Nissan 370Z Forum - View Single Post - About to purchase a F.I. Exhaust and HFC Question

Ronin06 · 07-15-2017, 08:10 AM

OK, I have the FI cat back with 18" resonators. There is a lot of subjective opinions on how loud or acceptable the sound is. So let's turn to science.

Stock readings in decibles

Cold interior 81db
Cold exterior 85db

Warm interior 78db
Warm exterior 80db

FI
Cold interior 92db
Cold exterior 90db* was warming quickly in the summer, actually reading is likely a few db higher.

Warm interior 79db
Warm exterior 85db

Remember every +3db doubles the amount of energy. +10db for perceived loudness.

Personally I found upon initial install I loved the sound at idle, but it was much louder with drone at speed, depending upon load. It's a sound I've grown accustom too, but most of us do not use the Z for a daily driver, at least not for long distance.

07-15-2017, 08:10 AM	#15 (permalink)
Ronin06 Base Member Join Date: Mar 2014 Location: Urbandale, Iowa Posts: 86 Drives: 14 silver sport 370Z Rep Power: 11	OK, I have the FI cat back with 18" resonators. There is a lot of subjective opinions on how loud or acceptable the sound is. So let's turn to science. Stock readings in decibles Cold interior 81db Cold exterior 85db Warm interior 78db Warm exterior 80db FI Cold interior 92db Cold exterior 90db* was warming quickly in the summer, actually reading is likely a few db higher. Warm interior 79db Warm exterior 85db Remember every +3db doubles the amount of energy. +10db for perceived loudness. Personally I found upon initial install I loved the sound at idle, but it was much louder with drone at speed, depending upon load. It's a sound I've grown accustom too, but most of us do not use the Z for a daily driver, at least not for long distance.