short of installing full on pneumatic air horns what are folks replacing these meek horns with?
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Moo Sex did you check the voltage reaching your horn by chance? I was surprised to find my headlights were only getting 9.2 V and adding relays got them up to 12.88 V.
Could horns suffer the same voltage drop ? Just wondering.
The Wolo "Bad Boy" is popular. It's a self-contained air-horn designed for motorcycles. It plugs right into existing wiring and mounts with one bolt. I was able to use existing horn bracket and didn't even need to drill any holes.
Groit's Garage has some nice one's.
Non-air and loud horn..
http://www.griotsgarage.com/pr...s.do?sortby=ourPicks
And here is another self contained air horn..
http://www.griotsgarage.com/pr...s.do?sortby=ourPicks
I can't vouch for either of these products personally, but I have never been disappointed with anything I've bought from Groit's.
Harbor Freight even has the Wolo Bad Boy - or do search on Amazon. About $30 black and $38 chrome.
I replaced my horn with Wolo Super Horns 306 2t, like these:
http://www.summitracing.com/parts/WLO-306-2T/
I painted them black, wired them up with a relay, and mounted them behind the horn grills.
I can't vouch for whether they really put out 120 db like they say they do but they're pretty loud.
I use two Bad Boys, great sound and LOUD!
I went with Fram air horns...really loud!
Moose: I used a pair of Subaru horns from an old Legacy. They were cheap(junk car=free!) and are tuned off of the harmonic, so the dissonance gets your attention. They are loud, but not too much, if you know what I am trying to say. I did put a relay to them, as they are grounded through the mounting bolt. The relay turns the grounding VW column into a switched positive for the horns, relay mounted on the front beam along with the horns on my Spyder. Time spent, about an hour and a half, cost was a few bucks for the relay.
FIAMM not Fram I meant to say. I've got a pair of the ones Wolfgang linked to above and a pair of the air powered trumpet horns, both operating off of relays.
I use this unit. Powered by a relay.
Several people mention using a relay, why?
Short answer is that a relay is an electromagnetic switch that allows you to put full amperage to the lights or whatever appliance you are running without having to run BIG wire to do so. The stock wiring circuit and switches in your car's electrical system corrode over time, decreasing conductivity. This means that your lights may not get full battery voltage, making them much dimmer. The addition of a relay brings back full amperage to the lights. There used to be one or more threads on this subject. To learn more, there are threads on the net, including youtube.
As Jim said - an electric device that makes a high electrical draw will actually burn out a switch. The contact points arc each time device is turned on and off. Cheaper the switch the faster it goes bad. I've seen driving lamp switches actually burned/fused on. With a relay those hungry devices can get full power - so horn is louder or lights brighter.
This site has a great explanation under the subheading "relay basics - 101":
http://www.rattlebars.com/mtz/hornrelay.html
This site is also pretty helpful:
http://www.dormanproducts.com/...b/brand/CTp5ver2.pdf
(very clear diagram with suggested wire gauges, fuse location, suggested connectors, etc.)
This site has a lot of wiring diagrams for the 356 with animations. Here's a link to the horn circuit:
http://www.cyberwerkstatt.com/...y/T2_Pgs/T2_Horn.htm
Ok, for my horns which are already grounded through mounting, I had to use a relay. In Ted's picture above, term 85 or ground is connected to the column switch, which grounds when the horn button is pushed. The 12v constant hot is connected to term 86 AND 30. Term 87 is connected to the horns. This is how you change a ground switched input to a positive switched output. It can work the other way too if needed. Like others have said, relays are great for saving switches and giving full power to devices. I have relays on my turn signals, ignition, coil, breather solenoid, rev limiter, headlights, backup light and my starter switch on my Spyder.
I went a bit further and installed two relays for the important circuits like ignition and coils. The relays are side by side so if one fails I can just unplug it and plug into the other. They're cheap so its not a big deal and even if I never need to use the second one at least its there. I know...more money than brains.
great info guys. My headlight seem pretty bright but the horns are def' weak. a relay is in order.
Sounds like Danny and I travel in parallel universes. I have relays for ign, cockpit 12v, alt 12v, horn, tail lights, headlights, brake lights and driving/fog lights (separate relays for each). That takes all of the stress off of the dash switches so they should last forever and since I cheaply used re-cycled 1969 VW switches, I thought that was a good thing.
The only thing which worries me is the seemingly unique '69 VW turn signal/emergency flasher unit that I used. I completely refurbished it when building the car, but it won't last forever and will have to be replaced with an electronic unit when it goes. No big deal, just an added pain because the newer ones expect the dash blinkie light to work differently.
Gordon, I used relays, a couple diodes, and one HD flasher relay, and have turn signals, 4 ways, and the single dash indicator wired up WITHOUT the factory unit. Should last forever, everything is soldered together. I'll email a pic, can't figure this out no time right now.
If you take a look at and read the fine print in the diagram above, note the subtle
difference in 87 and 87a positions. Relays (I used Bosch to help my headlights, one each for high and low beam 
also come in a "double 87" variety. This is handy when you need two things to come on simultaneously such as headlights, tail lights or brake lights. Double check when at the parts counter because the guy behind the counter might not be right on top of things.
I don't know how that smiley thing got there when I hit the closing bracket key.