Actually, it's hella loud kung NA yung car. Kung turbo, the turbo actually acts as a primary silencer. Some turbo cars run without mufflers at all... (Dodge SRT4).

I think RSR is one (not so sure, ha)... I'm not really up-to-date, you'll have to search the internet to find out. Secondhand chambered mufflers should be examined carefully... as those interior baffles can come loose due to poor handling, vibration or corrosion (I've already lost three mufflers... two aftermarket chambered and one stock chambered... to baffle loosening)... or maybe you can try before you buy.