Use a pair of Dynomax bullets as resonators...it will not change the tone at all but it will reduce the volume at idle several decibels...and at WOT they will have nearly zero effect on performance. They are like turning the amp volume on a Marshall stack from '11' down to about 7 1/2

I think If you live in a residential neighborhood you need to show some respect for your neighbors....I can't stand incessant Dog barking and kids blasting Rap at all hours, so at least to some degree I can respect someone not appreciating our 'Mechanical Music' as much as we do.