Description
650Z-32T D&D Billet Cat Exhaust 2-into-1 Chrome for 2017-Newer M8 Harley FLH/FLT Trike Models
This D&D Billet Cat Exhaust will get you some sound from your M8 motorcycle. Check out this sound clip we did after installing it on our 2017 Road Glide Special:
This exhaust will NOT fit 2023 CVO Road Glide® or CVO Street Glide® 121 models with VVT.
Built for 2017-Newer M8 Touring Models
The D&D Billet Cat is a full 2-into-1 exhaust system made for 2017-newer Harley-Davidson® FLH and FLT Touring models. In addition, it includes the Trike Extension Kit, so it is ready for trike applications.
First, the stepped header design starts at 1 3/4″. Then it increases to 1 7/8″, and finally steps to 2 1/8″ at the collector. After that, it transitions to 2 1/2″ at the muffler connection. Because of this design, the system improves exhaust flow and helps the engine breathe better.
As a result, riders see stronger throttle response and better mid-range power.
Choose the Right Baffle for Your Build
You can choose between two baffle options depending on your engine setup and sound preference.
Vortex Wrapped Baffle (2 1/2″ Core)
This baffle works best on stock engines up to 114″.
It delivers strong torque while keeping the sound deep but controlled. Therefore, it is a great choice for daily riders or mild builds.
Big Bore Baffle
On the other hand, the Big Bore Baffle is designed for larger engines. It works best on Stage 4 114″, 117″, and aftermarket 120″+ builds.
Because it uses a 2 1/2″ all-metal perforated core, it produces a much louder and more aggressive sound. However, while it increases volume, some riders may sacrifice a small amount of efficiency compared to the Vortex option.
So, if you want maximum sound and have a larger engine build, this is the better choice.
Designed for Performance Builds
D&D’s Chief Engineer has seen strong gains in mid-to-high RPM power on modified engines. For example, Stage 4 114″ and 117″ builds respond very well to this system. Likewise, aftermarket 120″+ engines paired with the right cam and proper tuning show impressive results.
In fact, this exhaust truly comes alive after a cam upgrade. Once we installed a T-Man T216 (0.475 lift) cam, the sound became deeper and the power delivery felt noticeably stronger.
Everything You Need for Installation
The M8 Billet Cat full system includes:
-
Heat shields
-
New exhaust gaskets
-
Mounting hardware
-
Your selected baffle
-
Quality flanges (no need to purchase separately)
-
Both 18mm and 12mm O2 bungs
Because it includes both O2 sizes, it works with wideband auto-tuning systems like ThunderMax® AutoTune and Dynojet® Auto Tune.
In addition, the 4″ muffler housing adds a clean, strong look to your Touring bike or trike.
Stronger Torque. Deeper Sound.
Overall, this system improves low-end torque, sharpens throttle response, and delivers the deep tone Milwaukee-Eight riders expect.
Most importantly, when you pair it with a cam upgrade, performance improves even more. That’s why we offer proven cam packages and install them at major events from our show truck.
If you want real performance — not just noise — this system delivers.
