Jerry
PowerDork
6/14/23 6:52 p.m.
After no less than 3 separate accidents in 22 miles on 75 causing slowdowns after work, yet another SUV turned left right in front of me into a parking lot trying to sneak in with two other vehicles. The horn on the BRZ is laughable (Revving would have been louder) and the passenger's face was amused.
Even the Hella's I tried on the WRX were just kinda louder (yes they were wired in correctly for max oomph). I'm thinking air horn, multiple trumpets. Something that's going to downright jolt someone in their seat. What are some options? (Technically I want two, haven't used the horn in the 944 but I'm sure it's worse.)
6v horn on 12v
we did that with our older VWs to give us a chance of not getting run into buy people changing lanes towards us .......
When living in Toronto in the 80s and driving a Mazda GLC (Beep-beep) I installed a junkyard horn from a Ford pickup. It helped a lot.
I was looking to answer the same question for my bugeye sprite, because it's small enough to literally disappear around some modern pickup trucks.
Wound up going with a self contained dual note air horn. I'd have to go into the wife's Amazon account to find the specific one I got, but you can probably find success just looking around for air horns and reading reviews.
In reply to Jerry :
The answer is Cadillac 4 Note Horn. It and other GRM chatter can be found in this thread.
^My apologies for the life sized images.
02Pilot
PowerDork
6/14/23 8:29 p.m.
I put these PIAA horns in my ND a couple weeks after I bought it. Definitely louder, and a much more attention-getting tone. Probably not as loud as an air horn, though.
I've thought about buying a used electronic police air horn many times. You know, the jarring "BRRRTT BRRRRTT" as a police car clears an intersection.
Most of the ones on Amazon are cheap Chinese copies that don't even come close to the sound or volume of a real one.
They are legal as they aren't a siren. And there is no mistaking the sound.
I'm a fan of air horns, they give the person the impression they're about to be run over by a dump truck 
Be careful with your new air horns. Nowadays, they are enough to get you shot at.
When I had my Miata, I went to a junkyard and got the horns from an older Cadillac. That worked pretty well, but I think horns from a full-sized pickup would also work pretty well.
A student of mine had one of these. It was awesome. I like the dual volume. I have one on order for my Mazdaspeed3.
This is what I had on my Miata: https://3maudio.com/horn.html
newold_m (Forum Supporter) said:
This is what I had on my Miata: https://3maudio.com/horn.html
I had one of those in my first Miata, just ordered another one for my current Miata.
Rodan
UltraDork
6/15/23 8:02 a.m.
I have used the Stebel Nautilus Compact on a couple of Miatas now. Has the typical 'euro sports car' sound, is loud, easy to wire and compact. About $50 on Amazon
I put these on everything. 130db and they are a fairly annoying pitch so they grab attention nicely. $25 with the relay kit.
https://www.amazon.com/gp/product/B07S92C6V2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I enjoy reading the translated product descriptions.
The factory BMW horns on the E38 are reasonably loud. For the Jeep, I left the half-decent stock 2 tone horn in place and added a set of the Caddy 4 tones to that. It's loud, but not truck with air horns loud. But the sound is very distinctive and I've never seen a person not react sharply to it.
If you've got lots of space to work with, you can go for air horns, or the electric trumpet horns sold for boat use. Either of those can get you into some options that are bordering on painfully loud at close range.
Jerry
PowerDork
6/15/23 2:03 p.m.
I forgot I bought some BigBoy horn of some sort for the Abarth that didn't get used. I asked the dealer tech (that had one himself) to install it when he had the front end off for something, but he said he couldn't get it mounted without some special fabbing of a bracket.
See if it's still in the garage handy.
Found something online for reference:
A few years back, I went to the junkyard with a 12v battery and started testing all the horns on the biggest American iron in the place. Ended up with a collection of very loud horns for very little money. And had a pretty fun day.
I also have a set of the Cadillac 4 notes off one of my old cars, just for fun. I've also used air horns in the past, but have found they have a service life as the compressors eventually fail.
stanger_mussle (Supported by GRM undergarments) said:
I've thought about buying a used electronic police air horn many times. You know, the jarring "BRRRTT BRRRRTT" as a police car clears an intersection.
Most of the ones on Amazon are cheap Chinese copies that don't even come close to the sound or volume of a real one.
They are legal as they aren't a siren. And there is no mistaking the sound.
I like this. There are resellers that specialize in selling decommissioned police vehicles. They usually have a good collection of take-offs, I'd go looking there. I'd make sure you're not just buying a speaker, the BRRRRT might be generated by a siren as one of the optional sounds.
