Replace horn with siren?
 

On my old truck, I had alarm installed with a 140 db siren. Man that was LOUD! Now I've got this wanky horn on my camaro. Is it possible if I just find a 140 db siren horn and take off the horn ad wire it up? I'd like to use horn as siren and when my regular car alarm goes off, siren comes on like honking. Possible?

well I think haveing an actual siren full time as your horn wouldn't be good. HOWEVER, here are a couple of options for you.

FIRST: our cars actually have TWO horns, one on each side. That you could do is remove one of the horns and put your siren in its place, take the normal hot wire going to the siren, cut it and run a wire to the dash and place a toggle switch in it and then run it back to the original power wire for the siren.....TURN IT OFF for normal running so when you use the Horn, all you have is the one stock horn. when you get out of your car, it will arm the siren as if your alarm goes off......the siren and the othger stock horn will be going off.

SECOND option: install a 140 db, legal air horn for use as your cars horn. I have done ecactly that.....same tone and volumn as Tractor Trailer (Semi's) horns. Here is the complete DIY with video. Below the video, is the Install Instructions, where I got it, EVERYTHING needed for the install.

http://www.camaro5.com/forums/showthread.php?t=157184