Fernando's 2016 GMC Sierra HD2500 with Octohorn Train Horn train horn install exterior photo 1

Fernando's 2016 GMC Sierra HD2500 Octohorn Train Horn install gallery photo 2

Fernando's 2016 GMC Sierra HD2500 train horn installation detail with Octohorn Train Horn photo 3

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Featured Install

Octohorn Train Horn

Fernando's 2016 GMC Sierra HD2500

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Owner Fernando

Year 2016

Vehicle 2016 GMC Sierra HD2500

Fernando R. gave his 2016 GMC Sierra HD2500 a serious sound upgrade by installing the HornBlasters Octohorn Train Horn. Mounted under the truck bed, the Octohorn keeps the installation clean and out of the way while delivering the unmistakable, attention-grabbing blast HornBlasters is known for. Evolved from the Katrina train horn, this is one eight-bell horn—not eight separate horns—tuned as a single, deep locomotive chord in stealth black.

The under-the-truck-bed location makes excellent use of available space on a Sierra HD without sacrificing performance. The Octohorn Train Horn is a stand-alone horn (part AH-C8B): you get the eight-bell assembly, a pre-installed 12/24-volt electric air valve, and mounting hardware, but you still need a compatible onboard air system to honk. HornBlasters lists it at about 17″ long, 17.5″ wide, and 16.75″ tall, roughly 30 lb, with a 1/2″ NPT port—compact enough to tuck under a 2500HD bed if you confirm ground clearance first.

Awesome work, Fernando—thanks for choosing HornBlasters and sharing the build. Want tank, compressor, and wiring in one box? The Octohorn product page also lists the Octohorn 544K Train Horn Kit and a HornAir 544K onboard-air add-on (5-gallon tank and 1NM compressor) so you can finish the system without piecing hardware together.

Feature Highlights

Octohorn Train Horn (AH-C8B): one eight-bell horn in stealth black, tuned for locomotive-style depth and harmony
This 2016 GMC Sierra 2500HD install: under-bed mounting for a clean, out-of-the-way HD-truck layout that still projects serious volume
Stand-alone package includes the horn, pre-installed 12/24-volt electric valve, and mounting hardware—add onboard air to complete the system
HornBlasters lists ~17″ × 17.5″ × 16.75″, about 30 lb, and a 1/2″ NPT air port—measure spare-tire, exhaust, and hitch clearance before you hang it
Finish the install with the Octohorn 544K complete kit or HornAir 544K add-on shown on the Octohorn product page

HornBlasters Shocker S6 544K Nightmare Edition Train Horn Kit

PRODUCT

PRICE

Sold out

UP TO 1500% LOUDER

UNLIMITED HONKING

ZERO
DELAY

CAPABLE ONBOARD AIR SYSTEM

OCTOHORN PRESENCE FOR YOUR SIERRA HD

The Octohorn Train Horn delivers the same under-bed, eight-bell blast Fernando R. showcased on his 2016 GMC Sierra 2500HD. Plan a compatible air system and valve wiring before you order, confirm under-bed clearance on a heavy-duty chassis, then follow HornBlasters’ instructions so warranty coverage stays intact.

SPECIFICATIONS

Part Number	AH-C8B
Voltage	12/24-Volt DC
Horn	HornBlasters Octohorn Train Horn
Horn Length	17" (431.8 mm)
Horn Width	17.5" (444.5 mm)
Horn Height	16.75" (425.45 mm)
Horn Weight	30 lb (9.07 Kg)
Port	1/2" NPT

Frequently Asked Questions

It is a stand-alone horn. The Octohorn Train Horn listing includes the eight-bell horn, a pre-installed 12/24-volt electric air valve, and mounting hardware—you still need a tank and compressor. Fernando R.’s 2016 Sierra 2500HD uses that horn-first path under the bed. If you want everything in one box, use the Octohorn 544K Train Horn Kit (or the HornAir 544K add-on) shown on the same product page.

One horn with eight bells. HornBlasters evolved the Octohorn from the Katrina train horn and tunes those eight bells together as a single chord. That is why Fernando can hang one compact stack under the Sierra bed instead of plumbing eight separate trumpets.

Fernando’s install shows it can, with a clean, out-of-the-way layout. HornBlasters lists the horn at about 17″ × 17.5″ × 16.75″ and 30 lb, so you still need to check spare-tire hardware, exhaust, hitch, and ground clearance on a 2500HD before you mount it. Isolate vibration, protect the 1/2″ NPT line, and keep the pre-installed valve away from heat and road spray where you can.

Size the tank and compressor to the honk time you want and to the 1/2″ NPT port on the horn. HornBlasters’ ready-made path is the Octohorn 544K complete kit—or adding the HornAir 544K onboard air system (5-gallon tank and 1NM compressor) from the Octohorn Train Horn product page. Always re-read the live spec tables and add-on notes before ordering.

HornBlasters backs the Octohorn with a 1-year manufacturer’s defect warranty. The current product listing also notes that some batches may have finish blemishes that do not meet their usual cosmetic standard, while sound and performance remain the same. Confirm the live finish and warranty language on the Octohorn Train Horn page before you buy.

SHARE YOUR HORNBLASTERS SETUP

Running an Octohorn, Shocker XL, or another HornBlasters system on your Sierra or Silverado HD? We’d love to see it. Submit photos and details of your installation for a chance to be featured in our install gallery.

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