I got pulled up a couple of times at a Javelin trackday this week as I was "very close" to the drive-by dB limit.

Unfortunately there is no static test at Blyton, so I don't have a reference point for comparisons.

My system is as follows:

Decat downpipe to 2.5"
2.5" deresonated centre section
TSL Group N Backbox

I've still got my Prodrive backbox locked away, which I know is safe for trackdays - but rather than messing around swapping backboxes for track days, I thought about fitting a resonated centre section.

Is this likely to bring my volume down, or just change the tone? Are there any "go-to" centre sections worth knowing about?

Here is how I sounded, for reference:

I love the tone, but it's no good to me if it's going to cause me problems at track days

 

It should bring the volume down, that is the whole point of it. Though a decat and the Group N back box are both pretty aggressive in themselves.

For comparison my 2005 STi has a pretty loud Afterburner Vortex back box, high flow sports cat but resonator still in place and is no where near as aggressive as yours sounds.