"Fun" with new OEM Headliner bows

[DJN]

Hi All,

I've just started test fitting new OEM Porsche headliner tension wires/bows for my headliner install... And have run into problems.

First a little background, my car is a 1972 911T non-sunroof coupe and it has not had a headliner in it for 20 years or more, as it was set up as race car. So I have purchased the correct part numbers for the tension wires (and rubber end covers) which are also coded by color: two greens, a white, and a yellow.

It seems however that none of the headliner wires fit into their place properly… that is, they are too long and end up bowing forward or backwards because of the excess. They should fit in perfectly straight, I would think, and follow/touch the contour of the inner roof line in order for the headliner seams to be straight.

Should I straighten the end hooks, trim and re-bend each side to get a symmetrical fit? Is this something anyone has had experience with ? It seems easy enough, other than being a PITA....just want some feedback before I begin.

Thanks for your help/comments,
Doug N

[jimtweet]

It sounds like your missing the little rubber ends on the bows. I just went through this.

[DJN]

Hi jimtweet,

I have the rubber ends.....

I can't get the bows to fit in place with or without them....with the rubber ends on, they bow even more, as they (the bows) are effectively then "longer".

My bows won't fit because of excess wire.

Cheers
Doug N

[mickey356]

I just did my headliner this summer.
I'm assuming you have them in order (all I remember now is the two that are the same go toward the rear). And I'm assuming you actually have them in the headliner, correct? Are these the original bows? No mods done to mounting points?

[joefrantz]

Don't modify the bows. It is normal for them to snap forward or backward from their normal arched position when they are unsupported by the fore/aft tension of the stretched headliner. Even when they are in the headliner pockets, they will want to flop around until there is tension on the headliner.

Given your cars history, it is probably also missing the foam pad that is glued to the roof panel under the headliner. I'm not sure what the exact purpose of the pad is -- probably sound insulation -- but it provides the added benefit of 'bedding' the bows, and holding them in position while the headliner is stretched and glued.

The pad in my 73 was old style yellow foam with a jute backing. the jute side was glued to the inside of the roof.

I have never seen a reference to the pad in PET, and mine smelled every bit of its age, so I used it as a pattern to make a new one.

As you can see from the pics below, it's very simple, and a pattern is not really necessary. Just get some half inch foam and cut it to fit the roof panel inside the outer frame, and around the rear vent. The bows will be much easier to position once the pad is in place.

Here is a good headliner thread: Restoration Porn: Headliner Install

[psychoideas]

have a look here.
Sunroof Delete

[arrivederci]

Joe has it right. I put a new headliner in my '72 about 2 years ago and they will bow forward, backward, etc when stretching it into place. I replaced my padding and used dynamat products which made it harder (didn't get as much of the bedding effect that Joe mentions). But I eventually got it right. Not the best photos but the point is it takes time to get everything tensioned correctly. Starting off there may be wrinkles and as you tension it, they'll come out and the bows will stay in place.

[al lkosmal]

+1 I went thru the same thought process.............when i 1st trial fit the bows. A bit of a WTF moment for sure. But once installed in the headliner, as you can see in pix above, they are meant to "bow", basically in parallel with the roof profile. Follow the arrivederci method and get many, many clips. Takes time and patience, but it is not too difficult.

regards,
al

[gomezoneill]

Or you can take it to a professional.

[DJN]

Headliner Bow Positions (where 1 is front and 4 is rear, according to the pelican parts listing…….see diagram for Position 3 shown in red. I believe this to be correct as the depth of the end curvature on the bows is deeper to allow the headliner to fit up into the roof/ceiling.



Position 1 and 2 “Green” 901-555-511-20

Position 3 “White” 901-555-512-20

Position 4 “Yellow” 901-555-513-20

Indeed Joefranz's assumptions are correct I have no foam in my inner roof/ceiling but have purchased a Danamat - like sound deadening

Here is a picture showing the tension bars installed in my inner roof. The bows are quite curved and increase in curvature towards the rear. I understand that once I install the headliner and put it under tension that this should disappear, but there seems to be way too much tension and curvature to overcome.

[joefrantz]

You're still ok. The fit is tight, and when stood up, they will contact the roof. The reason the rear bows are bent more is that the roof is more crowned in the rear. Try flexing them into position, you'll see what we mean.

[DJN]

It is physically impossible to flex each of them individually to vertical to follow the roof's contour, as there is just too much wire.......they fly out of position when really forced.....

In the photo above each of the bows are contacting the roof almost completely from tight bend - middle - to tight bend......hmmmm?

Question then: What is the correct amount of tension (by feel with two hands) to get the bows vertical and follow the inner roof contour? I assume it should be fairly easy to do when there is no headliner material or foam in place......mine bows will not do this , thus my problems.

I think I will have to custom fit these ....

[joefrantz]

It takes a lot of effort. I had to get into the car and under each bow to get enough leverage to flex them into place. You are not just pushing the centers up. You have to pull the s-bend at the ends toward the center line of the car to get the angle right. You really need to have them in the headliner pockets to get them positioned right. Look at the pictures in the thread cited above.
Get them close and then fine tune the position by sliding them around and using headliner tension.

[DJN]

Originally Posted by joefrantz

It takes a lot of effort. I had to get into the car and under each bow to get enough leverage to flex them into place. You are not just pushing the centers up. You have to pull the s-bend at the ends toward the center line of the car to get the angle right. You really need to have them in the headliner pockets to get them positioned right. Look at the pictures in the thread cited above.
Get them close and then fine tune the position by sliding them around and using headliner tension.

"A lot of effort", got it! Thank you Joe ! Ok then, I will use the "force" and load up the bows with rubber ends into the headliner and give it a go without my foam in place for a test fitting.....and report back.

[arrivederci]

Originally Posted by DJN

"A lot of effort", got it! Thank you Joe ! Ok then, I will use the "force" and load up the bows with rubber ends into the headliner and give it a go without my foam in place for a test fitting.....and report back.

Note that I have no idea if mine are twisted up like yours or not. Inside the headliner sleeves they seem to be doing their job. So they may be contorted a bit or not. The idea is to have the headliner be tensioned correctly regardless of what the bows may in fact be doing.

[DJN]

Originally Posted by arrivederci

Note that I have no idea if mine are twisted up like yours or not. Inside the headliner sleeves they seem to be doing their job. So they may be contorted a bit or not. The idea is to have the headliner be tensioned correctly regardless of what the bows may in fact be doing.

Thanks arrivederci....This is an interesting point....one doesn't really know what the bows are doing up there hidden behind the headliner above....but the end goal is to get all four of the seams smooth and straight.....which I cannot seem (no pun intended) to do!

If you look at the photo I posted previously (below), I installed the bows without the headliner just as a test. The four bows can each be positioned with their ends firmly in the side holes and notches (meaning the ends are vertical as they should be when locked in), but the excess in the tension bows can laid on the roof/ceiling in either a forward or backward position. In my photo the bows are positioned pointing forward (the bowing U shape end pointing forward). This is not what you want, as far as I can tell.



Thinking about what must be happening up there once the headliner put on with the bows and tension is applied (Note the correct bow order is two greens in position 1 and 2, a white in position 3, and the yellow in 4, see diagram in post #10 ), I come up with this... I would think that one would want to work against the bows to achieve the correct tension effect. This could be done by arranging the bows in position 1 and 2 to lay down pointing backwards (the opposite to those in 1 and 2 in my photo), and the bows in 3 and 4 to lay forward (as in the photo).

Well, I tried this.....and I couldn't get it to work to my satisfaction (I could only get one seam sort of straight).

So, my question to those with successful headliner installs is this:
Which direction do I want each of these bows to lay? Backwards, forwards, or a combination? Or does it matter, although I think it should.

Note: It looks like in the English Gent Video (Gary Wright '68 911) that the two rear bows are roughed in pointing towards the rear. So perhaps having them all laying pointing backwards is correct (the complete opposite from my photo above).

Thank you for your continued help and comments.
Doug N

[DJN]

Originally Posted by psychoideas

have a look here.
Sunroof Delete

Just saw this! Thanks Frank, I will measure my green bows and compare with your 1040mm and Chris' 1025mm .

Do you have any measurements for the white and yellow bows?

Cheers
Doug N

[mickey356]

Doug,
Are you positive the bows (in the pic) are the bows that came with the car? Joe and Arriverderci are right in that the bows are a PITA to get in but those look WAY out of whack. Of course it's always tough with pics but those look too long for sure.
I had better success placing the bows in the headliner and getting some tension front and rear to get them positioned, as someone has already mentioned. Maybe someone here has a set of bows they can measure for Doug?

[DJN]

Originally Posted by DJN

I've just started test fitting new OEM Porsche headliner tension wires/bows for my headliner install... And have run into problems.

First a little background, my car is a 1972 911T non-sunroof coupe and it has not had a headliner in it for 20 years or more, as it was set up as race car. So I have purchased the correct part numbers for the tension wires (and rubber end covers) which are also coded by color: two greens, a white, and a yellow.

These are new bows as stated in the first post.

Yes Sir, I am trying to find some other's measurements (tip to tip) for Yellow (my bow is ~1065mm) and white (my bow is 2075mm) bows....I have the range of measurements for green - 1025 to 1040mm....mine is 1040mm....so it looks like I may have to trim.

Note that the measurements inside the car between wire locations are as follows:
Position 1 (green) : ~1000mm
Position 2 (green) : ~1000mm
Position 3 (white) : ~1020mm
Position 4 (yellow) : ~1030mm




Thanks,
Doug N

[Tippy]

Originally Posted by gomezoneill

Or you can take it to a professional.

"All experts started out as beginners".....