Restoration of '70 2800CS 2270407

mulberryworks said:
Further investigation of the trunk gasket lip has revealed the extent of the corrosion. Not good I'm afraid. I should have suspected other shoddy work when I found that one of the horns was a later model that was connected to the stock wire harness with duct tape. Did I mention I hate duct tape?
It's going to take a while to get the gooey tape residue off the car to allow me to see just where the good margins are. I'll not cut anything out until I have the car body properly braced. No point in introducing weakness and possible distortions until I'm ready to weld in new metal.

I'm hoping to find a replacement body part from another car but since this is virtually the rear edge of the parcel shelf, I suspect the demand for parcel shelves will have dried up the supply for good trunk lips. And I don't know the failure rate of the trunk lip but I don't think this is a common issue.

If I can't find a replacement part, it might be possible to modify one from an E3 to fit, but that would require a lot of cutting and bending, then rewelding. It might actually be easier to create it from scratch. I have a bead roller and a lot of patience.....

Ian

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Ouch!!!!
 
ScottAndrews said:
Ouch!!!!
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Making a new section of trunk gasket lip will be an interesting project but making the body stiffening member that runs under the parcel shelf will be another level. Both ends are rusted out either from water from the trunk lip or from the rusted corners of the rear window frame and I'll have to fabricate new metal to weld in. That task alone might be sufficient to prompt me to build a rotisserie because I don't think I'd like to lie in the trunk and weld metal above my head.

Oddly enough, very early 2800CS had drains in the corners of this member, but they were removed at some point during the manufacturing run.
 
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The horns that came with my coupe are old, but not identical. One might be original as it was easy to take apart and clean to get it working again. The other was not so easy to get apart, but looks very similar. I couldn't get it working satisfactorily.
My question is what frequency were the horns that shipped with our cars new? The ones I have are 330Hz & 415Hz.

I have bought a pair of new Bosch horns that are 420Hz & 510Hz. They are substantially higher in pitch, though realistically, that may cut though the audio clutter better than the lower tones of the older horns.
Personally, I kinda prefer the sound of the lower twin tones. I've generated simulated horn sounds with Audacity by creating two channels of sawtooth waves at each frequency.

Does anyone with an original coupe know the frequency of their horns? It's a pretty minor detail, but I like the idea that my coupe could sound like new, with the correct horn frequencies.

Thanks.

Turn your volume down!

330Hz & 415Hz
420Hz & 510Hz
Oops, I thought you'd be able to play the sounds in a browser window, but you can download them if you want, they are small.
Hmm, a Google drive issue to look into.

2800CS BMW E9 Horns 415hz & 330Hz.jpg
 
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Yes, the 410Hz seems fairly commonly available as the low tone of a twin tone pair. Unfortunately, the listing above doesn't give a frequency for the 846 low tone horn. Most vintage horn references i've found simply list the horns as high and low.
Thanks.
 
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