Somewhat hard to describe (obviously!).

I can't take pictures for you; my car was rear-ended a week ago and that part of the ducktail was destroyed.

Regards,
Ed

ulrichd · 08-05-2006, 02:51 PM

Thanks Ed, was your's a green Targa? I remember some accident pics a while back.

Ulrich

nostatic · nostatic's Garage

toss the AC. just a bunch of weight in the wrong part of the car anyway...

911pcars · 08-05-2006, 03:44 PM

"...the ducktail spoiler is completely hollow on the backside, hence nothing to bolt to."

Completely hollow meaning a double wall? That's why I suggested blind rivets (so-called pop-rivets). You only have to access one side to install the rivet and fasten the retaining plate.

Sherwood

Ed Cavalier · 08-06-2006, 06:34 AM

Yes, that was mine. (Still is, until the insurance company and I come to some reasonable agreement.)

Ed

Quote:

Originally posted by ulrichd
Thanks Ed, was your's a green Targa? I remember some accident pics a while back.

Ulrich

Ed Cavalier · 08-06-2006, 06:46 AM

Hi, me again. I just remembered another issue. The condenser doesn't mount as tightly to the ducktail as it does to the stock lid. With mine, there was lots of space for air to bypass the condenser. Significantly reduced AC performance. I tested it by stuffing weatherstripping foam around the condenser. It worked a lot better, but I didn't want to leave the foam in there. I had visions of it working loose and getting sucked into the engine fan. Next thing you know, you're rebuilding your engine because of the cylinders overheating unevenly. In the someday category, I was going to fix that when I had the condenser off for some other reason. Something to think about while you're working-up your install.

I tried the no AC route for a while. Summertime in Houston makes that tough. I found myself taking the other, un-fun, car too often. (Or, maybe, not often enough considering last weekend's incident!)

Regards,
Ed

Esel Mann · 08-06-2006, 07:06 AM

I presume this duck tail to be of fiberglass and with no additional non-fiberglass reinforcement?

For example with a fiberglass Jeep tub, there are additional reinforcements in the way of embedding either metal or wood at the points where the fiberglass needs to withstand addtional stress-strain. It is my understanding that the concept is to spread the stress-strain out over a large area for which the fiberglass can then withstand. However when mounting with bolts for example, directly to fiberglass, each bolt being small area wise, can impart a large stress-strain to a small area of fiberglass.

Notice how the mount you refer to in the deck lid picture is attached right where there is additional deck lid reinforcement. And that is for a metal deck lid!

Has it been confirmed that without proper additional reinforcement, the fiberglass duck tail is capable of providing any form of condenser mount support? Imagine the stress-strain of trying to hold the condenser in place while the car is zinging around town.

Please note, I'm not trying to talk you out of mounting the condenser to the duck tail, my intention is to flag the potential mounting issue because it would be tragic if the fiberglass itself did not stand up with the stress-strain of holding a condenser.

In the past I have mounted what I thought were "light" items directly to fiberglass parts where there was no non-fiberglass reinforcement and well the two which were one quickly became two again.

ulrichd · 08-06-2006, 07:10 AM

Hmmm, I may wind up with a summer tail and a fall/winter tail and keep the steel lid with the condenser and just swap them out. Of course I'll have to have the freon purged before every swap.

Luckily my daily driver is a modified Cooper S so I don't suffer too badly when I am not in the 911.

Good luck with the insurance - I am insured with Leland West.

911pcars · 08-06-2006, 10:27 AM

If there's a potential for structural weakness, you could reinforce the condenser mount areas with longish strips of aluminum to spread the load + add more support brackets. Insulation also comes in the form of high density foam tape, not as likely to crumble and flake off. The material doesn't even have to possess any insulation qualities, just something flexible enough to prevent air from bypassing the condenser (e.g. EPDM or equivalent weatherstripping material).

If it was me, refilling the system with refrigerant each year just to swap deck lids would be enough of a deterrant to not repeat the process too often.

If cool air is a must, keep the A/C. A more radical modification is to mount a condenser up front like the later versions. This moves the weight and mass forward (good) and allows the lightweight ducktail to remain so.

Sherwood

ulrichd · 08-06-2006, 10:33 AM

Well guys, thanks for the replies. I obviously did not do my research on this. After some thought I have put the duck on e-bay and will proudly be a member of the tail-less 911 crowd.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=220014537969&ih=012&sspagename=STRK%3AMESE%3AIT

Ulrich

911pcars · 08-06-2006, 10:49 AM

Ulrich,
I think you gave up too soon. Hope the tail goes to a happier home.

Regards,
Sherwood

ulrichd · 08-06-2006, 11:35 AM

Perhaps you are right. The mounting problems I could deal with, but Ed's comments about reduced a/c performance due to mounting position I could not. Even though this is not my daily driver, here in Texas you need your a/c. It just became a bigger project than I had planned on.

Ulrich

911pcars · 08-06-2006, 12:24 PM

OTOH, a ducktail increases the air pressure around the grill area. That could mean more airflow through the condenser (so would a fan mounted under the condenser when vehicle speed is low). More efficient compressors are also available.

Sherwood

Ed Cavalier · 08-06-2006, 07:59 PM

Whoa! Sorry, I didn't mean to skunk the whole deal! My AC still worked OK, just not as good. If you trial fit the condenser and see where the gaps are, I'm sure that you can mount some weatherstripping, like garage door rubber molding, in a way that keeps most of the air going through the condenser. My comment about living without AC dates back ten years to when I moved to Houston from northern Pennsylvania. I'd taken the AC system out when I lived up there but after a summer in Houston, I put it back-in. Nothing related to the duck tail.

Sorry for the misunderstanding!

Ed

ulrichd · 08-07-2006, 05:52 AM

Ed,
Don't worry that's just part of it. The whole project started to feel a little like putting a square peg in a round hole. I think Rennspeed or Rennsport sells a duck with a ridge down the center that sounds like it would fit my needs more than the MA Shaw. I bought the Shaw because it was said to be the highest quality piece out there-and it was. It's already sold.

Ulrich