Targa Top noise and leaks

stephen burnett · 11-29-2010, 01:51 PM

I love my 1991 911 Carerra 2 but the Targa top challenges my patience. The roaring noise from the top front windshield edge was attacked with a new Porsche seal and is marginally better. I used polyethylene carpet joining strip to bridge the gap between the Targa and the windshield which was marginally useful, but the noise about 65 MPH (don't laugh) is unacceptable. I believe the metal of the Targa frame is rusting underneath allowing it to buckle at the front creating 1/4 inch raised curves ~ I feel they are catching the wind and causing the roaring noise ?

We also have damp seats when it rains. The vinyl top looks in really excellent shape, the front seal is new...the window seals all look in excellent shape so where can the rain be entering ? The seats are not directly under the window seals..can my seemingly excellent top be leaking ?

She is away for the winter snow (except on clear days)
Any advice would be appreciated

Stephen Burnett Kingston Canada

kach22i · kach22i's Garage

Porsche 911 Targa & Cabriolet Parts - Page 4

JM-PRO-T1

Quote:

Targa Hard Top Shell (Fiberglass) - replaces soft Top, requires original frame. Fits 911 1974-89. [More Info]
$575.45

Targa Top Fiberglass Shell
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=JM-PRO-T1&catalog_description=Targa%20Hard%20Top%20Shell%20% 28Fiberglass%29%20-%20replaces%20soft%20Top%2C%20requires%20original% 20frame.%20Fits%20911%201974-89.

Quote:

This fiberglass hard top attaches to your existing Targa frame and utilizes the stock latches and seals. The black gel-coat finish is ready for paint or covering with an OEM type vinyl. The inside is ready for a glue-in headliner – no sewing required. The top is fabricated with hand-laid fiberglass in a mold fabricated from an original factory hard top. The installation is easy and takes advantage of existing screw holes in the frame and is rigidly attached when properly installed. Why spend money on a new soft top that needs to be replaced again and again? No more sags and wrinkles – the perfect curve of the hard top will always reflect the original contour the Porsche designers intended. Download installation instructions here (requires Adobe Acrobat Reader).
Kit Parts:

turbochad · 11-29-2010, 04:47 PM

Stephen,
It is likely that your top has never been properly rebuilt and the car is over 20 years old at this point. While the cover can look fine on the outside, the inner structure of the top is likely bad. I had my top rebuilt by Dave Brown in Boulder and now no more noise and no leaks. You should contact Dave Brown (303) 499-0110 or Cars Inc (Vintage Porsche Parts and Targa Tops for Porsche). Either of them will help you fix your problem so you can enjoy your Targa the way it was meant to be enjoyed.
Cheers,
Chad

walt · walt's Garage

Stephen:
Did you check the 4 retaining clips that hold the vinyl top to the targa lock bar in the front. If these are not correctly adjusted, the top will lift from the frame and cause wind noise.

Drisump · Drisump's Garage

Stephen, I assume that either you've been in another Targa at speed or yours is so outrageous, that you've sent this post. Targa's are not as quiet as coupes, but are surprisingly quiet compared to "top off" motoring. I've not heard of any home-made mods that are effective in quieting down a noisy top. That being said, there are clips available from "another supplier" that, according to the claims, reduce wind noise. I'm inclined to agree with Turbochad that the cosmetics of the top was redone at some point but done by someone not familiar with the "art" of Targa top rebuilding. Are you sure that the new seal was the correct one and it was applied properly? I'm thinking that if your seats are wet, the water has to be dropping on the dash and splashing on the seats....no? Maybe you should consider sending the top out this winter, and from what I've seen, Dave Brown is an excellent choice.

cbush · 11-30-2010, 06:56 AM

Quote:

Originally Posted by walt

Stephen:
Did you check the 4 retaining clips that hold the vinyl top to the targa lock bar in the front. If these are not correctly adjusted, the top will lift from the frame and cause wind noise.

+1 there are two likely causes of a "roaring noise" and that is if the top in not seated in the front clips and the top is raised, or if something is pushing up the front, causing the same issue.

They really are pretty quiet when adjusted properly and in good shape.

nesslar · 08:12 AM

"...the front seal is new..." Truth might be that you don't really have a correct seal. It could also very well be that the inner structure of the whole top is not holding up, causing the "warping" at speed at the front. The front of the top should be rigid enough to not move at all once in place. The clips are key as stated of course. You might want to contact Dan Petchel at carsinc.com or search his name here. Maybe you can find his phone number (New Jersey I believe). He has (or had) the proper seal for 911s. He could also rebuild your's for a price (I don't recall it being too outrageous, if at all). My was bought from him, (totally rebuilt) and my car is very quiet! I need to very slightly adjust the side seals above the window glass on each side and it will be even better no doubt.

tcar · 11-30-2010, 08:28 AM

Dave Brown rebuilt the targa top on my car (see TurboChad's post) several years ago.

My targa is almost as quiet as a coupe doing 'the ton' over Vail pass.

A common issue is the front seal, the new ones are too thick for the earlier (85 and earlier)tops.

stephen burnett · 11-30-2010, 11:52 AM

Many thanks to all of you chaps for good solid advice ~ often based on your own experiences. One item I may not have emphasized enough is that the front of my top is slightly bucked like this ~~~~~ and presents a few tiny 1/4 inch high-spots for the wind to catch. Might this be the cause of the roaring wind noise. If so then I can have a local shop rebuild the frame and fair the leading edge to the windshield. Thanks again
Stephen

craigyirush · 11-30-2010, 12:01 PM

Don't mean to hijack, but a few of you have indicated that your rebuilt top is really quiet.

I know this is a hard thing to quantify, but how quiet? No wind noise? Some wind noise?

Mine is old and getting really annoying on the freeway.

nesslar · 11-30-2010, 12:48 PM

I think it's a matter of a structurally solid top and all good seals, all properly fitted and adjusted (front and side seals). I have an '86, and it isn't annoying at all at speed; easy conversation, listening to the stereo, whatever. If your top is annoying it needs work. FWIW, I don't find my Targa on the freeway annoying even with the top OFF. The noise you guys refer to can only be fixed with some work (repair/rebuild). I'm guessing all the aforementioned tops are able to clamp/latch into place OK; so it's a matter of getting new and/or proper rubber all around it/on it, and/or making sure the top's inner metal structural parts (quite a few in there) are solid and firmly in place. I'm thinking that good structure is lacking, especially with Stephen's and your's (craigyirush). Again FWIW, my top, not folded, feels like it can't be folded when I lift it off; very rigid and feels like it's a solid chunk of roof.
Just noticed that my number of posts reads backwards 9...911!

RSTarga · 11-30-2010, 01:38 PM

I would really not get your top rebuilt locally. There are very few who can do this properly. I highly recommend Dan Pechtel at Vintage Porsche Parts and Targa Tops for Porsche Why do it twice. Your 91 should be very quiet in comparison to our older cars as they completely redid the front and the latching mechanism. If you have any gaps at the front you catch wind and generate alot of wind noise.

nesslar · 11-30-2010, 02:18 PM

Right on.......

No affiliation, I just know from 1st hand experience he is great.

Drisump · Drisump's Garage

I agree with the others that say "go to an expert" for Targa tops..... it is an art that few have mastered. I didn't need a rebuild, only a recovering. Before I knew better, I took it to a respected local shop, the job ended up OK, but by no means comparable to the work of the specialists. Cheers

vulcan300 · 11-30-2010, 07:04 PM

A rebuilt top is definitely the way to go. Dan P at CarsInc in NJ has had proper front seals made, although since you have a newer P Car the current OEM seal may be correct. Dan would be the best person to ask. One thing I'll mention is that when I had my top rebuilt I initially did an exchange and the top I got was insanely loud on the highway above 50 Mph. It was like having a jet engine on my roof. I sent it back and got the rebuilt version of my original top returned to me and it was nice and quiet at speed on the highway. If the top is ill fitting, the front end catches the wind, or the bonding between the layers has gone bad from age you'll get plenty of noise. Have your top rebuilt by Dan or Dave and you'll be happy with the results.

turbochad · 11-30-2010, 08:23 PM

You need a specially made jig, imported materials, unavailable parts, and a ton of hard earned knowledge to properly rebuild these tops. Trust me when I and others tell you to send it to one of the two individuals recommended here. I know Dave has a loaner top that you can use while he rebuilds your top.

As a note, Dave measures your car diagonally from the targa bar pins to the opposite side windshield frame pin receiver to set up his jig for your top. Every car is different and not all cars are square. Over the life of the car the top webbing degrades and the chassis moves and relaxes so that the top just doesn't fit as tight as when it was new. When you get it back it fits TIGHT.