Type Three Tuning Page -- Headliner/Roof

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Sunroof front drain
Sunroof rear drain

> Anyone out there tried the
Innovations in Fiberglass hinge covers?

I bought the dual hinge covers (not the early style one-piece). They are not very flexible compared to the stock plastic covers, which is a negative because the mounting flanges aren't wide enough. Yeah, they look good, but installing them was aggravating for me because there were no mounting holes (which is normal with fiberglass parts) so it was a matter of fitting, marking and double-checking before drilling. And the holes are too close to the edge of the material. On the right hinge cover only three screws hold it in because the fourth would've only been half-way holding the cover. If they made them with more material on the mounting flanges then they would be a better deal.

The rear compartment light is missing/broken. What part number do I need?
The "rear luggage compartment" lights are 111 947 111D (Beetle type interior?) for models 361-368 (Squarebacks), and 151 947 111A (Beetle convertible) for 311-314 (the Fastbacks and Notches).

Full length canvas ragtop
I got mine from StreetBeat. They are located in Arizona and their phone number is (602)254-4332. I bought the kit in 1996 for $640. It comes complete, including instructions. Actually, the kit I got is meant for a Bus because I wanted everyone to get air :-) If you are comfortable with removing sheet metal from your roof then you could probably install it yourself in the garage on a weekend. I didn't have the luxury of a garage at the time and body work isn't my specialty so I had a body shop install it for me. The shop manager said it took 22 hours and it cost me about $700, however, they were working on it over a two week period when they had the time and I believe he over charged me so get an estimate before you have a shop do it (take the installation instructions with you).

They have canvas and vinyl and in a variety of colors; I think the canvas is much better looking (that's what I have). Yes, it's waterproof or I wouldn't have installed it in my daily driver since Oregon gets lot's of rain. Wind noise will increase, naturally, but it only becomes noticable out on the highway.

Top closed  Top 1/3 open  Top open  Top inside closed  Latch mechanism  Track

-- Additional Info --
Naturally, when you remove a large sheet of metal like the center of the roof you will loose some structural integrity. In this case I feel that the loss is very small, like, you won't notice it. The ragtop is still surrounded by several inches of roof. Only if you were to make the car into a true convertible would you have major structural losses that would require additional reinforcement. Also note that a smaller ragtop will leave more roof and less structural loss.

John's Input...
I have a bit more interesting information regarding this. Dave Hall sent me a page from the test report he has on the 69 Fasty. It lists the Torsional Stiffness of the Fasty as 15,160 ft-lbs/deg and the bending stiffness between 18,180 and 31,250 lb/in depending on whether you measure on the pan or body, respectively.

Now this doesn't mean much until I put a little perspective on it. So here is a short list of stiffnesses for other cars from some Ford data that I came up with...

Vehicle Stiffnes Comparison
Car Torsional Stiffness (ft-lbs/deg) Bending Stiffness (lb/in)
1969 VW Fastback 15,160 18,180 to 31,250
1989 Mustang w/o glass 3,464 33,015
1989 Mustang Convert. w/o glass 1,559 16,568
1987 Honda Accord 6,100 54,600
1987 Honda Accord w/o glass 4,800 55,000
1990 Toyota Cressida 7,360 77,240
1990 Toyota Cressida w/o glass 4,634 72,029

A couple of notes of interest:
1. The 69 Fasty has a very good torsional stiffness. The highest on the whole list was 16,675 ft-lb/deg! Higher is usually better to a point. I checked around and today's cars seldom get much above 15,000.

2. Chopping the top off has a significant effect on both torsional and bending stiffness as can be seen in the 89 Mustang data. The contvertible body had been reinforced already, but it still cut the stiffnesses in half!

3. Filling in the large holes in the body (such as window openings and sunroofs) has a significant effect on the torsional stiffness as shown in the Honda and Toyota data. The glass in question is the windshield and rear window. keep in mind too that glass is about a third the stiffness of steel and although the glass is thicker than the steel used in the roof panel, their specific stiffnesses would be similar.

In general, the vehicle is constrained at the suspension hardpoints (whereit attaches to the body, in the case of the T3 probably the outside edge of the front beam and the upper rear shock mounts) and then loaded by either twisting the front relative to the rear (torsion) or loading the center of the body for bending. The bending stiffness is the resistance to bending between the wheels front to rear. They generally do not concern themselves with the front and rear overhang since it contributes very little to do with the overall NVH and ride and handling of the car.

The torsional stiffness of the vehicle structure, in combination with the suspension, is very important for cornering behavior of the vehicle. Remember that most of the feedback to the driver comes through the body structure. The bending stiffness is also important for vehicle ride and handling as well as the NVH.

We do not test static bending and torsion so much any more. Now we suspend the body structure by bungee chords and hit it with a calibrated hammer (seriously) and measure the vibrational response of the vehicle with accelerometers and look for natural frequencies of the structure. We want these natural frequencies to NOT align with road load frequencies and engine/transmission frequencies. Otherwise they would excite the natural frequencies of the body structure and the passengers/driver would feel it. This is why generally speaking you want the body as stiff as possible since most of the road load and engine vibrations are at lower frequencies.

John Jaranson
'71 FI Auto Fasty