Why the fock is my car so loud inside!?!?!
07-09-2006, 10:47 AM
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Why the fock is my car so loud inside!?!?! I understand that a lot of the noise comes from the dumped exhaust but it honestly sounds like a drive around with the back hatch open or with gaping hole in the floor. Ive rode in my buddy's Z28 with straight headers and even his car was quieter inside than mine. I dont know if its coming from the doors or hatch or where but if anybody has any ideas where to start let me know! Thanks!
07-09-2006, 11:18 AM
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do you have your back seats in the car or removed? did you switch to a lightweight carpet or remove the sound deadening material on the factory carpet?
these weight reduction mods increase noise dramatically
part of the reason your car is louder inside is because the exhaust is dumped which sends the sound straight down at the ground and it bounces straight back up at bottom of the car. open headers are louder outside but they shoot straight out which gives the sound room to fan out under the car
these weight reduction mods increase noise dramatically
part of the reason your car is louder inside is because the exhaust is dumped which sends the sound straight down at the ground and it bounces straight back up at bottom of the car. open headers are louder outside but they shoot straight out which gives the sound room to fan out under the car
07-11-2006, 06:23 PM
#4
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think of an acoustic guitar. the hole in the acoustic guitar is used to amplify the sound the guitar strings make and projects it across a room so everyone can hear it. dumped exhaust does the same thing. sound waves travel MUCH FURTHER and MUCH FASTER through a solid than they do through a gas. with exhaust out the back, the exhaust note travels through air. with dumps, the exhaust note travels through your car and uses it in a similar fashion to an acoustic guitar. the speed and distance of sound are nearly double through a solid than a gas (your car is a solid, air is a gas 
). if you take the dumps off and bring the exhaust out the back, the exhaust note will travel solely through air, cutting its range and loudness nearly in half.
). if you take the dumps off and bring the exhaust out the back, the exhaust note will travel solely through air, cutting its range and loudness nearly in half.
07-17-2006, 12:45 AM
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I reduced interior db by 10 points just by covering my catback with Thermo-tec products. It's still a little too loud for me, but soon that won't matter. 
I used http://www.thermotec.com/products/full/11600/11600.html for most of the piping aft of the y-pipe (3-foot section covered the I-pipe before the over-the-axle section, 1-foot covered that piece). I also wrapped the muffler with http://www.thermotec.com/products/full/11001/11001.html.
The dump if angled down towards the ground is going to be very loud. Short exhausts typically don't help produce torque, so it may help to put longer pipes back on, just to improve the torque curve (may reduce unwanted attention from the cops, too)
HTH, Rob
I used http://www.thermotec.com/products/full/11600/11600.html for most of the piping aft of the y-pipe (3-foot section covered the I-pipe before the over-the-axle section, 1-foot covered that piece). I also wrapped the muffler with http://www.thermotec.com/products/full/11001/11001.html.
The dump if angled down towards the ground is going to be very loud. Short exhausts typically don't help produce torque, so it may help to put longer pipes back on, just to improve the torque curve (may reduce unwanted attention from the cops, too)
HTH, Rob
