yah well, in n/a cars dholkis DO increase performance....when my car was free flow (no dholki, therefore f*king loud and annoying which i got sick of after a week) it performed just alright, but when i got my first dholki, the "pahtee" whi annoying and loud sound went away, and the performance became a bit better since exhaust flow became a bit better....the sound became extremely nice and smooth and less louder, the more dholkis=less and better sound, loud dholkis=annoying POS driver a more annoying POS car....where as free flow on turbo cars is much better for better flow