Thermal is a stright through design, similiar to N1 or Tanabe Racing Medalion so it will be loud. Turbo's make pretty good mufflers so it probably won't be as bad as if you didn't have one but it won't be quiet like a WS or large muffler style exhaust.
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Andy - Reinstated
Hybrid Forum Moderator
'06 Subaru Legacy Spec B - Stock, for now
'98 Civic EX - CTR headlights and grill, Kosei K1's, for sale
'90 240SX - SR20DET that will never get installed, project car.