Arrow Exhaust

Finally decided to get Arrow headers. Arrow Exhaust - Thruxton

I bought the 71658MI as it retains the OEM catalytic converter. Its a legal requirement to have it in place. Otherwise a hefty fine. The flexibility of this header is that its easy to install and can work with any aftermarket slip on.

When I first got my bike, it came with the Triumph OEM Vance & Hines exhaust as part of the bundle. During the removal, I noticed that the air way is blocked, ALOT.

And its kinda welded internally during the making process, which makes it not removable. From what I am reading online, this spec is limited to UK imports.

The OEM exhaust had a tiny passageway, kinda spiralled probably to baffle the noise. Its was straight thru in my opinion versus the V&H and decided to go back with OEM. The OEM was louder, more airflow, but just slightly heavier than V&H.

I had previously used the X pipe before and was not a fan of the performance. Looking at it again, the exhaust airflow is not free flowing. First the gas have to make a bend to reach the X point at which turbulence occurs before its channeled out. In any case, it flows better than the Catalyst but not the best.

The arrow header does not allow gas to go thru the Catalyst at all. The exits are capped and the front is used as a mount support only.

In the 71658MI model, there is no crossover / link pipe. As such, each cylinder is directly routed to a single pipe and exit.

The 716645MI and OEM headers have a link pipe.

The rear catalyst port that will be capped. The cap is provided.

This step is not necessary at all. I removed the OEM wire mesh gasket and tried to transfer it to the cap. As there is no airflow at all, this is not necessary. I only learnt when I finally saw the Arrow header that there will be zero airflow.

Somehow made a ring and capped the ports. Again, do not do this.

The section on the Arrow header that links to the front catalyst port. I only saw this after I did the rear ports.

When you mount this, the OEM clamps are not required. It seats snug.

The full length of the Arrow header was ALOT lighter than just the OEM front header pipe alone.

Those with X pipe may argue that the Catalyst is in fact heavier. I don't have a choice.

The Arrow header also has the Oxygen sensor bung.