Targa body dimensional data - windshield header to Targa bar

[Otter74]

Where can I find dimensional data for a targa body? I’m sure it exists (e.g. body shops would need it) but I don’t know where a lay person can find it. I’m working on top fitment on my Targa and I’d like to see what the nominal dimensions are for the Y-axis distance between some reference point on the windshield header and another on the targa bar.

Alternatively, if someone(s) with a Targa was willing to measure their car, I could compare mine to a known-good car. I have no reason to believe my car ever experienced an event that would have tweaked the windhiseld frame, but I’d like to measure my car and compare it to what it should be.

I’m trying to get the front of my top to sit down where it should - it’s a little high - and the only way I can get it to do so is to remove the front locating pins, after which it is easy to get it to go back all the way until the rear beading touches the Targa bar, and the front edge goes down to where it should be. With the pins in, it’s about 4-5mm too far forward. I can just hog out the locating holes for the captured nuts for the front pins, but I shouldn’t *have* to.

[darrin]

otter74 -- If I recall correctly, the current Porsche front seal for our pre-964 Targas is actually the 964 seal which, if not manually trimmed before installation will cause the front of the targa top to sit too high. Dan Pectel (carsinc on pelican) has developed an aftermarket seal that lets the front of the targa top sit properly. FWIW

[Otter74]

@darrin I have Dan Pechtel’s seal on the car - I had it installed when I had some work done on the cowl and a new dash and windshield put in. The problem that I need to tackle first is getting the top back all the way until the beading touches the Targa bar. It does this without problem if I remove the pins, but with the front pins in it’s 3-5mm too far forward.

[rwest]

I have a 77 and just measured it.

Pushing the hook of the tape against the outside edge (rim) of the rear metal pin socket and measuring to the center of the front pin socket, I got 26 1/4” both sides, thankfully!

Diagonals pushing the hook against the socket rim in back and going to the center of the front socket again, I measured 45 1/2” both diagonals equal once again.

Car has been sitting top off for about a week.

[Otter74]

Thanks, Rutager! I’ll be at the car tomorrow and will measure it.

[Otter74]

I got 26 1/2 on the left side an a hair (maybe a 16th) under that on the right side. Diagonals were 45 3/8 and 45 5/8. Going to measure again tomorrow to see whether the variation I see side to side is within the error range of repeated measurements. But I do seem to have an extra quarter inch over Rutager’s car. I’m curious to know what other cars are like.

[eflight]

Posting this, hope it helps, note bottom left photo


Looks like the forum shrinks it to reduce the size. The copy I have is much better

Here is a link to the original PDF and jpg you should be able to read the numbers on these

https://drive.google.com/drive/folders/1m_69j8w1ycSYy7VXhk7c04-QTQM0Cmby?usp=sharing

[rwest]

Originally Posted by Otter74

I got 26 1/2 on the left side an a hair (maybe a 16th) under that on the right side. Diagonals were 45 3/8 and 45 5/8. Going to measure again tomorrow to see whether the variation I see side to side is within the error range of repeated measurements. But I do seem to have an extra quarter inch over Rutager’s car. I’m curious to know what other cars are like.

Otter,

Differences in tape measure accuracy and tape sag could explain such small amounts.

The drawings are great, but I cannot get it to explode up without blurring the numbers and my quick google search didn’t help much either. I wonder where a larger picture might be found or what publication it came from?

Rutager

[eflight]

Originally Posted by rwest

Otter,

The drawings are great, but I cannot get it to explode up without blurring the numbers and my quick google search didn’t help much either. I wonder where a larger picture might be found or what publication it came from?

Rutager

Looks like the forum shrinks it to reduce the size. The copy I have is much better

Here is a link to the original PDF and jpg you should be able to read the numbers on these

https://drive.google.com/drive/folders/1m_69j8w1ycSYy7VXhk7c04-QTQM0Cmby?usp=sharing

[rwest]

Link worked great! I was able to enlarge and still read numbers.

Thanks

[Otter74]

Yeah, a sixteenth is something I’m going to provisionally consider within a reasonable error range. A quarter inch, not so much - if 26.5 were nominal for what you measured, it would account almost perfectly for the difference between where my top is and where it should be. My measurements were repeatable but it’s hard to be precise.

@flight Thank you - that’s perfect. I’ll go measure the best I can to that reference plane. 685.5mm comes out to almost exactly 27 inches.

I’m willing to hog out the locating holes for the front pins on the top if I have to, but only if I know for sure that the points on the body that the top attaches to are where they should be.

[SpyderMike]

I was unable to install my rebuilt Pechtel targa top targa with new proper seals until I removed one down pin. I gave up trying to figure out why. To be fair, the car had been in a few front and rear hits over the 36 years that I have owned it.