Building a better targa
08-27-2001, 04:43 PM
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Building a better targa
OK I confess. I love my targa. It really is the best of both worlds, in my opinion. But, lets face it - They leak like a sieve. So, what's best solutions to stopping (or minimizing) leaking? I've seen fiberglass tops... do these help? Different seals? Silcone caulk sealing the top to the car? 
Just curious who's had success w/ what? This would be for a daily driver - so let's not necessarily worry about perfect originality.
Chuck Nilsen
1980 911 Targa
Just curious who's had success w/ what? This would be for a daily driver - so let's not necessarily worry about perfect originality.
Chuck Nilsen
1980 911 Targa
08-27-2001, 06:19 PM
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Where is it leaking? Is the top aligned properly? The only leak my 78Sc Targa has is at the drivers side top/windshield corner. And that's a minor leak - just a drip here and there.
08-27-2001, 08:13 PM
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Chuck-the best advise I can give you is to find a repair shop that KNOWS TARGAS! Drop your car and top off and let 'em go to it. There are several adjustments that can be made in lieu of replacing a bunch of stuff to stop the leaks. Porsche designed the tops to be adjusted for wear on all of the seals, but many folks just don't know how to do it, or where these adjustment points are! The fact is a properly adjusted Targa top with decent seals should not leak. Mine doesn't leak anywhere, even in the heaviest of rain! It took several hours of adjusting this and that to get it that way. Look at it this way-the money you'll spend to get it leak free will be waayyy cheaper than the money it will cost to fix up the rusted door sills, new door pockets, and new carpeting. Your lady passenger will appreciate as well!
08-28-2001, 04:40 PM
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Chuck,
Have to agree with the two other gents here. My 85 Targa does not leak at all... none! The rubber for a Targa is very expensive so do all you can to save it, but if its in good shape and the top is aligned, then it should be watertight.
Strongly agree with R22 that someone who knows Targas is needed to get it right.
Joe
Have to agree with the two other gents here. My 85 Targa does not leak at all... none! The rubber for a Targa is very expensive so do all you can to save it, but if its in good shape and the top is aligned, then it should be watertight.
Strongly agree with R22 that someone who knows Targas is needed to get it right.
Joe
09-01-2001, 06:20 PM
#6
Chuck,
I own a 74 Targa, and have chased this problem for years. I have been able to really correct most of the problems by trial and error, and talking to several very reputable 911 body guys in the area. Here's what I know:
1.Targas have considerably more body flex than the coupes, which over a long period of time can actually alter the fit of a targa roof to the body. My 74 experienced some of this and although the SC bodies were more structural, I would guess that they were not resistent to this problem. A good Porsche body professional should be able to determine any dimensional variences that may have occured.
2. Many times new seals themselves will exascerbate the problem, particularly the seal that goes around the windsheild frame. I was told by several people that these seals typically require a lot of rework (removing material on the non visible sections that seat into the body channels)at the corners where this seal and the front of the Targa side seal mate. Trimming may also be required all along the top seal where it seats in the channel, allowing the top to sit lower on the car. You can determine if trimming is necessary by examining how the front of the targa top mates to the windsheild frame. If it sits above the frame the underside of the seal should be trimmed. Also, if you see light above the vent window frame when inside the car, its gonna leak right there. I had to do a lot of trimming in the corners to get the top down to the proper height.
For reference,I suggest removing the whole seal and putting the top on without it to see how the top fits the body without any of the potential interferences of the seal. This should give you an indication of where seal material needs to be removed.
3. Targa side seals- These can be adjusted outward towards the window glass which can also help (once the top sits down where it needs to)eliminate leaks along the top edge of the glass. (4 phillips head screws located in holes on the underside of the seal. Just sit in the car and look up...you'll see the holes)
4. My last trick to resolve the leak problem in the corners where the vent frame, Targa side seal, and windshield frame seal come together, is to take a piece of 1/8" to 1/4" closed cell, very compressible foam (black or dark grey), place it against the front surface of the Targa side seal, mark and cut out the resulting shape, and glue it to that front surface of the Targa side seal. This is a non visible surface, so you're really just adding some additional compliant material to the mating surface. Test this first without glue. If it makes the top sit up higher again, the foam is too thick.
All of these approaches assume that you have a Targa top in good condition. If this is not true, you'll need to address this before trying all this other stuff.
If all that still doesn't resolve the problem satisfactorily, seek professional help, per the r22tek entry.
Good luck
I own a 74 Targa, and have chased this problem for years. I have been able to really correct most of the problems by trial and error, and talking to several very reputable 911 body guys in the area. Here's what I know:
1.Targas have considerably more body flex than the coupes, which over a long period of time can actually alter the fit of a targa roof to the body. My 74 experienced some of this and although the SC bodies were more structural, I would guess that they were not resistent to this problem. A good Porsche body professional should be able to determine any dimensional variences that may have occured.
2. Many times new seals themselves will exascerbate the problem, particularly the seal that goes around the windsheild frame. I was told by several people that these seals typically require a lot of rework (removing material on the non visible sections that seat into the body channels)at the corners where this seal and the front of the Targa side seal mate. Trimming may also be required all along the top seal where it seats in the channel, allowing the top to sit lower on the car. You can determine if trimming is necessary by examining how the front of the targa top mates to the windsheild frame. If it sits above the frame the underside of the seal should be trimmed. Also, if you see light above the vent window frame when inside the car, its gonna leak right there. I had to do a lot of trimming in the corners to get the top down to the proper height.
For reference,I suggest removing the whole seal and putting the top on without it to see how the top fits the body without any of the potential interferences of the seal. This should give you an indication of where seal material needs to be removed.
3. Targa side seals- These can be adjusted outward towards the window glass which can also help (once the top sits down where it needs to)eliminate leaks along the top edge of the glass. (4 phillips head screws located in holes on the underside of the seal. Just sit in the car and look up...you'll see the holes)
4. My last trick to resolve the leak problem in the corners where the vent frame, Targa side seal, and windshield frame seal come together, is to take a piece of 1/8" to 1/4" closed cell, very compressible foam (black or dark grey), place it against the front surface of the Targa side seal, mark and cut out the resulting shape, and glue it to that front surface of the Targa side seal. This is a non visible surface, so you're really just adding some additional compliant material to the mating surface. Test this first without glue. If it makes the top sit up higher again, the foam is too thick.
All of these approaches assume that you have a Targa top in good condition. If this is not true, you'll need to address this before trying all this other stuff.
If all that still doesn't resolve the problem satisfactorily, seek professional help, per the r22tek entry.
Good luck
09-03-2001, 08:57 PM
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Does anyone know of a decent shop in the southeastern US? Preferably Atlanta, Nashville or Birmingham. I live in Chattanooga and it rains all winter. I adjusted my top some myself, but I'm still getting alot of leakage and wind noise. I also need to get some parts - new rear pins and a new 'catch' for the center in the rear. The front pins and lock mechanisms are still in great shape as is the skin. The headliner is dropping but that's just a matter of some trim adhesive.
