i decided to install a set of Hella Twin Trumpet Horns #007424801 on my 996TT the other weekend while cleaning the radiators. The main reason was, the wimpy stock horn didn't really 'fit' the car, and these 'command' a bit more respect Comparison at the bottom of the post.

First, I couldn't find any photos of the stock location, so hopefully these remain for internet eternity. I'll keep it brief because it's not a difficult job to do and minimal tools are required. I began with removing the front bumper cover as described here: .

This shows the location of the OEM horns:


Narrowed in:


This is the toughest part, using a 13mm open-ended wrench to remove the nut circled in red:


Next, with the horn bracket loose, I lowered the assembly until I could remove the nut holding on the lower horn:


Lower horn unbolted and removed. Now you can remove the upper horn with the horn bracket still attached:


Stock horns and horn bracket next to the Hella horns, pretty similar in size. Remove the brackets the come with the Hella horns:


Back side of Hella horns with 1/4" spade connectors shown (these re not included on the kit, but easily found at most auto part stores):


Hella Horns with little wire leads I made up:


Close up of wire leads, one note is that polarity and position do not matter on these horns:


Stripped back insulation on stock wiring:


Soldered in wire leads, retaining the stock plug in case the need to go back to the OEM horns:


Wire leads complete and protected with 3M Super 88 electrical tape:


New wire leads attached and OEM connectors taped up for protection:


Mounting is the exact reverse of removal, I did however replace the stock horn bracket mounting locking nut with a serrated one, for easier installation:


Tone comparison between the stock horns and the Hella horns. The Hellas are quite a bit louder, but difficult to discern in the videos.

Stock Porsche 996TT horns: Hella Twin Trumpet horns:

 

cool, nice video, thanks for posting bumper removal - I'm going to take mine off this weekend and clean it up or just check, Because i found tons of crap in my air intake box. also in my drives side Intercooler/tons of cigars, someone was just throwing them out while driving and it was sucking them back in through the hole like a vacuum-

 

This one next time

 

Way too much work for a car that wont even play La Cucaracha