Further observations on KH Stage three:
On further driving, there are days when I pity the pedestrians as I sit at the lights. It IS loud and am planning to ask KH if the down turned pipe ends (supplied but not fitted) might help a little. Defo earplugs for me but sadly can't issue them to the people walking by.
The noise is also hardcore in as much as there's lot of popping, spitting and farting on the over run...snarly / gnarly....and less suitable for the peaceful runs through the countryside.
The newfound performance is definitely there...and felt.