Targa top inflates at speed. Any fixes?
 

This top was rebuilt by the previous owner. It looks great, but seems to blow up like a balloon on the highway. Any suggestions?

http://forums.pelicanparts.com/uploads/topballoon.jpg

A coupe :rolleyes:

1. an additional seal can be used between the windshield frame seal and windshield frame. it sits at the edge of the targa top when the roof is in place. the part # is 911.799.565.25. unfortunately, i don't know if this part is still available.

2. you can adjust the tension of the top by approx 15 mm on each side. to do this, remove the lateral targa seal and rain gutter. then undo the cover, tension it (but don't over tension it), and bond it back in place. reinstall the gutter and seal. btw - try doing it on one side first to see if you get adequate tension.

3. another fix is to place your top upside down on a soft surface. using a rubber mallet, carefully hammer out some of the creases at the front of your top. when you do this, it helps to raise the opposite end 40 mm to slightly bend down the front edge as you hammer.

i got this info from porsche...

good luck.

Thanks for the info.

1. I'll check on the seal, but I can't decide if air is getting under the top or if it's a low pressure lift.

2. When you say "bond" back in place. Is that using an adhesive. Sorry, but I've never had my top apart so I'm not familiar with the internal workings.

3. I'll consider this if the other two suggestions fall short!

I should have asked some of the others on our AZ tour at what speed it was coming up.

yes, you'll need to use adhesive to put the cover back in place.

btw - you should check out the pelican parts targa top articles to learn more the inner workings of the top.

http://www.pelicanparts.com/techarticles/911_targa_top_recondition/911_targa_top_recondition.htm

http://www.pelicanparts.com/techarticles/911_targa_top_recover/911_targa_top_recover.htm

Holy cow!
For almost five years I've been trying to think of something I could do to make my top a little quieter!
What you said about bending the leading edge down was sheer genius! I just went out in the garage and used a mallet to "convince" my top that the leading edge actually wants to sit lower! It definately LOOKS better, but the real test will come in the morning when I head off to work!

You guys can expect a full report in the morning...
:)

well leland, maybe this will change your mind about carrera owners. we're not all bad.

btw - i got the info from a porsche technical bulletin titled, "911 Sealing Body - Coupe, Targa, Cabriolet" WKD 497 221. it has lots of great info...

Lee,

The above fixes work ONLY on a Carrera! Do not attempt to use a later model cure on your SC! It would only revolt and then you would be more like us, driving a 911 mod'ed like a Carrera... :)

Joe

Could we have a little more detail on the mallet technique? I got my top reconditioned. It fits fine across the back and in the middle of the front, flush with the top of the windshield, but on each side of the front the top sits up a little. When you look from the front of the car it's obvious.

sorry, the manual doesn't say more on the subject. i did, however, make a typo. the opposite end should be lifted by 400 mm, not 40 mm as i wrote above. the idea is to carefully hammer the edge to match the contours of the roof line.

if you can't get rid of the wrinkles/bulges this way, the other option is to retension the top. however, if your top is sealed well, with no excess wind noise, it's probably best to leave it as is.

David:

Did you get new front pins when your top was rebuilt? It could be the new pins are not seating in their respective holes properly. OTOH it is possible that whomever rebuilt your top did not reset the aluminium plates correctly. There are three and it is very obvious when the outside set do not sit correctly.


Targa87: Just so I understand on the hammer procedure, the top is upside down, lifted at the back end, and the rubber hammer blows are being put to the area just back of the lip of the top, maybe 2"? This would curve the alum. plate a bit so that you have a natural downward bend at the front.

Did I get that right?

John

I markedly reduced this same problem by following Dave the Targa guys recommendation to cut about 1/8" off the bottom of the new front Targa seal I installed. Apparently the original seal for 85 and earlier targas in NLA and the new Porsche seal is a bit too high. Mine "looked" OK at rest but with driving and some positive air flow into the cabin it sure popped up a bit . If your PO replaced the seal this may be of help to you.

jdub,

yes, that's basically what i did. it worked well in some spots, and in others it didn't do all that much. don't overdo the hammering though (small changes in one spot may cause problems somewhere else - so in this case, less is more) and be careful on the parts where the top folds (those spots may be brittle from age). it would also help to warm up the top first; a rubber hammer and an ice cold top don't make good friends.

alex

If it doesn't lay down like it should just USE A BIGGER HAMMER!http://www.pelicanparts.com/support/smileys/smash.gif :D

Lee,

My top did the same thing. Whats happening is it's stretching. I picked up some foil insulation and inserted it between the canvas top and the frame. It makes it harder to get the ends down and with much difficulty I managed to do so with the exception of one corner which I plan on tackling again. You have got to take up the slack in the material

The other thing you might try is to pull both ends down tighter. That means the front seam and rear seam will be tucked down more which will also take up the slack.

Steve

"A Porsche does more then just go fast in a straight line"

ive found that if you take a syringe 21 gague will do and inject a strong adhesive at soem spots you can avoid having to tair things apart, marine adhesive is pretty freaking strong also