That insert looks great.
But at the end of the day the outlet to the right pipe is only about a metre away from your ear. It will be loud no matter what.
When I first had my car on the road I ran the side pipes but had to use ear plugs.
I got a DB reading on my meter of 108db at my ear at 100km per hour.
The LPG also stunk when I had to sit in traffic.
So now I run the same system but have it exiting behind the rear wheel arch.
No prob's with noise any more
So to sum it up.
If you like the active side pipes.
No need for expensive exhast modifications.
$5 for a dozen disposable ear plugs...easy
And the money you save, put it on the bar for the next time the Vic's hit the Mount.
