How loud is your car in cruise?
#22
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The cutouts would be for dyno days/track events, the other 99% of the time it would be nice and quiet.
My miata had the same magnaflow as most of you guys and it was so much quieter then these duals.
#26
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Tested mine with some free dB meter app, soft top and windows are UP for the tests.
idling in traffic: 55dB
engine off, at stoplight: 49-50dB
cruise top up (40-60mph): 72-74dB
cruise in nuetral same speeds: 67-68dB
WOT: 77-80dB
stereo on: 85-90dB
at worst, the exhaust is adding 7dB to the road/wind noise in cruise. At WOT, most the noise is coming form my intake.
idling in traffic: 55dB
engine off, at stoplight: 49-50dB
cruise top up (40-60mph): 72-74dB
cruise in nuetral same speeds: 67-68dB
WOT: 77-80dB
stereo on: 85-90dB
at worst, the exhaust is adding 7dB to the road/wind noise in cruise. At WOT, most the noise is coming form my intake.
#28
Mine is retarded loud. Ive got one of the quietest exhausts and it doesnt help.
Ive got road noise from the 275s (upgrading to a better tire to reduce noise). Sound from all the gaps. Realigning all the fenders and doors made a difference, and realigning the windows to seal better, helped. Gonna do ttop seals to kill the last of it. And when I finally get around to putting the carpet in, Ive got sound deadener, closed cell foam and some jute im putting down.
I cant stand a loud car anymore.
Ive got road noise from the 275s (upgrading to a better tire to reduce noise). Sound from all the gaps. Realigning all the fenders and doors made a difference, and realigning the windows to seal better, helped. Gonna do ttop seals to kill the last of it. And when I finally get around to putting the carpet in, Ive got sound deadener, closed cell foam and some jute im putting down.
I cant stand a loud car anymore.
#32
When you guys measure dB you MUST measure dBA.
The 'A' weighting mimics the ear's response. Without it you get plain sound energy, and the bass will waaaaaay overstate the numbers.
The quietest straight-through muffler in cruise is probably the Dynomax VT muffler due to its spring loaded flapper:
I did one better and cut the flapper out and installed it after the bigassest Magnaflow 3" muffler that fit. The effect on drone at light throttle was dramatic:
https://www.miataturbo.net/diy-turbo-discussion-14/my-3-custom-exhaust-spring-loaded-flapper-valve-62488/
The 'A' weighting mimics the ear's response. Without it you get plain sound energy, and the bass will waaaaaay overstate the numbers.
The quietest straight-through muffler in cruise is probably the Dynomax VT muffler due to its spring loaded flapper:
I did one better and cut the flapper out and installed it after the bigassest Magnaflow 3" muffler that fit. The effect on drone at light throttle was dramatic:
https://www.miataturbo.net/diy-turbo-discussion-14/my-3-custom-exhaust-spring-loaded-flapper-valve-62488/
#35
I'm running a 3" catback my self.. giant magnaflow muffler like 24" or something along with a 3" resonator and a 3" cat... Quiet as stock or a tiny bit louder. I barely hear it over the turbo whistling.
If i was to do it again, i'd run a cutout right before the cat right after the sensor and leave the stock exhaust on.
Currently its painted black.
If i was to do it again, i'd run a cutout right before the cat right after the sensor and leave the stock exhaust on.
Currently its painted black.
#36
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Any words on the reliability of that flapper? I had heard rumors that it didn't last as long as one would like (forever, really). I like the idea, but I want my exhaust to be forever, like a diamond.
#38
The DSM/EVO guys have been running them for a while, and they tend to get less than a year out of them before they start to clatter at idle. I guess the little fiberglass cushion on the end of the flapper wanders off over time. They are moving a LOT of air, and run their cars quite a bit harder than most of us do, though (EGTs, race gas, etc) so one might last forever in a 300whp Miata where it only lasts months in a 600whp EVO. They also run them in the muffler, where JasonC runs his after the last muffler, so it will run MUCH cooler like that.